Merge branch 'work/adridg/remove-boost' into calamares

3rdparty/pybind11/CMakeLists.txt

@@ -0,0 +1,16 @@
+# === This file is part of Calamares - <https://calamares.io> ===
+#
+#   SPDX-FileCopyrightText: 2023 Adriaan de Groot <groot@kde.org>
+#   SPDX-License-Identifier: BSD-2-Clause
+#
+###
+#
+# This is a very-stripped-down way of getting the bundled pybind11
+
+add_library(pybind11_headers INTERFACE)
+add_library(pybind11::headers ALIAS pybind11_headers)
+
+target_include_directories(pybind11_headers INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/include)
+target_link_libraries(pybind11_headers INTERFACE Python::Python) # Was searched-for at top-level
+
+

3rdparty/pybind11/LICENSE

@@ -0,0 +1,29 @@
+Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>, All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+Please also refer to the file .github/CONTRIBUTING.md, which clarifies licensing of
+external contributions to this project including patches, pull requests, etc.

3rdparty/pybind11/MANIFEST.in

@@ -0,0 +1,6 @@
+prune tests
+recursive-include pybind11/include/pybind11 *.h
+recursive-include pybind11 *.py
+recursive-include pybind11 py.typed
+include pybind11/share/cmake/pybind11/*.cmake
+include LICENSE README.rst SECURITY.md pyproject.toml setup.py setup.cfg

3rdparty/pybind11/README.rst

@@ -0,0 +1,180 @@
+.. figure:: https://github.com/pybind/pybind11/raw/master/docs/pybind11-logo.png
+   :alt: pybind11 logo
+
+**pybind11 — Seamless operability between C++11 and Python**
+
+|Latest Documentation Status| |Stable Documentation Status| |Gitter chat| |GitHub Discussions| |CI| |Build status|
+
+|Repology| |PyPI package| |Conda-forge| |Python Versions|
+
+`Setuptools example <https://github.com/pybind/python_example>`_
+• `Scikit-build example <https://github.com/pybind/scikit_build_example>`_
+• `CMake example <https://github.com/pybind/cmake_example>`_
+
+.. start
+
+
+**pybind11** is a lightweight header-only library that exposes C++ types
+in Python and vice versa, mainly to create Python bindings of existing
+C++ code. Its goals and syntax are similar to the excellent
+`Boost.Python <http://www.boost.org/doc/libs/1_58_0/libs/python/doc/>`_
+library by David Abrahams: to minimize boilerplate code in traditional
+extension modules by inferring type information using compile-time
+introspection.
+
+The main issue with Boost.Python—and the reason for creating such a
+similar project—is Boost. Boost is an enormously large and complex suite
+of utility libraries that works with almost every C++ compiler in
+existence. This compatibility has its cost: arcane template tricks and
+workarounds are necessary to support the oldest and buggiest of compiler
+specimens. Now that C++11-compatible compilers are widely available,
+this heavy machinery has become an excessively large and unnecessary
+dependency.
+
+Think of this library as a tiny self-contained version of Boost.Python
+with everything stripped away that isn't relevant for binding
+generation. Without comments, the core header files only require ~4K
+lines of code and depend on Python (3.6+, or PyPy) and the C++
+standard library. This compact implementation was possible thanks to
+some of the new C++11 language features (specifically: tuples, lambda
+functions and variadic templates). Since its creation, this library has
+grown beyond Boost.Python in many ways, leading to dramatically simpler
+binding code in many common situations.
+
+Tutorial and reference documentation is provided at
+`pybind11.readthedocs.io <https://pybind11.readthedocs.io/en/latest>`_.
+A PDF version of the manual is available
+`here <https://pybind11.readthedocs.io/_/downloads/en/latest/pdf/>`_.
+And the source code is always available at
+`github.com/pybind/pybind11 <https://github.com/pybind/pybind11>`_.
+
+
+Core features
+-------------
+
+
+pybind11 can map the following core C++ features to Python:
+
+- Functions accepting and returning custom data structures per value,
+  reference, or pointer
+- Instance methods and static methods
+- Overloaded functions
+- Instance attributes and static attributes
+- Arbitrary exception types
+- Enumerations
+- Callbacks
+- Iterators and ranges
+- Custom operators
+- Single and multiple inheritance
+- STL data structures
+- Smart pointers with reference counting like ``std::shared_ptr``
+- Internal references with correct reference counting
+- C++ classes with virtual (and pure virtual) methods can be extended
+  in Python
+
+Goodies
+-------
+
+In addition to the core functionality, pybind11 provides some extra
+goodies:
+
+- Python 3.6+, and PyPy3 7.3 are supported with an implementation-agnostic
+  interface (pybind11 2.9 was the last version to support Python 2 and 3.5).
+
+- It is possible to bind C++11 lambda functions with captured
+  variables. The lambda capture data is stored inside the resulting
+  Python function object.
+
+- pybind11 uses C++11 move constructors and move assignment operators
+  whenever possible to efficiently transfer custom data types.
+
+- It's easy to expose the internal storage of custom data types through
+  Pythons' buffer protocols. This is handy e.g. for fast conversion
+  between C++ matrix classes like Eigen and NumPy without expensive
+  copy operations.
+
+- pybind11 can automatically vectorize functions so that they are
+  transparently applied to all entries of one or more NumPy array
+  arguments.
+
+- Python's slice-based access and assignment operations can be
+  supported with just a few lines of code.
+
+- Everything is contained in just a few header files; there is no need
+  to link against any additional libraries.
+
+- Binaries are generally smaller by a factor of at least 2 compared to
+  equivalent bindings generated by Boost.Python. A recent pybind11
+  conversion of PyRosetta, an enormous Boost.Python binding project,
+  `reported <https://graylab.jhu.edu/Sergey/2016.RosettaCon/PyRosetta-4.pdf>`_
+  a binary size reduction of **5.4x** and compile time reduction by
+  **5.8x**.
+
+- Function signatures are precomputed at compile time (using
+  ``constexpr``), leading to smaller binaries.
+
+- With little extra effort, C++ types can be pickled and unpickled
+  similar to regular Python objects.
+
+Supported compilers
+-------------------
+
+1. Clang/LLVM 3.3 or newer (for Apple Xcode's clang, this is 5.0.0 or
+   newer)
+2. GCC 4.8 or newer
+3. Microsoft Visual Studio 2017 or newer
+4. Intel classic C++ compiler 18 or newer (ICC 20.2 tested in CI)
+5. Cygwin/GCC (previously tested on 2.5.1)
+6. NVCC (CUDA 11.0 tested in CI)
+7. NVIDIA PGI (20.9 tested in CI)
+
+About
+-----
+
+This project was created by `Wenzel
+Jakob <http://rgl.epfl.ch/people/wjakob>`_. Significant features and/or
+improvements to the code were contributed by Jonas Adler, Lori A. Burns,
+Sylvain Corlay, Eric Cousineau, Aaron Gokaslan, Ralf Grosse-Kunstleve, Trent Houliston, Axel
+Huebl, @hulucc, Yannick Jadoul, Sergey Lyskov, Johan Mabille, Tomasz Miąsko,
+Dean Moldovan, Ben Pritchard, Jason Rhinelander, Boris Schäling, Pim
+Schellart, Henry Schreiner, Ivan Smirnov, Boris Staletic, and Patrick Stewart.
+
+We thank Google for a generous financial contribution to the continuous
+integration infrastructure used by this project.
+
+
+Contributing
+~~~~~~~~~~~~
+
+See the `contributing
+guide <https://github.com/pybind/pybind11/blob/master/.github/CONTRIBUTING.md>`_
+for information on building and contributing to pybind11.
+
+License
+~~~~~~~
+
+pybind11 is provided under a BSD-style license that can be found in the
+`LICENSE <https://github.com/pybind/pybind11/blob/master/LICENSE>`_
+file. By using, distributing, or contributing to this project, you agree
+to the terms and conditions of this license.
+
+.. |Latest Documentation Status| image:: https://readthedocs.org/projects/pybind11/badge?version=latest
+   :target: http://pybind11.readthedocs.org/en/latest
+.. |Stable Documentation Status| image:: https://img.shields.io/badge/docs-stable-blue.svg
+   :target: http://pybind11.readthedocs.org/en/stable
+.. |Gitter chat| image:: https://img.shields.io/gitter/room/gitterHQ/gitter.svg
+   :target: https://gitter.im/pybind/Lobby
+.. |CI| image:: https://github.com/pybind/pybind11/workflows/CI/badge.svg
+   :target: https://github.com/pybind/pybind11/actions
+.. |Build status| image:: https://ci.appveyor.com/api/projects/status/riaj54pn4h08xy40?svg=true
+   :target: https://ci.appveyor.com/project/wjakob/pybind11
+.. |PyPI package| image:: https://img.shields.io/pypi/v/pybind11.svg
+   :target: https://pypi.org/project/pybind11/
+.. |Conda-forge| image:: https://img.shields.io/conda/vn/conda-forge/pybind11.svg
+   :target: https://github.com/conda-forge/pybind11-feedstock
+.. |Repology| image:: https://repology.org/badge/latest-versions/python:pybind11.svg
+   :target: https://repology.org/project/python:pybind11/versions
+.. |Python Versions| image:: https://img.shields.io/pypi/pyversions/pybind11.svg
+   :target: https://pypi.org/project/pybind11/
+.. |GitHub Discussions| image:: https://img.shields.io/static/v1?label=Discussions&message=Ask&color=blue&logo=github
+   :target: https://github.com/pybind/pybind11/discussions

3rdparty/pybind11/SECURITY.md

@@ -0,0 +1,13 @@
+# Security Policy
+
+## Supported Versions
+
+Security updates are applied only to the latest release.
+
+## Reporting a Vulnerability
+
+If you have discovered a security vulnerability in this project, please report it privately. **Do not disclose it as a public issue.** This gives us time to work with you to fix the issue before public exposure, reducing the chance that the exploit will be used before a patch is released.
+
+Please disclose it at [security advisory](https://github.com/pybind/pybind11/security/advisories/new).
+
+This project is maintained by a team of volunteers on a reasonable-effort basis. As such, please give us at least 90 days to work on a fix before public exposure.

3rdparty/pybind11/include/pybind11/attr.h

@@ -0,0 +1,690 @@
+/*
+    pybind11/attr.h: Infrastructure for processing custom
+    type and function attributes
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "detail/common.h"
+#include "cast.h"
+
+#include <functional>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+/// \addtogroup annotations
+/// @{
+
+/// Annotation for methods
+struct is_method {
+    handle class_;
+    explicit is_method(const handle &c) : class_(c) {}
+};
+
+/// Annotation for setters
+struct is_setter {};
+
+/// Annotation for operators
+struct is_operator {};
+
+/// Annotation for classes that cannot be subclassed
+struct is_final {};
+
+/// Annotation for parent scope
+struct scope {
+    handle value;
+    explicit scope(const handle &s) : value(s) {}
+};
+
+/// Annotation for documentation
+struct doc {
+    const char *value;
+    explicit doc(const char *value) : value(value) {}
+};
+
+/// Annotation for function names
+struct name {
+    const char *value;
+    explicit name(const char *value) : value(value) {}
+};
+
+/// Annotation indicating that a function is an overload associated with a given "sibling"
+struct sibling {
+    handle value;
+    explicit sibling(const handle &value) : value(value.ptr()) {}
+};
+
+/// Annotation indicating that a class derives from another given type
+template <typename T>
+struct base {
+
+    PYBIND11_DEPRECATED(
+        "base<T>() was deprecated in favor of specifying 'T' as a template argument to class_")
+    base() = default;
+};
+
+/// Keep patient alive while nurse lives
+template <size_t Nurse, size_t Patient>
+struct keep_alive {};
+
+/// Annotation indicating that a class is involved in a multiple inheritance relationship
+struct multiple_inheritance {};
+
+/// Annotation which enables dynamic attributes, i.e. adds `__dict__` to a class
+struct dynamic_attr {};
+
+/// Annotation which enables the buffer protocol for a type
+struct buffer_protocol {};
+
+/// Annotation which requests that a special metaclass is created for a type
+struct metaclass {
+    handle value;
+
+    PYBIND11_DEPRECATED("py::metaclass() is no longer required. It's turned on by default now.")
+    metaclass() = default;
+
+    /// Override pybind11's default metaclass
+    explicit metaclass(handle value) : value(value) {}
+};
+
+/// Specifies a custom callback with signature `void (PyHeapTypeObject*)` that
+/// may be used to customize the Python type.
+///
+/// The callback is invoked immediately before `PyType_Ready`.
+///
+/// Note: This is an advanced interface, and uses of it may require changes to
+/// work with later versions of pybind11.  You may wish to consult the
+/// implementation of `make_new_python_type` in `detail/classes.h` to understand
+/// the context in which the callback will be run.
+struct custom_type_setup {
+    using callback = std::function<void(PyHeapTypeObject *heap_type)>;
+
+    explicit custom_type_setup(callback value) : value(std::move(value)) {}
+
+    callback value;
+};
+
+/// Annotation that marks a class as local to the module:
+struct module_local {
+    const bool value;
+    constexpr explicit module_local(bool v = true) : value(v) {}
+};
+
+/// Annotation to mark enums as an arithmetic type
+struct arithmetic {};
+
+/// Mark a function for addition at the beginning of the existing overload chain instead of the end
+struct prepend {};
+
+/** \rst
+    A call policy which places one or more guard variables (``Ts...``) around the function call.
+
+    For example, this definition:
+
+    .. code-block:: cpp
+
+        m.def("foo", foo, py::call_guard<T>());
+
+    is equivalent to the following pseudocode:
+
+    .. code-block:: cpp
+
+        m.def("foo", [](args...) {
+            T scope_guard;
+            return foo(args...); // forwarded arguments
+        });
+ \endrst */
+template <typename... Ts>
+struct call_guard;
+
+template <>
+struct call_guard<> {
+    using type = detail::void_type;
+};
+
+template <typename T>
+struct call_guard<T> {
+    static_assert(std::is_default_constructible<T>::value,
+                  "The guard type must be default constructible");
+
+    using type = T;
+};
+
+template <typename T, typename... Ts>
+struct call_guard<T, Ts...> {
+    struct type {
+        T guard{}; // Compose multiple guard types with left-to-right default-constructor order
+        typename call_guard<Ts...>::type next{};
+    };
+};
+
+/// @} annotations
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+/* Forward declarations */
+enum op_id : int;
+enum op_type : int;
+struct undefined_t;
+template <op_id id, op_type ot, typename L = undefined_t, typename R = undefined_t>
+struct op_;
+void keep_alive_impl(size_t Nurse, size_t Patient, function_call &call, handle ret);
+
+/// Internal data structure which holds metadata about a keyword argument
+struct argument_record {
+    const char *name;  ///< Argument name
+    const char *descr; ///< Human-readable version of the argument value
+    handle value;      ///< Associated Python object
+    bool convert : 1;  ///< True if the argument is allowed to convert when loading
+    bool none : 1;     ///< True if None is allowed when loading
+
+    argument_record(const char *name, const char *descr, handle value, bool convert, bool none)
+        : name(name), descr(descr), value(value), convert(convert), none(none) {}
+};
+
+/// Internal data structure which holds metadata about a bound function (signature, overloads,
+/// etc.)
+struct function_record {
+    function_record()
+        : is_constructor(false), is_new_style_constructor(false), is_stateless(false),
+          is_operator(false), is_method(false), is_setter(false), has_args(false),
+          has_kwargs(false), prepend(false) {}
+
+    /// Function name
+    char *name = nullptr; /* why no C++ strings? They generate heavier code.. */
+
+    // User-specified documentation string
+    char *doc = nullptr;
+
+    /// Human-readable version of the function signature
+    char *signature = nullptr;
+
+    /// List of registered keyword arguments
+    std::vector<argument_record> args;
+
+    /// Pointer to lambda function which converts arguments and performs the actual call
+    handle (*impl)(function_call &) = nullptr;
+
+    /// Storage for the wrapped function pointer and captured data, if any
+    void *data[3] = {};
+
+    /// Pointer to custom destructor for 'data' (if needed)
+    void (*free_data)(function_record *ptr) = nullptr;
+
+    /// Return value policy associated with this function
+    return_value_policy policy = return_value_policy::automatic;
+
+    /// True if name == '__init__'
+    bool is_constructor : 1;
+
+    /// True if this is a new-style `__init__` defined in `detail/init.h`
+    bool is_new_style_constructor : 1;
+
+    /// True if this is a stateless function pointer
+    bool is_stateless : 1;
+
+    /// True if this is an operator (__add__), etc.
+    bool is_operator : 1;
+
+    /// True if this is a method
+    bool is_method : 1;
+
+    /// True if this is a setter
+    bool is_setter : 1;
+
+    /// True if the function has a '*args' argument
+    bool has_args : 1;
+
+    /// True if the function has a '**kwargs' argument
+    bool has_kwargs : 1;
+
+    /// True if this function is to be inserted at the beginning of the overload resolution chain
+    bool prepend : 1;
+
+    /// Number of arguments (including py::args and/or py::kwargs, if present)
+    std::uint16_t nargs;
+
+    /// Number of leading positional arguments, which are terminated by a py::args or py::kwargs
+    /// argument or by a py::kw_only annotation.
+    std::uint16_t nargs_pos = 0;
+
+    /// Number of leading arguments (counted in `nargs`) that are positional-only
+    std::uint16_t nargs_pos_only = 0;
+
+    /// Python method object
+    PyMethodDef *def = nullptr;
+
+    /// Python handle to the parent scope (a class or a module)
+    handle scope;
+
+    /// Python handle to the sibling function representing an overload chain
+    handle sibling;
+
+    /// Pointer to next overload
+    function_record *next = nullptr;
+};
+
+/// Special data structure which (temporarily) holds metadata about a bound class
+struct type_record {
+    PYBIND11_NOINLINE type_record()
+        : multiple_inheritance(false), dynamic_attr(false), buffer_protocol(false),
+          default_holder(true), module_local(false), is_final(false) {}
+
+    /// Handle to the parent scope
+    handle scope;
+
+    /// Name of the class
+    const char *name = nullptr;
+
+    // Pointer to RTTI type_info data structure
+    const std::type_info *type = nullptr;
+
+    /// How large is the underlying C++ type?
+    size_t type_size = 0;
+
+    /// What is the alignment of the underlying C++ type?
+    size_t type_align = 0;
+
+    /// How large is the type's holder?
+    size_t holder_size = 0;
+
+    /// The global operator new can be overridden with a class-specific variant
+    void *(*operator_new)(size_t) = nullptr;
+
+    /// Function pointer to class_<..>::init_instance
+    void (*init_instance)(instance *, const void *) = nullptr;
+
+    /// Function pointer to class_<..>::dealloc
+    void (*dealloc)(detail::value_and_holder &) = nullptr;
+
+    /// List of base classes of the newly created type
+    list bases;
+
+    /// Optional docstring
+    const char *doc = nullptr;
+
+    /// Custom metaclass (optional)
+    handle metaclass;
+
+    /// Custom type setup.
+    custom_type_setup::callback custom_type_setup_callback;
+
+    /// Multiple inheritance marker
+    bool multiple_inheritance : 1;
+
+    /// Does the class manage a __dict__?
+    bool dynamic_attr : 1;
+
+    /// Does the class implement the buffer protocol?
+    bool buffer_protocol : 1;
+
+    /// Is the default (unique_ptr) holder type used?
+    bool default_holder : 1;
+
+    /// Is the class definition local to the module shared object?
+    bool module_local : 1;
+
+    /// Is the class inheritable from python classes?
+    bool is_final : 1;
+
+    PYBIND11_NOINLINE void add_base(const std::type_info &base, void *(*caster)(void *) ) {
+        auto *base_info = detail::get_type_info(base, false);
+        if (!base_info) {
+            std::string tname(base.name());
+            detail::clean_type_id(tname);
+            pybind11_fail("generic_type: type \"" + std::string(name)
+                          + "\" referenced unknown base type \"" + tname + "\"");
+        }
+
+        if (default_holder != base_info->default_holder) {
+            std::string tname(base.name());
+            detail::clean_type_id(tname);
+            pybind11_fail("generic_type: type \"" + std::string(name) + "\" "
+                          + (default_holder ? "does not have" : "has")
+                          + " a non-default holder type while its base \"" + tname + "\" "
+                          + (base_info->default_holder ? "does not" : "does"));
+        }
+
+        bases.append((PyObject *) base_info->type);
+
+#if PY_VERSION_HEX < 0x030B0000
+        dynamic_attr |= base_info->type->tp_dictoffset != 0;
+#else
+        dynamic_attr |= (base_info->type->tp_flags & Py_TPFLAGS_MANAGED_DICT) != 0;
+#endif
+
+        if (caster) {
+            base_info->implicit_casts.emplace_back(type, caster);
+        }
+    }
+};
+
+inline function_call::function_call(const function_record &f, handle p) : func(f), parent(p) {
+    args.reserve(f.nargs);
+    args_convert.reserve(f.nargs);
+}
+
+/// Tag for a new-style `__init__` defined in `detail/init.h`
+struct is_new_style_constructor {};
+
+/**
+ * Partial template specializations to process custom attributes provided to
+ * cpp_function_ and class_. These are either used to initialize the respective
+ * fields in the type_record and function_record data structures or executed at
+ * runtime to deal with custom call policies (e.g. keep_alive).
+ */
+template <typename T, typename SFINAE = void>
+struct process_attribute;
+
+template <typename T>
+struct process_attribute_default {
+    /// Default implementation: do nothing
+    static void init(const T &, function_record *) {}
+    static void init(const T &, type_record *) {}
+    static void precall(function_call &) {}
+    static void postcall(function_call &, handle) {}
+};
+
+/// Process an attribute specifying the function's name
+template <>
+struct process_attribute<name> : process_attribute_default<name> {
+    static void init(const name &n, function_record *r) { r->name = const_cast<char *>(n.value); }
+};
+
+/// Process an attribute specifying the function's docstring
+template <>
+struct process_attribute<doc> : process_attribute_default<doc> {
+    static void init(const doc &n, function_record *r) { r->doc = const_cast<char *>(n.value); }
+};
+
+/// Process an attribute specifying the function's docstring (provided as a C-style string)
+template <>
+struct process_attribute<const char *> : process_attribute_default<const char *> {
+    static void init(const char *d, function_record *r) { r->doc = const_cast<char *>(d); }
+    static void init(const char *d, type_record *r) { r->doc = d; }
+};
+template <>
+struct process_attribute<char *> : process_attribute<const char *> {};
+
+/// Process an attribute indicating the function's return value policy
+template <>
+struct process_attribute<return_value_policy> : process_attribute_default<return_value_policy> {
+    static void init(const return_value_policy &p, function_record *r) { r->policy = p; }
+};
+
+/// Process an attribute which indicates that this is an overloaded function associated with a
+/// given sibling
+template <>
+struct process_attribute<sibling> : process_attribute_default<sibling> {
+    static void init(const sibling &s, function_record *r) { r->sibling = s.value; }
+};
+
+/// Process an attribute which indicates that this function is a method
+template <>
+struct process_attribute<is_method> : process_attribute_default<is_method> {
+    static void init(const is_method &s, function_record *r) {
+        r->is_method = true;
+        r->scope = s.class_;
+    }
+};
+
+/// Process an attribute which indicates that this function is a setter
+template <>
+struct process_attribute<is_setter> : process_attribute_default<is_setter> {
+    static void init(const is_setter &, function_record *r) { r->is_setter = true; }
+};
+
+/// Process an attribute which indicates the parent scope of a method
+template <>
+struct process_attribute<scope> : process_attribute_default<scope> {
+    static void init(const scope &s, function_record *r) { r->scope = s.value; }
+};
+
+/// Process an attribute which indicates that this function is an operator
+template <>
+struct process_attribute<is_operator> : process_attribute_default<is_operator> {
+    static void init(const is_operator &, function_record *r) { r->is_operator = true; }
+};
+
+template <>
+struct process_attribute<is_new_style_constructor>
+    : process_attribute_default<is_new_style_constructor> {
+    static void init(const is_new_style_constructor &, function_record *r) {
+        r->is_new_style_constructor = true;
+    }
+};
+
+inline void check_kw_only_arg(const arg &a, function_record *r) {
+    if (r->args.size() > r->nargs_pos && (!a.name || a.name[0] == '\0')) {
+        pybind11_fail("arg(): cannot specify an unnamed argument after a kw_only() annotation or "
+                      "args() argument");
+    }
+}
+
+inline void append_self_arg_if_needed(function_record *r) {
+    if (r->is_method && r->args.empty()) {
+        r->args.emplace_back("self", nullptr, handle(), /*convert=*/true, /*none=*/false);
+    }
+}
+
+/// Process a keyword argument attribute (*without* a default value)
+template <>
+struct process_attribute<arg> : process_attribute_default<arg> {
+    static void init(const arg &a, function_record *r) {
+        append_self_arg_if_needed(r);
+        r->args.emplace_back(a.name, nullptr, handle(), !a.flag_noconvert, a.flag_none);
+
+        check_kw_only_arg(a, r);
+    }
+};
+
+/// Process a keyword argument attribute (*with* a default value)
+template <>
+struct process_attribute<arg_v> : process_attribute_default<arg_v> {
+    static void init(const arg_v &a, function_record *r) {
+        if (r->is_method && r->args.empty()) {
+            r->args.emplace_back(
+                "self", /*descr=*/nullptr, /*parent=*/handle(), /*convert=*/true, /*none=*/false);
+        }
+
+        if (!a.value) {
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
+            std::string descr("'");
+            if (a.name) {
+                descr += std::string(a.name) + ": ";
+            }
+            descr += a.type + "'";
+            if (r->is_method) {
+                if (r->name) {
+                    descr += " in method '" + (std::string) str(r->scope) + "."
+                             + (std::string) r->name + "'";
+                } else {
+                    descr += " in method of '" + (std::string) str(r->scope) + "'";
+                }
+            } else if (r->name) {
+                descr += " in function '" + (std::string) r->name + "'";
+            }
+            pybind11_fail("arg(): could not convert default argument " + descr
+                          + " into a Python object (type not registered yet?)");
+#else
+            pybind11_fail("arg(): could not convert default argument "
+                          "into a Python object (type not registered yet?). "
+                          "#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for "
+                          "more information.");
+#endif
+        }
+        r->args.emplace_back(a.name, a.descr, a.value.inc_ref(), !a.flag_noconvert, a.flag_none);
+
+        check_kw_only_arg(a, r);
+    }
+};
+
+/// Process a keyword-only-arguments-follow pseudo argument
+template <>
+struct process_attribute<kw_only> : process_attribute_default<kw_only> {
+    static void init(const kw_only &, function_record *r) {
+        append_self_arg_if_needed(r);
+        if (r->has_args && r->nargs_pos != static_cast<std::uint16_t>(r->args.size())) {
+            pybind11_fail("Mismatched args() and kw_only(): they must occur at the same relative "
+                          "argument location (or omit kw_only() entirely)");
+        }
+        r->nargs_pos = static_cast<std::uint16_t>(r->args.size());
+    }
+};
+
+/// Process a positional-only-argument maker
+template <>
+struct process_attribute<pos_only> : process_attribute_default<pos_only> {
+    static void init(const pos_only &, function_record *r) {
+        append_self_arg_if_needed(r);
+        r->nargs_pos_only = static_cast<std::uint16_t>(r->args.size());
+        if (r->nargs_pos_only > r->nargs_pos) {
+            pybind11_fail("pos_only(): cannot follow a py::args() argument");
+        }
+        // It also can't follow a kw_only, but a static_assert in pybind11.h checks that
+    }
+};
+
+/// Process a parent class attribute.  Single inheritance only (class_ itself already guarantees
+/// that)
+template <typename T>
+struct process_attribute<T, enable_if_t<is_pyobject<T>::value>>
+    : process_attribute_default<handle> {
+    static void init(const handle &h, type_record *r) { r->bases.append(h); }
+};
+
+/// Process a parent class attribute (deprecated, does not support multiple inheritance)
+template <typename T>
+struct process_attribute<base<T>> : process_attribute_default<base<T>> {
+    static void init(const base<T> &, type_record *r) { r->add_base(typeid(T), nullptr); }
+};
+
+/// Process a multiple inheritance attribute
+template <>
+struct process_attribute<multiple_inheritance> : process_attribute_default<multiple_inheritance> {
+    static void init(const multiple_inheritance &, type_record *r) {
+        r->multiple_inheritance = true;
+    }
+};
+
+template <>
+struct process_attribute<dynamic_attr> : process_attribute_default<dynamic_attr> {
+    static void init(const dynamic_attr &, type_record *r) { r->dynamic_attr = true; }
+};
+
+template <>
+struct process_attribute<custom_type_setup> {
+    static void init(const custom_type_setup &value, type_record *r) {
+        r->custom_type_setup_callback = value.value;
+    }
+};
+
+template <>
+struct process_attribute<is_final> : process_attribute_default<is_final> {
+    static void init(const is_final &, type_record *r) { r->is_final = true; }
+};
+
+template <>
+struct process_attribute<buffer_protocol> : process_attribute_default<buffer_protocol> {
+    static void init(const buffer_protocol &, type_record *r) { r->buffer_protocol = true; }
+};
+
+template <>
+struct process_attribute<metaclass> : process_attribute_default<metaclass> {
+    static void init(const metaclass &m, type_record *r) { r->metaclass = m.value; }
+};
+
+template <>
+struct process_attribute<module_local> : process_attribute_default<module_local> {
+    static void init(const module_local &l, type_record *r) { r->module_local = l.value; }
+};
+
+/// Process a 'prepend' attribute, putting this at the beginning of the overload chain
+template <>
+struct process_attribute<prepend> : process_attribute_default<prepend> {
+    static void init(const prepend &, function_record *r) { r->prepend = true; }
+};
+
+/// Process an 'arithmetic' attribute for enums (does nothing here)
+template <>
+struct process_attribute<arithmetic> : process_attribute_default<arithmetic> {};
+
+template <typename... Ts>
+struct process_attribute<call_guard<Ts...>> : process_attribute_default<call_guard<Ts...>> {};
+
+/**
+ * Process a keep_alive call policy -- invokes keep_alive_impl during the
+ * pre-call handler if both Nurse, Patient != 0 and use the post-call handler
+ * otherwise
+ */
+template <size_t Nurse, size_t Patient>
+struct process_attribute<keep_alive<Nurse, Patient>>
+    : public process_attribute_default<keep_alive<Nurse, Patient>> {
+    template <size_t N = Nurse, size_t P = Patient, enable_if_t<N != 0 && P != 0, int> = 0>
+    static void precall(function_call &call) {
+        keep_alive_impl(Nurse, Patient, call, handle());
+    }
+    template <size_t N = Nurse, size_t P = Patient, enable_if_t<N != 0 && P != 0, int> = 0>
+    static void postcall(function_call &, handle) {}
+    template <size_t N = Nurse, size_t P = Patient, enable_if_t<N == 0 || P == 0, int> = 0>
+    static void precall(function_call &) {}
+    template <size_t N = Nurse, size_t P = Patient, enable_if_t<N == 0 || P == 0, int> = 0>
+    static void postcall(function_call &call, handle ret) {
+        keep_alive_impl(Nurse, Patient, call, ret);
+    }
+};
+
+/// Recursively iterate over variadic template arguments
+template <typename... Args>
+struct process_attributes {
+    static void init(const Args &...args, function_record *r) {
+        PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(r);
+        PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(r);
+        using expander = int[];
+        (void) expander{
+            0, ((void) process_attribute<typename std::decay<Args>::type>::init(args, r), 0)...};
+    }
+    static void init(const Args &...args, type_record *r) {
+        PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(r);
+        PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(r);
+        using expander = int[];
+        (void) expander{0,
+                        (process_attribute<typename std::decay<Args>::type>::init(args, r), 0)...};
+    }
+    static void precall(function_call &call) {
+        PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(call);
+        using expander = int[];
+        (void) expander{0,
+                        (process_attribute<typename std::decay<Args>::type>::precall(call), 0)...};
+    }
+    static void postcall(function_call &call, handle fn_ret) {
+        PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(call, fn_ret);
+        PYBIND11_WORKAROUND_INCORRECT_GCC_UNUSED_BUT_SET_PARAMETER(fn_ret);
+        using expander = int[];
+        (void) expander{
+            0, (process_attribute<typename std::decay<Args>::type>::postcall(call, fn_ret), 0)...};
+    }
+};
+
+template <typename T>
+using is_call_guard = is_instantiation<call_guard, T>;
+
+/// Extract the ``type`` from the first `call_guard` in `Extras...` (or `void_type` if none found)
+template <typename... Extra>
+using extract_guard_t = typename exactly_one_t<is_call_guard, call_guard<>, Extra...>::type;
+
+/// Check the number of named arguments at compile time
+template <typename... Extra,
+          size_t named = constexpr_sum(std::is_base_of<arg, Extra>::value...),
+          size_t self = constexpr_sum(std::is_same<is_method, Extra>::value...)>
+constexpr bool expected_num_args(size_t nargs, bool has_args, bool has_kwargs) {
+    PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(nargs, has_args, has_kwargs);
+    return named == 0 || (self + named + size_t(has_args) + size_t(has_kwargs)) == nargs;
+}
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/buffer_info.h

@@ -0,0 +1,208 @@
+/*
+    pybind11/buffer_info.h: Python buffer object interface
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "detail/common.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+// Default, C-style strides
+inline std::vector<ssize_t> c_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
+    auto ndim = shape.size();
+    std::vector<ssize_t> strides(ndim, itemsize);
+    if (ndim > 0) {
+        for (size_t i = ndim - 1; i > 0; --i) {
+            strides[i - 1] = strides[i] * shape[i];
+        }
+    }
+    return strides;
+}
+
+// F-style strides; default when constructing an array_t with `ExtraFlags & f_style`
+inline std::vector<ssize_t> f_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
+    auto ndim = shape.size();
+    std::vector<ssize_t> strides(ndim, itemsize);
+    for (size_t i = 1; i < ndim; ++i) {
+        strides[i] = strides[i - 1] * shape[i - 1];
+    }
+    return strides;
+}
+
+template <typename T, typename SFINAE = void>
+struct compare_buffer_info;
+
+PYBIND11_NAMESPACE_END(detail)
+
+/// Information record describing a Python buffer object
+struct buffer_info {
+    void *ptr = nullptr;          // Pointer to the underlying storage
+    ssize_t itemsize = 0;         // Size of individual items in bytes
+    ssize_t size = 0;             // Total number of entries
+    std::string format;           // For homogeneous buffers, this should be set to
+                                  // format_descriptor<T>::format()
+    ssize_t ndim = 0;             // Number of dimensions
+    std::vector<ssize_t> shape;   // Shape of the tensor (1 entry per dimension)
+    std::vector<ssize_t> strides; // Number of bytes between adjacent entries
+                                  // (for each per dimension)
+    bool readonly = false;        // flag to indicate if the underlying storage may be written to
+
+    buffer_info() = default;
+
+    buffer_info(void *ptr,
+                ssize_t itemsize,
+                const std::string &format,
+                ssize_t ndim,
+                detail::any_container<ssize_t> shape_in,
+                detail::any_container<ssize_t> strides_in,
+                bool readonly = false)
+        : ptr(ptr), itemsize(itemsize), size(1), format(format), ndim(ndim),
+          shape(std::move(shape_in)), strides(std::move(strides_in)), readonly(readonly) {
+        if (ndim != (ssize_t) shape.size() || ndim != (ssize_t) strides.size()) {
+            pybind11_fail("buffer_info: ndim doesn't match shape and/or strides length");
+        }
+        for (size_t i = 0; i < (size_t) ndim; ++i) {
+            size *= shape[i];
+        }
+    }
+
+    template <typename T>
+    buffer_info(T *ptr,
+                detail::any_container<ssize_t> shape_in,
+                detail::any_container<ssize_t> strides_in,
+                bool readonly = false)
+        : buffer_info(private_ctr_tag(),
+                      ptr,
+                      sizeof(T),
+                      format_descriptor<T>::format(),
+                      static_cast<ssize_t>(shape_in->size()),
+                      std::move(shape_in),
+                      std::move(strides_in),
+                      readonly) {}
+
+    buffer_info(void *ptr,
+                ssize_t itemsize,
+                const std::string &format,
+                ssize_t size,
+                bool readonly = false)
+        : buffer_info(ptr, itemsize, format, 1, {size}, {itemsize}, readonly) {}
+
+    template <typename T>
+    buffer_info(T *ptr, ssize_t size, bool readonly = false)
+        : buffer_info(ptr, sizeof(T), format_descriptor<T>::format(), size, readonly) {}
+
+    template <typename T>
+    buffer_info(const T *ptr, ssize_t size, bool readonly = true)
+        : buffer_info(
+            const_cast<T *>(ptr), sizeof(T), format_descriptor<T>::format(), size, readonly) {}
+
+    explicit buffer_info(Py_buffer *view, bool ownview = true)
+        : buffer_info(
+            view->buf,
+            view->itemsize,
+            view->format,
+            view->ndim,
+            {view->shape, view->shape + view->ndim},
+            /* Though buffer::request() requests PyBUF_STRIDES, ctypes objects
+             * ignore this flag and return a view with NULL strides.
+             * When strides are NULL, build them manually.  */
+            view->strides
+                ? std::vector<ssize_t>(view->strides, view->strides + view->ndim)
+                : detail::c_strides({view->shape, view->shape + view->ndim}, view->itemsize),
+            (view->readonly != 0)) {
+        // NOLINTNEXTLINE(cppcoreguidelines-prefer-member-initializer)
+        this->m_view = view;
+        // NOLINTNEXTLINE(cppcoreguidelines-prefer-member-initializer)
+        this->ownview = ownview;
+    }
+
+    buffer_info(const buffer_info &) = delete;
+    buffer_info &operator=(const buffer_info &) = delete;
+
+    buffer_info(buffer_info &&other) noexcept { (*this) = std::move(other); }
+
+    buffer_info &operator=(buffer_info &&rhs) noexcept {
+        ptr = rhs.ptr;
+        itemsize = rhs.itemsize;
+        size = rhs.size;
+        format = std::move(rhs.format);
+        ndim = rhs.ndim;
+        shape = std::move(rhs.shape);
+        strides = std::move(rhs.strides);
+        std::swap(m_view, rhs.m_view);
+        std::swap(ownview, rhs.ownview);
+        readonly = rhs.readonly;
+        return *this;
+    }
+
+    ~buffer_info() {
+        if (m_view && ownview) {
+            PyBuffer_Release(m_view);
+            delete m_view;
+        }
+    }
+
+    Py_buffer *view() const { return m_view; }
+    Py_buffer *&view() { return m_view; }
+
+    /* True if the buffer item type is equivalent to `T`. */
+    // To define "equivalent" by example:
+    // `buffer_info::item_type_is_equivalent_to<int>(b)` and
+    // `buffer_info::item_type_is_equivalent_to<long>(b)` may both be true
+    // on some platforms, but `int` and `unsigned` will never be equivalent.
+    // For the ground truth, please inspect `detail::compare_buffer_info<>`.
+    template <typename T>
+    bool item_type_is_equivalent_to() const {
+        return detail::compare_buffer_info<T>::compare(*this);
+    }
+
+private:
+    struct private_ctr_tag {};
+
+    buffer_info(private_ctr_tag,
+                void *ptr,
+                ssize_t itemsize,
+                const std::string &format,
+                ssize_t ndim,
+                detail::any_container<ssize_t> &&shape_in,
+                detail::any_container<ssize_t> &&strides_in,
+                bool readonly)
+        : buffer_info(
+            ptr, itemsize, format, ndim, std::move(shape_in), std::move(strides_in), readonly) {}
+
+    Py_buffer *m_view = nullptr;
+    bool ownview = false;
+};
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+template <typename T, typename SFINAE>
+struct compare_buffer_info {
+    static bool compare(const buffer_info &b) {
+        // NOLINTNEXTLINE(bugprone-sizeof-expression) Needed for `PyObject *`
+        return b.format == format_descriptor<T>::format() && b.itemsize == (ssize_t) sizeof(T);
+    }
+};
+
+template <typename T>
+struct compare_buffer_info<T, detail::enable_if_t<std::is_integral<T>::value>> {
+    static bool compare(const buffer_info &b) {
+        return (size_t) b.itemsize == sizeof(T)
+               && (b.format == format_descriptor<T>::value
+                   || ((sizeof(T) == sizeof(long))
+                       && b.format == (std::is_unsigned<T>::value ? "L" : "l"))
+                   || ((sizeof(T) == sizeof(size_t))
+                       && b.format == (std::is_unsigned<T>::value ? "N" : "n")));
+    }
+};
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/chrono.h

@@ -0,0 +1,225 @@
+/*
+    pybind11/chrono.h: Transparent conversion between std::chrono and python's datetime
+
+    Copyright (c) 2016 Trent Houliston <trent@houliston.me> and
+                       Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+#include <chrono>
+#include <cmath>
+#include <ctime>
+#include <datetime.h>
+#include <mutex>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+template <typename type>
+class duration_caster {
+public:
+    using rep = typename type::rep;
+    using period = typename type::period;
+
+    // signed 25 bits required by the standard.
+    using days = std::chrono::duration<int_least32_t, std::ratio<86400>>;
+
+    bool load(handle src, bool) {
+        using namespace std::chrono;
+
+        // Lazy initialise the PyDateTime import
+        if (!PyDateTimeAPI) {
+            PyDateTime_IMPORT;
+        }
+
+        if (!src) {
+            return false;
+        }
+        // If invoked with datetime.delta object
+        if (PyDelta_Check(src.ptr())) {
+            value = type(duration_cast<duration<rep, period>>(
+                days(PyDateTime_DELTA_GET_DAYS(src.ptr()))
+                + seconds(PyDateTime_DELTA_GET_SECONDS(src.ptr()))
+                + microseconds(PyDateTime_DELTA_GET_MICROSECONDS(src.ptr()))));
+            return true;
+        }
+        // If invoked with a float we assume it is seconds and convert
+        if (PyFloat_Check(src.ptr())) {
+            value = type(duration_cast<duration<rep, period>>(
+                duration<double>(PyFloat_AsDouble(src.ptr()))));
+            return true;
+        }
+        return false;
+    }
+
+    // If this is a duration just return it back
+    static const std::chrono::duration<rep, period> &
+    get_duration(const std::chrono::duration<rep, period> &src) {
+        return src;
+    }
+
+    // If this is a time_point get the time_since_epoch
+    template <typename Clock>
+    static std::chrono::duration<rep, period>
+    get_duration(const std::chrono::time_point<Clock, std::chrono::duration<rep, period>> &src) {
+        return src.time_since_epoch();
+    }
+
+    static handle cast(const type &src, return_value_policy /* policy */, handle /* parent */) {
+        using namespace std::chrono;
+
+        // Use overloaded function to get our duration from our source
+        // Works out if it is a duration or time_point and get the duration
+        auto d = get_duration(src);
+
+        // Lazy initialise the PyDateTime import
+        if (!PyDateTimeAPI) {
+            PyDateTime_IMPORT;
+        }
+
+        // Declare these special duration types so the conversions happen with the correct
+        // primitive types (int)
+        using dd_t = duration<int, std::ratio<86400>>;
+        using ss_t = duration<int, std::ratio<1>>;
+        using us_t = duration<int, std::micro>;
+
+        auto dd = duration_cast<dd_t>(d);
+        auto subd = d - dd;
+        auto ss = duration_cast<ss_t>(subd);
+        auto us = duration_cast<us_t>(subd - ss);
+        return PyDelta_FromDSU(dd.count(), ss.count(), us.count());
+    }
+
+    PYBIND11_TYPE_CASTER(type, const_name("datetime.timedelta"));
+};
+
+inline std::tm *localtime_thread_safe(const std::time_t *time, std::tm *buf) {
+#if (defined(__STDC_LIB_EXT1__) && defined(__STDC_WANT_LIB_EXT1__)) || defined(_MSC_VER)
+    if (localtime_s(buf, time))
+        return nullptr;
+    return buf;
+#else
+    static std::mutex mtx;
+    std::lock_guard<std::mutex> lock(mtx);
+    std::tm *tm_ptr = std::localtime(time);
+    if (tm_ptr != nullptr) {
+        *buf = *tm_ptr;
+    }
+    return tm_ptr;
+#endif
+}
+
+// This is for casting times on the system clock into datetime.datetime instances
+template <typename Duration>
+class type_caster<std::chrono::time_point<std::chrono::system_clock, Duration>> {
+public:
+    using type = std::chrono::time_point<std::chrono::system_clock, Duration>;
+    bool load(handle src, bool) {
+        using namespace std::chrono;
+
+        // Lazy initialise the PyDateTime import
+        if (!PyDateTimeAPI) {
+            PyDateTime_IMPORT;
+        }
+
+        if (!src) {
+            return false;
+        }
+
+        std::tm cal;
+        microseconds msecs;
+
+        if (PyDateTime_Check(src.ptr())) {
+            cal.tm_sec = PyDateTime_DATE_GET_SECOND(src.ptr());
+            cal.tm_min = PyDateTime_DATE_GET_MINUTE(src.ptr());
+            cal.tm_hour = PyDateTime_DATE_GET_HOUR(src.ptr());
+            cal.tm_mday = PyDateTime_GET_DAY(src.ptr());
+            cal.tm_mon = PyDateTime_GET_MONTH(src.ptr()) - 1;
+            cal.tm_year = PyDateTime_GET_YEAR(src.ptr()) - 1900;
+            cal.tm_isdst = -1;
+            msecs = microseconds(PyDateTime_DATE_GET_MICROSECOND(src.ptr()));
+        } else if (PyDate_Check(src.ptr())) {
+            cal.tm_sec = 0;
+            cal.tm_min = 0;
+            cal.tm_hour = 0;
+            cal.tm_mday = PyDateTime_GET_DAY(src.ptr());
+            cal.tm_mon = PyDateTime_GET_MONTH(src.ptr()) - 1;
+            cal.tm_year = PyDateTime_GET_YEAR(src.ptr()) - 1900;
+            cal.tm_isdst = -1;
+            msecs = microseconds(0);
+        } else if (PyTime_Check(src.ptr())) {
+            cal.tm_sec = PyDateTime_TIME_GET_SECOND(src.ptr());
+            cal.tm_min = PyDateTime_TIME_GET_MINUTE(src.ptr());
+            cal.tm_hour = PyDateTime_TIME_GET_HOUR(src.ptr());
+            cal.tm_mday = 1;  // This date (day, month, year) = (1, 0, 70)
+            cal.tm_mon = 0;   // represents 1-Jan-1970, which is the first
+            cal.tm_year = 70; // earliest available date for Python's datetime
+            cal.tm_isdst = -1;
+            msecs = microseconds(PyDateTime_TIME_GET_MICROSECOND(src.ptr()));
+        } else {
+            return false;
+        }
+
+        value = time_point_cast<Duration>(system_clock::from_time_t(std::mktime(&cal)) + msecs);
+        return true;
+    }
+
+    static handle cast(const std::chrono::time_point<std::chrono::system_clock, Duration> &src,
+                       return_value_policy /* policy */,
+                       handle /* parent */) {
+        using namespace std::chrono;
+
+        // Lazy initialise the PyDateTime import
+        if (!PyDateTimeAPI) {
+            PyDateTime_IMPORT;
+        }
+
+        // Get out microseconds, and make sure they are positive, to avoid bug in eastern
+        // hemisphere time zones (cfr. https://github.com/pybind/pybind11/issues/2417)
+        using us_t = duration<int, std::micro>;
+        auto us = duration_cast<us_t>(src.time_since_epoch() % seconds(1));
+        if (us.count() < 0) {
+            us += seconds(1);
+        }
+
+        // Subtract microseconds BEFORE `system_clock::to_time_t`, because:
+        // > If std::time_t has lower precision, it is implementation-defined whether the value is
+        // rounded or truncated. (https://en.cppreference.com/w/cpp/chrono/system_clock/to_time_t)
+        std::time_t tt
+            = system_clock::to_time_t(time_point_cast<system_clock::duration>(src - us));
+
+        std::tm localtime;
+        std::tm *localtime_ptr = localtime_thread_safe(&tt, &localtime);
+        if (!localtime_ptr) {
+            throw cast_error("Unable to represent system_clock in local time");
+        }
+        return PyDateTime_FromDateAndTime(localtime.tm_year + 1900,
+                                          localtime.tm_mon + 1,
+                                          localtime.tm_mday,
+                                          localtime.tm_hour,
+                                          localtime.tm_min,
+                                          localtime.tm_sec,
+                                          us.count());
+    }
+    PYBIND11_TYPE_CASTER(type, const_name("datetime.datetime"));
+};
+
+// Other clocks that are not the system clock are not measured as datetime.datetime objects
+// since they are not measured on calendar time. So instead we just make them timedeltas
+// Or if they have passed us a time as a float we convert that
+template <typename Clock, typename Duration>
+class type_caster<std::chrono::time_point<Clock, Duration>>
+    : public duration_caster<std::chrono::time_point<Clock, Duration>> {};
+
+template <typename Rep, typename Period>
+class type_caster<std::chrono::duration<Rep, Period>>
+    : public duration_caster<std::chrono::duration<Rep, Period>> {};
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/common.h

@@ -0,0 +1,2 @@
+#include "detail/common.h"
+#warning "Including 'common.h' is deprecated. It will be removed in v3.0. Use 'pybind11.h'."

3rdparty/pybind11/include/pybind11/complex.h

@@ -0,0 +1,74 @@
+/*
+    pybind11/complex.h: Complex number support
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+#include <complex>
+
+/// glibc defines I as a macro which breaks things, e.g., boost template names
+#ifdef I
+#    undef I
+#endif
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+template <typename T>
+struct format_descriptor<std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>> {
+    static constexpr const char c = format_descriptor<T>::c;
+    static constexpr const char value[3] = {'Z', c, '\0'};
+    static std::string format() { return std::string(value); }
+};
+
+#ifndef PYBIND11_CPP17
+
+template <typename T>
+constexpr const char
+    format_descriptor<std::complex<T>,
+                      detail::enable_if_t<std::is_floating_point<T>::value>>::value[3];
+
+#endif
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+template <typename T>
+struct is_fmt_numeric<std::complex<T>, detail::enable_if_t<std::is_floating_point<T>::value>> {
+    static constexpr bool value = true;
+    static constexpr int index = is_fmt_numeric<T>::index + 3;
+};
+
+template <typename T>
+class type_caster<std::complex<T>> {
+public:
+    bool load(handle src, bool convert) {
+        if (!src) {
+            return false;
+        }
+        if (!convert && !PyComplex_Check(src.ptr())) {
+            return false;
+        }
+        Py_complex result = PyComplex_AsCComplex(src.ptr());
+        if (result.real == -1.0 && PyErr_Occurred()) {
+            PyErr_Clear();
+            return false;
+        }
+        value = std::complex<T>((T) result.real, (T) result.imag);
+        return true;
+    }
+
+    static handle
+    cast(const std::complex<T> &src, return_value_policy /* policy */, handle /* parent */) {
+        return PyComplex_FromDoubles((double) src.real(), (double) src.imag());
+    }
+
+    PYBIND11_TYPE_CASTER(std::complex<T>, const_name("complex"));
+};
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/detail/class.h

@@ -0,0 +1,743 @@
+/*
+    pybind11/detail/class.h: Python C API implementation details for py::class_
+
+    Copyright (c) 2017 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "../attr.h"
+#include "../options.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+#if !defined(PYPY_VERSION)
+#    define PYBIND11_BUILTIN_QUALNAME
+#    define PYBIND11_SET_OLDPY_QUALNAME(obj, nameobj)
+#else
+// In PyPy, we still set __qualname__ so that we can produce reliable function type
+// signatures; in CPython this macro expands to nothing:
+#    define PYBIND11_SET_OLDPY_QUALNAME(obj, nameobj)                                             \
+        setattr((PyObject *) obj, "__qualname__", nameobj)
+#endif
+
+inline std::string get_fully_qualified_tp_name(PyTypeObject *type) {
+#if !defined(PYPY_VERSION)
+    return type->tp_name;
+#else
+    auto module_name = handle((PyObject *) type).attr("__module__").cast<std::string>();
+    if (module_name == PYBIND11_BUILTINS_MODULE)
+        return type->tp_name;
+    else
+        return std::move(module_name) + "." + type->tp_name;
+#endif
+}
+
+inline PyTypeObject *type_incref(PyTypeObject *type) {
+    Py_INCREF(type);
+    return type;
+}
+
+#if !defined(PYPY_VERSION)
+
+/// `pybind11_static_property.__get__()`: Always pass the class instead of the instance.
+extern "C" inline PyObject *pybind11_static_get(PyObject *self, PyObject * /*ob*/, PyObject *cls) {
+    return PyProperty_Type.tp_descr_get(self, cls, cls);
+}
+
+/// `pybind11_static_property.__set__()`: Just like the above `__get__()`.
+extern "C" inline int pybind11_static_set(PyObject *self, PyObject *obj, PyObject *value) {
+    PyObject *cls = PyType_Check(obj) ? obj : (PyObject *) Py_TYPE(obj);
+    return PyProperty_Type.tp_descr_set(self, cls, value);
+}
+
+// Forward declaration to use in `make_static_property_type()`
+inline void enable_dynamic_attributes(PyHeapTypeObject *heap_type);
+
+/** A `static_property` is the same as a `property` but the `__get__()` and `__set__()`
+    methods are modified to always use the object type instead of a concrete instance.
+    Return value: New reference. */
+inline PyTypeObject *make_static_property_type() {
+    constexpr auto *name = "pybind11_static_property";
+    auto name_obj = reinterpret_steal<object>(PYBIND11_FROM_STRING(name));
+
+    /* Danger zone: from now (and until PyType_Ready), make sure to
+       issue no Python C API calls which could potentially invoke the
+       garbage collector (the GC will call type_traverse(), which will in
+       turn find the newly constructed type in an invalid state) */
+    auto *heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
+    if (!heap_type) {
+        pybind11_fail("make_static_property_type(): error allocating type!");
+    }
+
+    heap_type->ht_name = name_obj.inc_ref().ptr();
+#    ifdef PYBIND11_BUILTIN_QUALNAME
+    heap_type->ht_qualname = name_obj.inc_ref().ptr();
+#    endif
+
+    auto *type = &heap_type->ht_type;
+    type->tp_name = name;
+    type->tp_base = type_incref(&PyProperty_Type);
+    type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HEAPTYPE;
+    type->tp_descr_get = pybind11_static_get;
+    type->tp_descr_set = pybind11_static_set;
+
+    if (PyType_Ready(type) < 0) {
+        pybind11_fail("make_static_property_type(): failure in PyType_Ready()!");
+    }
+
+#    if PY_VERSION_HEX >= 0x030C0000
+    // PRE 3.12 FEATURE FREEZE. PLEASE REVIEW AFTER FREEZE.
+    // Since Python-3.12 property-derived types are required to
+    // have dynamic attributes (to set `__doc__`)
+    enable_dynamic_attributes(heap_type);
+#    endif
+
+    setattr((PyObject *) type, "__module__", str("pybind11_builtins"));
+    PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
+
+    return type;
+}
+
+#else // PYPY
+
+/** PyPy has some issues with the above C API, so we evaluate Python code instead.
+    This function will only be called once so performance isn't really a concern.
+    Return value: New reference. */
+inline PyTypeObject *make_static_property_type() {
+    auto d = dict();
+    PyObject *result = PyRun_String(R"(\
+class pybind11_static_property(property):
+    def __get__(self, obj, cls):
+        return property.__get__(self, cls, cls)
+
+    def __set__(self, obj, value):
+        cls = obj if isinstance(obj, type) else type(obj)
+        property.__set__(self, cls, value)
+)",
+                                    Py_file_input,
+                                    d.ptr(),
+                                    d.ptr());
+    if (result == nullptr)
+        throw error_already_set();
+    Py_DECREF(result);
+    return (PyTypeObject *) d["pybind11_static_property"].cast<object>().release().ptr();
+}
+
+#endif // PYPY
+
+/** Types with static properties need to handle `Type.static_prop = x` in a specific way.
+    By default, Python replaces the `static_property` itself, but for wrapped C++ types
+    we need to call `static_property.__set__()` in order to propagate the new value to
+    the underlying C++ data structure. */
+extern "C" inline int pybind11_meta_setattro(PyObject *obj, PyObject *name, PyObject *value) {
+    // Use `_PyType_Lookup()` instead of `PyObject_GetAttr()` in order to get the raw
+    // descriptor (`property`) instead of calling `tp_descr_get` (`property.__get__()`).
+    PyObject *descr = _PyType_Lookup((PyTypeObject *) obj, name);
+
+    // The following assignment combinations are possible:
+    //   1. `Type.static_prop = value`             --> descr_set: `Type.static_prop.__set__(value)`
+    //   2. `Type.static_prop = other_static_prop` --> setattro:  replace existing `static_prop`
+    //   3. `Type.regular_attribute = value`       --> setattro:  regular attribute assignment
+    auto *const static_prop = (PyObject *) get_internals().static_property_type;
+    const auto call_descr_set = (descr != nullptr) && (value != nullptr)
+                                && (PyObject_IsInstance(descr, static_prop) != 0)
+                                && (PyObject_IsInstance(value, static_prop) == 0);
+    if (call_descr_set) {
+        // Call `static_property.__set__()` instead of replacing the `static_property`.
+#if !defined(PYPY_VERSION)
+        return Py_TYPE(descr)->tp_descr_set(descr, obj, value);
+#else
+        if (PyObject *result = PyObject_CallMethod(descr, "__set__", "OO", obj, value)) {
+            Py_DECREF(result);
+            return 0;
+        } else {
+            return -1;
+        }
+#endif
+    } else {
+        // Replace existing attribute.
+        return PyType_Type.tp_setattro(obj, name, value);
+    }
+}
+
+/**
+ * Python 3's PyInstanceMethod_Type hides itself via its tp_descr_get, which prevents aliasing
+ * methods via cls.attr("m2") = cls.attr("m1"): instead the tp_descr_get returns a plain function,
+ * when called on a class, or a PyMethod, when called on an instance.  Override that behaviour here
+ * to do a special case bypass for PyInstanceMethod_Types.
+ */
+extern "C" inline PyObject *pybind11_meta_getattro(PyObject *obj, PyObject *name) {
+    PyObject *descr = _PyType_Lookup((PyTypeObject *) obj, name);
+    if (descr && PyInstanceMethod_Check(descr)) {
+        Py_INCREF(descr);
+        return descr;
+    }
+    return PyType_Type.tp_getattro(obj, name);
+}
+
+/// metaclass `__call__` function that is used to create all pybind11 objects.
+extern "C" inline PyObject *pybind11_meta_call(PyObject *type, PyObject *args, PyObject *kwargs) {
+
+    // use the default metaclass call to create/initialize the object
+    PyObject *self = PyType_Type.tp_call(type, args, kwargs);
+    if (self == nullptr) {
+        return nullptr;
+    }
+
+    // This must be a pybind11 instance
+    auto *instance = reinterpret_cast<detail::instance *>(self);
+
+    // Ensure that the base __init__ function(s) were called
+    for (const auto &vh : values_and_holders(instance)) {
+        if (!vh.holder_constructed()) {
+            PyErr_Format(PyExc_TypeError,
+                         "%.200s.__init__() must be called when overriding __init__",
+                         get_fully_qualified_tp_name(vh.type->type).c_str());
+            Py_DECREF(self);
+            return nullptr;
+        }
+    }
+
+    return self;
+}
+
+/// Cleanup the type-info for a pybind11-registered type.
+extern "C" inline void pybind11_meta_dealloc(PyObject *obj) {
+    auto *type = (PyTypeObject *) obj;
+    auto &internals = get_internals();
+
+    // A pybind11-registered type will:
+    // 1) be found in internals.registered_types_py
+    // 2) have exactly one associated `detail::type_info`
+    auto found_type = internals.registered_types_py.find(type);
+    if (found_type != internals.registered_types_py.end() && found_type->second.size() == 1
+        && found_type->second[0]->type == type) {
+
+        auto *tinfo = found_type->second[0];
+        auto tindex = std::type_index(*tinfo->cpptype);
+        internals.direct_conversions.erase(tindex);
+
+        if (tinfo->module_local) {
+            get_local_internals().registered_types_cpp.erase(tindex);
+        } else {
+            internals.registered_types_cpp.erase(tindex);
+        }
+        internals.registered_types_py.erase(tinfo->type);
+
+        // Actually just `std::erase_if`, but that's only available in C++20
+        auto &cache = internals.inactive_override_cache;
+        for (auto it = cache.begin(), last = cache.end(); it != last;) {
+            if (it->first == (PyObject *) tinfo->type) {
+                it = cache.erase(it);
+            } else {
+                ++it;
+            }
+        }
+
+        delete tinfo;
+    }
+
+    PyType_Type.tp_dealloc(obj);
+}
+
+/** This metaclass is assigned by default to all pybind11 types and is required in order
+    for static properties to function correctly. Users may override this using `py::metaclass`.
+    Return value: New reference. */
+inline PyTypeObject *make_default_metaclass() {
+    constexpr auto *name = "pybind11_type";
+    auto name_obj = reinterpret_steal<object>(PYBIND11_FROM_STRING(name));
+
+    /* Danger zone: from now (and until PyType_Ready), make sure to
+       issue no Python C API calls which could potentially invoke the
+       garbage collector (the GC will call type_traverse(), which will in
+       turn find the newly constructed type in an invalid state) */
+    auto *heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
+    if (!heap_type) {
+        pybind11_fail("make_default_metaclass(): error allocating metaclass!");
+    }
+
+    heap_type->ht_name = name_obj.inc_ref().ptr();
+#ifdef PYBIND11_BUILTIN_QUALNAME
+    heap_type->ht_qualname = name_obj.inc_ref().ptr();
+#endif
+
+    auto *type = &heap_type->ht_type;
+    type->tp_name = name;
+    type->tp_base = type_incref(&PyType_Type);
+    type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HEAPTYPE;
+
+    type->tp_call = pybind11_meta_call;
+
+    type->tp_setattro = pybind11_meta_setattro;
+    type->tp_getattro = pybind11_meta_getattro;
+
+    type->tp_dealloc = pybind11_meta_dealloc;
+
+    if (PyType_Ready(type) < 0) {
+        pybind11_fail("make_default_metaclass(): failure in PyType_Ready()!");
+    }
+
+    setattr((PyObject *) type, "__module__", str("pybind11_builtins"));
+    PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
+
+    return type;
+}
+
+/// For multiple inheritance types we need to recursively register/deregister base pointers for any
+/// base classes with pointers that are difference from the instance value pointer so that we can
+/// correctly recognize an offset base class pointer. This calls a function with any offset base
+/// ptrs.
+inline void traverse_offset_bases(void *valueptr,
+                                  const detail::type_info *tinfo,
+                                  instance *self,
+                                  bool (*f)(void * /*parentptr*/, instance * /*self*/)) {
+    for (handle h : reinterpret_borrow<tuple>(tinfo->type->tp_bases)) {
+        if (auto *parent_tinfo = get_type_info((PyTypeObject *) h.ptr())) {
+            for (auto &c : parent_tinfo->implicit_casts) {
+                if (c.first == tinfo->cpptype) {
+                    auto *parentptr = c.second(valueptr);
+                    if (parentptr != valueptr) {
+                        f(parentptr, self);
+                    }
+                    traverse_offset_bases(parentptr, parent_tinfo, self, f);
+                    break;
+                }
+            }
+        }
+    }
+}
+
+inline bool register_instance_impl(void *ptr, instance *self) {
+    get_internals().registered_instances.emplace(ptr, self);
+    return true; // unused, but gives the same signature as the deregister func
+}
+inline bool deregister_instance_impl(void *ptr, instance *self) {
+    auto &registered_instances = get_internals().registered_instances;
+    auto range = registered_instances.equal_range(ptr);
+    for (auto it = range.first; it != range.second; ++it) {
+        if (self == it->second) {
+            registered_instances.erase(it);
+            return true;
+        }
+    }
+    return false;
+}
+
+inline void register_instance(instance *self, void *valptr, const type_info *tinfo) {
+    register_instance_impl(valptr, self);
+    if (!tinfo->simple_ancestors) {
+        traverse_offset_bases(valptr, tinfo, self, register_instance_impl);
+    }
+}
+
+inline bool deregister_instance(instance *self, void *valptr, const type_info *tinfo) {
+    bool ret = deregister_instance_impl(valptr, self);
+    if (!tinfo->simple_ancestors) {
+        traverse_offset_bases(valptr, tinfo, self, deregister_instance_impl);
+    }
+    return ret;
+}
+
+/// Instance creation function for all pybind11 types. It allocates the internal instance layout
+/// for holding C++ objects and holders.  Allocation is done lazily (the first time the instance is
+/// cast to a reference or pointer), and initialization is done by an `__init__` function.
+inline PyObject *make_new_instance(PyTypeObject *type) {
+#if defined(PYPY_VERSION)
+    // PyPy gets tp_basicsize wrong (issue 2482) under multiple inheritance when the first
+    // inherited object is a plain Python type (i.e. not derived from an extension type).  Fix it.
+    ssize_t instance_size = static_cast<ssize_t>(sizeof(instance));
+    if (type->tp_basicsize < instance_size) {
+        type->tp_basicsize = instance_size;
+    }
+#endif
+    PyObject *self = type->tp_alloc(type, 0);
+    auto *inst = reinterpret_cast<instance *>(self);
+    // Allocate the value/holder internals:
+    inst->allocate_layout();
+
+    return self;
+}
+
+/// Instance creation function for all pybind11 types. It only allocates space for the
+/// C++ object, but doesn't call the constructor -- an `__init__` function must do that.
+extern "C" inline PyObject *pybind11_object_new(PyTypeObject *type, PyObject *, PyObject *) {
+    return make_new_instance(type);
+}
+
+/// An `__init__` function constructs the C++ object. Users should provide at least one
+/// of these using `py::init` or directly with `.def(__init__, ...)`. Otherwise, the
+/// following default function will be used which simply throws an exception.
+extern "C" inline int pybind11_object_init(PyObject *self, PyObject *, PyObject *) {
+    PyTypeObject *type = Py_TYPE(self);
+    std::string msg = get_fully_qualified_tp_name(type) + ": No constructor defined!";
+    PyErr_SetString(PyExc_TypeError, msg.c_str());
+    return -1;
+}
+
+inline void add_patient(PyObject *nurse, PyObject *patient) {
+    auto &internals = get_internals();
+    auto *instance = reinterpret_cast<detail::instance *>(nurse);
+    instance->has_patients = true;
+    Py_INCREF(patient);
+    internals.patients[nurse].push_back(patient);
+}
+
+inline void clear_patients(PyObject *self) {
+    auto *instance = reinterpret_cast<detail::instance *>(self);
+    auto &internals = get_internals();
+    auto pos = internals.patients.find(self);
+    assert(pos != internals.patients.end());
+    // Clearing the patients can cause more Python code to run, which
+    // can invalidate the iterator. Extract the vector of patients
+    // from the unordered_map first.
+    auto patients = std::move(pos->second);
+    internals.patients.erase(pos);
+    instance->has_patients = false;
+    for (PyObject *&patient : patients) {
+        Py_CLEAR(patient);
+    }
+}
+
+/// Clears all internal data from the instance and removes it from registered instances in
+/// preparation for deallocation.
+inline void clear_instance(PyObject *self) {
+    auto *instance = reinterpret_cast<detail::instance *>(self);
+
+    // Deallocate any values/holders, if present:
+    for (auto &v_h : values_and_holders(instance)) {
+        if (v_h) {
+
+            // We have to deregister before we call dealloc because, for virtual MI types, we still
+            // need to be able to get the parent pointers.
+            if (v_h.instance_registered()
+                && !deregister_instance(instance, v_h.value_ptr(), v_h.type)) {
+                pybind11_fail(
+                    "pybind11_object_dealloc(): Tried to deallocate unregistered instance!");
+            }
+
+            if (instance->owned || v_h.holder_constructed()) {
+                v_h.type->dealloc(v_h);
+            }
+        }
+    }
+    // Deallocate the value/holder layout internals:
+    instance->deallocate_layout();
+
+    if (instance->weakrefs) {
+        PyObject_ClearWeakRefs(self);
+    }
+
+    PyObject **dict_ptr = _PyObject_GetDictPtr(self);
+    if (dict_ptr) {
+        Py_CLEAR(*dict_ptr);
+    }
+
+    if (instance->has_patients) {
+        clear_patients(self);
+    }
+}
+
+/// Instance destructor function for all pybind11 types. It calls `type_info.dealloc`
+/// to destroy the C++ object itself, while the rest is Python bookkeeping.
+extern "C" inline void pybind11_object_dealloc(PyObject *self) {
+    auto *type = Py_TYPE(self);
+
+    // If this is a GC tracked object, untrack it first
+    // Note that the track call is implicitly done by the
+    // default tp_alloc, which we never override.
+    if (PyType_HasFeature(type, Py_TPFLAGS_HAVE_GC) != 0) {
+        PyObject_GC_UnTrack(self);
+    }
+
+    clear_instance(self);
+
+    type->tp_free(self);
+
+#if PY_VERSION_HEX < 0x03080000
+    // `type->tp_dealloc != pybind11_object_dealloc` means that we're being called
+    // as part of a derived type's dealloc, in which case we're not allowed to decref
+    // the type here. For cross-module compatibility, we shouldn't compare directly
+    // with `pybind11_object_dealloc`, but with the common one stashed in internals.
+    auto pybind11_object_type = (PyTypeObject *) get_internals().instance_base;
+    if (type->tp_dealloc == pybind11_object_type->tp_dealloc)
+        Py_DECREF(type);
+#else
+    // This was not needed before Python 3.8 (Python issue 35810)
+    // https://github.com/pybind/pybind11/issues/1946
+    Py_DECREF(type);
+#endif
+}
+
+std::string error_string();
+
+/** Create the type which can be used as a common base for all classes.  This is
+    needed in order to satisfy Python's requirements for multiple inheritance.
+    Return value: New reference. */
+inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
+    constexpr auto *name = "pybind11_object";
+    auto name_obj = reinterpret_steal<object>(PYBIND11_FROM_STRING(name));
+
+    /* Danger zone: from now (and until PyType_Ready), make sure to
+       issue no Python C API calls which could potentially invoke the
+       garbage collector (the GC will call type_traverse(), which will in
+       turn find the newly constructed type in an invalid state) */
+    auto *heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
+    if (!heap_type) {
+        pybind11_fail("make_object_base_type(): error allocating type!");
+    }
+
+    heap_type->ht_name = name_obj.inc_ref().ptr();
+#ifdef PYBIND11_BUILTIN_QUALNAME
+    heap_type->ht_qualname = name_obj.inc_ref().ptr();
+#endif
+
+    auto *type = &heap_type->ht_type;
+    type->tp_name = name;
+    type->tp_base = type_incref(&PyBaseObject_Type);
+    type->tp_basicsize = static_cast<ssize_t>(sizeof(instance));
+    type->tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HEAPTYPE;
+
+    type->tp_new = pybind11_object_new;
+    type->tp_init = pybind11_object_init;
+    type->tp_dealloc = pybind11_object_dealloc;
+
+    /* Support weak references (needed for the keep_alive feature) */
+    type->tp_weaklistoffset = offsetof(instance, weakrefs);
+
+    if (PyType_Ready(type) < 0) {
+        pybind11_fail("PyType_Ready failed in make_object_base_type(): " + error_string());
+    }
+
+    setattr((PyObject *) type, "__module__", str("pybind11_builtins"));
+    PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
+
+    assert(!PyType_HasFeature(type, Py_TPFLAGS_HAVE_GC));
+    return (PyObject *) heap_type;
+}
+
+/// dynamic_attr: Allow the garbage collector to traverse the internal instance `__dict__`.
+extern "C" inline int pybind11_traverse(PyObject *self, visitproc visit, void *arg) {
+    PyObject *&dict = *_PyObject_GetDictPtr(self);
+    Py_VISIT(dict);
+// https://docs.python.org/3/c-api/typeobj.html#c.PyTypeObject.tp_traverse
+#if PY_VERSION_HEX >= 0x03090000
+    Py_VISIT(Py_TYPE(self));
+#endif
+    return 0;
+}
+
+/// dynamic_attr: Allow the GC to clear the dictionary.
+extern "C" inline int pybind11_clear(PyObject *self) {
+    PyObject *&dict = *_PyObject_GetDictPtr(self);
+    Py_CLEAR(dict);
+    return 0;
+}
+
+/// Give instances of this type a `__dict__` and opt into garbage collection.
+inline void enable_dynamic_attributes(PyHeapTypeObject *heap_type) {
+    auto *type = &heap_type->ht_type;
+    type->tp_flags |= Py_TPFLAGS_HAVE_GC;
+#if PY_VERSION_HEX < 0x030B0000
+    type->tp_dictoffset = type->tp_basicsize;           // place dict at the end
+    type->tp_basicsize += (ssize_t) sizeof(PyObject *); // and allocate enough space for it
+#else
+    type->tp_flags |= Py_TPFLAGS_MANAGED_DICT;
+#endif
+    type->tp_traverse = pybind11_traverse;
+    type->tp_clear = pybind11_clear;
+
+    static PyGetSetDef getset[] = {{
+#if PY_VERSION_HEX < 0x03070000
+                                       const_cast<char *>("__dict__"),
+#else
+                                       "__dict__",
+#endif
+                                       PyObject_GenericGetDict,
+                                       PyObject_GenericSetDict,
+                                       nullptr,
+                                       nullptr},
+                                   {nullptr, nullptr, nullptr, nullptr, nullptr}};
+    type->tp_getset = getset;
+}
+
+/// buffer_protocol: Fill in the view as specified by flags.
+extern "C" inline int pybind11_getbuffer(PyObject *obj, Py_buffer *view, int flags) {
+    // Look for a `get_buffer` implementation in this type's info or any bases (following MRO).
+    type_info *tinfo = nullptr;
+    for (auto type : reinterpret_borrow<tuple>(Py_TYPE(obj)->tp_mro)) {
+        tinfo = get_type_info((PyTypeObject *) type.ptr());
+        if (tinfo && tinfo->get_buffer) {
+            break;
+        }
+    }
+    if (view == nullptr || !tinfo || !tinfo->get_buffer) {
+        if (view) {
+            view->obj = nullptr;
+        }
+        PyErr_SetString(PyExc_BufferError, "pybind11_getbuffer(): Internal error");
+        return -1;
+    }
+    std::memset(view, 0, sizeof(Py_buffer));
+    buffer_info *info = tinfo->get_buffer(obj, tinfo->get_buffer_data);
+    if ((flags & PyBUF_WRITABLE) == PyBUF_WRITABLE && info->readonly) {
+        delete info;
+        // view->obj = nullptr;  // Was just memset to 0, so not necessary
+        PyErr_SetString(PyExc_BufferError, "Writable buffer requested for readonly storage");
+        return -1;
+    }
+    view->obj = obj;
+    view->ndim = 1;
+    view->internal = info;
+    view->buf = info->ptr;
+    view->itemsize = info->itemsize;
+    view->len = view->itemsize;
+    for (auto s : info->shape) {
+        view->len *= s;
+    }
+    view->readonly = static_cast<int>(info->readonly);
+    if ((flags & PyBUF_FORMAT) == PyBUF_FORMAT) {
+        view->format = const_cast<char *>(info->format.c_str());
+    }
+    if ((flags & PyBUF_STRIDES) == PyBUF_STRIDES) {
+        view->ndim = (int) info->ndim;
+        view->strides = info->strides.data();
+        view->shape = info->shape.data();
+    }
+    Py_INCREF(view->obj);
+    return 0;
+}
+
+/// buffer_protocol: Release the resources of the buffer.
+extern "C" inline void pybind11_releasebuffer(PyObject *, Py_buffer *view) {
+    delete (buffer_info *) view->internal;
+}
+
+/// Give this type a buffer interface.
+inline void enable_buffer_protocol(PyHeapTypeObject *heap_type) {
+    heap_type->ht_type.tp_as_buffer = &heap_type->as_buffer;
+
+    heap_type->as_buffer.bf_getbuffer = pybind11_getbuffer;
+    heap_type->as_buffer.bf_releasebuffer = pybind11_releasebuffer;
+}
+
+/** Create a brand new Python type according to the `type_record` specification.
+    Return value: New reference. */
+inline PyObject *make_new_python_type(const type_record &rec) {
+    auto name = reinterpret_steal<object>(PYBIND11_FROM_STRING(rec.name));
+
+    auto qualname = name;
+    if (rec.scope && !PyModule_Check(rec.scope.ptr()) && hasattr(rec.scope, "__qualname__")) {
+        qualname = reinterpret_steal<object>(
+            PyUnicode_FromFormat("%U.%U", rec.scope.attr("__qualname__").ptr(), name.ptr()));
+    }
+
+    object module_;
+    if (rec.scope) {
+        if (hasattr(rec.scope, "__module__")) {
+            module_ = rec.scope.attr("__module__");
+        } else if (hasattr(rec.scope, "__name__")) {
+            module_ = rec.scope.attr("__name__");
+        }
+    }
+
+    const auto *full_name = c_str(
+#if !defined(PYPY_VERSION)
+        module_ ? str(module_).cast<std::string>() + "." + rec.name :
+#endif
+                rec.name);
+
+    char *tp_doc = nullptr;
+    if (rec.doc && options::show_user_defined_docstrings()) {
+        /* Allocate memory for docstring (using PyObject_MALLOC, since
+           Python will free this later on) */
+        size_t size = std::strlen(rec.doc) + 1;
+        tp_doc = (char *) PyObject_MALLOC(size);
+        std::memcpy((void *) tp_doc, rec.doc, size);
+    }
+
+    auto &internals = get_internals();
+    auto bases = tuple(rec.bases);
+    auto *base = (bases.empty()) ? internals.instance_base : bases[0].ptr();
+
+    /* Danger zone: from now (and until PyType_Ready), make sure to
+       issue no Python C API calls which could potentially invoke the
+       garbage collector (the GC will call type_traverse(), which will in
+       turn find the newly constructed type in an invalid state) */
+    auto *metaclass
+        = rec.metaclass.ptr() ? (PyTypeObject *) rec.metaclass.ptr() : internals.default_metaclass;
+
+    auto *heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
+    if (!heap_type) {
+        pybind11_fail(std::string(rec.name) + ": Unable to create type object!");
+    }
+
+    heap_type->ht_name = name.release().ptr();
+#ifdef PYBIND11_BUILTIN_QUALNAME
+    heap_type->ht_qualname = qualname.inc_ref().ptr();
+#endif
+
+    auto *type = &heap_type->ht_type;
+    type->tp_name = full_name;
+    type->tp_doc = tp_doc;
+    type->tp_base = type_incref((PyTypeObject *) base);
+    type->tp_basicsize = static_cast<ssize_t>(sizeof(instance));
+    if (!bases.empty()) {
+        type->tp_bases = bases.release().ptr();
+    }
+
+    /* Don't inherit base __init__ */
+    type->tp_init = pybind11_object_init;
+
+    /* Supported protocols */
+    type->tp_as_number = &heap_type->as_number;
+    type->tp_as_sequence = &heap_type->as_sequence;
+    type->tp_as_mapping = &heap_type->as_mapping;
+    type->tp_as_async = &heap_type->as_async;
+
+    /* Flags */
+    type->tp_flags |= Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HEAPTYPE;
+    if (!rec.is_final) {
+        type->tp_flags |= Py_TPFLAGS_BASETYPE;
+    }
+
+    if (rec.dynamic_attr) {
+        enable_dynamic_attributes(heap_type);
+    }
+
+    if (rec.buffer_protocol) {
+        enable_buffer_protocol(heap_type);
+    }
+
+    if (rec.custom_type_setup_callback) {
+        rec.custom_type_setup_callback(heap_type);
+    }
+
+    if (PyType_Ready(type) < 0) {
+        pybind11_fail(std::string(rec.name) + ": PyType_Ready failed: " + error_string());
+    }
+
+    assert(!rec.dynamic_attr || PyType_HasFeature(type, Py_TPFLAGS_HAVE_GC));
+
+    /* Register type with the parent scope */
+    if (rec.scope) {
+        setattr(rec.scope, rec.name, (PyObject *) type);
+    } else {
+        Py_INCREF(type); // Keep it alive forever (reference leak)
+    }
+
+    if (module_) { // Needed by pydoc
+        setattr((PyObject *) type, "__module__", module_);
+    }
+
+    PYBIND11_SET_OLDPY_QUALNAME(type, qualname);
+
+    return (PyObject *) type;
+}
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/detail/descr.h

@@ -0,0 +1,171 @@
+/*
+    pybind11/detail/descr.h: Helper type for concatenating type signatures at compile time
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "common.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+#if !defined(_MSC_VER)
+#    define PYBIND11_DESCR_CONSTEXPR static constexpr
+#else
+#    define PYBIND11_DESCR_CONSTEXPR const
+#endif
+
+/* Concatenate type signatures at compile time */
+template <size_t N, typename... Ts>
+struct descr {
+    char text[N + 1]{'\0'};
+
+    constexpr descr() = default;
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    constexpr descr(char const (&s)[N + 1]) : descr(s, make_index_sequence<N>()) {}
+
+    template <size_t... Is>
+    constexpr descr(char const (&s)[N + 1], index_sequence<Is...>) : text{s[Is]..., '\0'} {}
+
+    template <typename... Chars>
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    constexpr descr(char c, Chars... cs) : text{c, static_cast<char>(cs)..., '\0'} {}
+
+    static constexpr std::array<const std::type_info *, sizeof...(Ts) + 1> types() {
+        return {{&typeid(Ts)..., nullptr}};
+    }
+};
+
+template <size_t N1, size_t N2, typename... Ts1, typename... Ts2, size_t... Is1, size_t... Is2>
+constexpr descr<N1 + N2, Ts1..., Ts2...> plus_impl(const descr<N1, Ts1...> &a,
+                                                   const descr<N2, Ts2...> &b,
+                                                   index_sequence<Is1...>,
+                                                   index_sequence<Is2...>) {
+    PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(b);
+    return {a.text[Is1]..., b.text[Is2]...};
+}
+
+template <size_t N1, size_t N2, typename... Ts1, typename... Ts2>
+constexpr descr<N1 + N2, Ts1..., Ts2...> operator+(const descr<N1, Ts1...> &a,
+                                                   const descr<N2, Ts2...> &b) {
+    return plus_impl(a, b, make_index_sequence<N1>(), make_index_sequence<N2>());
+}
+
+template <size_t N>
+constexpr descr<N - 1> const_name(char const (&text)[N]) {
+    return descr<N - 1>(text);
+}
+constexpr descr<0> const_name(char const (&)[1]) { return {}; }
+
+template <size_t Rem, size_t... Digits>
+struct int_to_str : int_to_str<Rem / 10, Rem % 10, Digits...> {};
+template <size_t... Digits>
+struct int_to_str<0, Digits...> {
+    // WARNING: This only works with C++17 or higher.
+    static constexpr auto digits = descr<sizeof...(Digits)>(('0' + Digits)...);
+};
+
+// Ternary description (like std::conditional)
+template <bool B, size_t N1, size_t N2>
+constexpr enable_if_t<B, descr<N1 - 1>> const_name(char const (&text1)[N1], char const (&)[N2]) {
+    return const_name(text1);
+}
+template <bool B, size_t N1, size_t N2>
+constexpr enable_if_t<!B, descr<N2 - 1>> const_name(char const (&)[N1], char const (&text2)[N2]) {
+    return const_name(text2);
+}
+
+template <bool B, typename T1, typename T2>
+constexpr enable_if_t<B, T1> const_name(const T1 &d, const T2 &) {
+    return d;
+}
+template <bool B, typename T1, typename T2>
+constexpr enable_if_t<!B, T2> const_name(const T1 &, const T2 &d) {
+    return d;
+}
+
+template <size_t Size>
+auto constexpr const_name() -> remove_cv_t<decltype(int_to_str<Size / 10, Size % 10>::digits)> {
+    return int_to_str<Size / 10, Size % 10>::digits;
+}
+
+template <typename Type>
+constexpr descr<1, Type> const_name() {
+    return {'%'};
+}
+
+// If "_" is defined as a macro, py::detail::_ cannot be provided.
+// It is therefore best to use py::detail::const_name universally.
+// This block is for backward compatibility only.
+// (The const_name code is repeated to avoid introducing a "_" #define ourselves.)
+#ifndef _
+#    define PYBIND11_DETAIL_UNDERSCORE_BACKWARD_COMPATIBILITY
+template <size_t N>
+constexpr descr<N - 1> _(char const (&text)[N]) {
+    return const_name<N>(text);
+}
+template <bool B, size_t N1, size_t N2>
+constexpr enable_if_t<B, descr<N1 - 1>> _(char const (&text1)[N1], char const (&text2)[N2]) {
+    return const_name<B, N1, N2>(text1, text2);
+}
+template <bool B, size_t N1, size_t N2>
+constexpr enable_if_t<!B, descr<N2 - 1>> _(char const (&text1)[N1], char const (&text2)[N2]) {
+    return const_name<B, N1, N2>(text1, text2);
+}
+template <bool B, typename T1, typename T2>
+constexpr enable_if_t<B, T1> _(const T1 &d1, const T2 &d2) {
+    return const_name<B, T1, T2>(d1, d2);
+}
+template <bool B, typename T1, typename T2>
+constexpr enable_if_t<!B, T2> _(const T1 &d1, const T2 &d2) {
+    return const_name<B, T1, T2>(d1, d2);
+}
+
+template <size_t Size>
+auto constexpr _() -> remove_cv_t<decltype(int_to_str<Size / 10, Size % 10>::digits)> {
+    return const_name<Size>();
+}
+template <typename Type>
+constexpr descr<1, Type> _() {
+    return const_name<Type>();
+}
+#endif // #ifndef _
+
+constexpr descr<0> concat() { return {}; }
+
+template <size_t N, typename... Ts>
+constexpr descr<N, Ts...> concat(const descr<N, Ts...> &descr) {
+    return descr;
+}
+
+#ifdef __cpp_fold_expressions
+template <size_t N1, size_t N2, typename... Ts1, typename... Ts2>
+constexpr descr<N1 + N2 + 2, Ts1..., Ts2...> operator,(const descr<N1, Ts1...> &a,
+                                                       const descr<N2, Ts2...> &b) {
+    return a + const_name(", ") + b;
+}
+
+template <size_t N, typename... Ts, typename... Args>
+constexpr auto concat(const descr<N, Ts...> &d, const Args &...args) {
+    return (d, ..., args);
+}
+#else
+template <size_t N, typename... Ts, typename... Args>
+constexpr auto concat(const descr<N, Ts...> &d, const Args &...args)
+    -> decltype(std::declval<descr<N + 2, Ts...>>() + concat(args...)) {
+    return d + const_name(", ") + concat(args...);
+}
+#endif
+
+template <size_t N, typename... Ts>
+constexpr descr<N + 2, Ts...> type_descr(const descr<N, Ts...> &descr) {
+    return const_name("{") + descr + const_name("}");
+}
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/detail/init.h

@@ -0,0 +1,434 @@
+/*
+    pybind11/detail/init.h: init factory function implementation and support code.
+
+    Copyright (c) 2017 Jason Rhinelander <jason@imaginary.ca>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "class.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+PYBIND11_WARNING_DISABLE_MSVC(4127)
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+template <>
+class type_caster<value_and_holder> {
+public:
+    bool load(handle h, bool) {
+        value = reinterpret_cast<value_and_holder *>(h.ptr());
+        return true;
+    }
+
+    template <typename>
+    using cast_op_type = value_and_holder &;
+    explicit operator value_and_holder &() { return *value; }
+    static constexpr auto name = const_name<value_and_holder>();
+
+private:
+    value_and_holder *value = nullptr;
+};
+
+PYBIND11_NAMESPACE_BEGIN(initimpl)
+
+inline void no_nullptr(void *ptr) {
+    if (!ptr) {
+        throw type_error("pybind11::init(): factory function returned nullptr");
+    }
+}
+
+// Implementing functions for all forms of py::init<...> and py::init(...)
+template <typename Class>
+using Cpp = typename Class::type;
+template <typename Class>
+using Alias = typename Class::type_alias;
+template <typename Class>
+using Holder = typename Class::holder_type;
+
+template <typename Class>
+using is_alias_constructible = std::is_constructible<Alias<Class>, Cpp<Class> &&>;
+
+// Takes a Cpp pointer and returns true if it actually is a polymorphic Alias instance.
+template <typename Class, enable_if_t<Class::has_alias, int> = 0>
+bool is_alias(Cpp<Class> *ptr) {
+    return dynamic_cast<Alias<Class> *>(ptr) != nullptr;
+}
+// Failing fallback version of the above for a no-alias class (always returns false)
+template <typename /*Class*/>
+constexpr bool is_alias(void *) {
+    return false;
+}
+
+// Constructs and returns a new object; if the given arguments don't map to a constructor, we fall
+// back to brace aggregate initiailization so that for aggregate initialization can be used with
+// py::init, e.g.  `py::init<int, int>` to initialize a `struct T { int a; int b; }`.  For
+// non-aggregate types, we need to use an ordinary T(...) constructor (invoking as `T{...}` usually
+// works, but will not do the expected thing when `T` has an `initializer_list<T>` constructor).
+template <typename Class,
+          typename... Args,
+          detail::enable_if_t<std::is_constructible<Class, Args...>::value, int> = 0>
+inline Class *construct_or_initialize(Args &&...args) {
+    return new Class(std::forward<Args>(args)...);
+}
+template <typename Class,
+          typename... Args,
+          detail::enable_if_t<!std::is_constructible<Class, Args...>::value, int> = 0>
+inline Class *construct_or_initialize(Args &&...args) {
+    return new Class{std::forward<Args>(args)...};
+}
+
+// Attempts to constructs an alias using a `Alias(Cpp &&)` constructor.  This allows types with
+// an alias to provide only a single Cpp factory function as long as the Alias can be
+// constructed from an rvalue reference of the base Cpp type.  This means that Alias classes
+// can, when appropriate, simply define a `Alias(Cpp &&)` constructor rather than needing to
+// inherit all the base class constructors.
+template <typename Class>
+void construct_alias_from_cpp(std::true_type /*is_alias_constructible*/,
+                              value_and_holder &v_h,
+                              Cpp<Class> &&base) {
+    v_h.value_ptr() = new Alias<Class>(std::move(base));
+}
+template <typename Class>
+[[noreturn]] void construct_alias_from_cpp(std::false_type /*!is_alias_constructible*/,
+                                           value_and_holder &,
+                                           Cpp<Class> &&) {
+    throw type_error("pybind11::init(): unable to convert returned instance to required "
+                     "alias class: no `Alias<Class>(Class &&)` constructor available");
+}
+
+// Error-generating fallback for factories that don't match one of the below construction
+// mechanisms.
+template <typename Class>
+void construct(...) {
+    static_assert(!std::is_same<Class, Class>::value /* always false */,
+                  "pybind11::init(): init function must return a compatible pointer, "
+                  "holder, or value");
+}
+
+// Pointer return v1: the factory function returns a class pointer for a registered class.
+// If we don't need an alias (because this class doesn't have one, or because the final type is
+// inherited on the Python side) we can simply take over ownership.  Otherwise we need to try to
+// construct an Alias from the returned base instance.
+template <typename Class>
+void construct(value_and_holder &v_h, Cpp<Class> *ptr, bool need_alias) {
+    PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(need_alias);
+    no_nullptr(ptr);
+    if (Class::has_alias && need_alias && !is_alias<Class>(ptr)) {
+        // We're going to try to construct an alias by moving the cpp type.  Whether or not
+        // that succeeds, we still need to destroy the original cpp pointer (either the
+        // moved away leftover, if the alias construction works, or the value itself if we
+        // throw an error), but we can't just call `delete ptr`: it might have a special
+        // deleter, or might be shared_from_this.  So we construct a holder around it as if
+        // it was a normal instance, then steal the holder away into a local variable; thus
+        // the holder and destruction happens when we leave the C++ scope, and the holder
+        // class gets to handle the destruction however it likes.
+        v_h.value_ptr() = ptr;
+        v_h.set_instance_registered(true);          // To prevent init_instance from registering it
+        v_h.type->init_instance(v_h.inst, nullptr); // Set up the holder
+        Holder<Class> temp_holder(std::move(v_h.holder<Holder<Class>>())); // Steal the holder
+        v_h.type->dealloc(v_h); // Destroys the moved-out holder remains, resets value ptr to null
+        v_h.set_instance_registered(false);
+
+        construct_alias_from_cpp<Class>(is_alias_constructible<Class>{}, v_h, std::move(*ptr));
+    } else {
+        // Otherwise the type isn't inherited, so we don't need an Alias
+        v_h.value_ptr() = ptr;
+    }
+}
+
+// Pointer return v2: a factory that always returns an alias instance ptr.  We simply take over
+// ownership of the pointer.
+template <typename Class, enable_if_t<Class::has_alias, int> = 0>
+void construct(value_and_holder &v_h, Alias<Class> *alias_ptr, bool) {
+    no_nullptr(alias_ptr);
+    v_h.value_ptr() = static_cast<Cpp<Class> *>(alias_ptr);
+}
+
+// Holder return: copy its pointer, and move or copy the returned holder into the new instance's
+// holder.  This also handles types like std::shared_ptr<T> and std::unique_ptr<T> where T is a
+// derived type (through those holder's implicit conversion from derived class holder
+// constructors).
+template <typename Class>
+void construct(value_and_holder &v_h, Holder<Class> holder, bool need_alias) {
+    PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(need_alias);
+    auto *ptr = holder_helper<Holder<Class>>::get(holder);
+    no_nullptr(ptr);
+    // If we need an alias, check that the held pointer is actually an alias instance
+    if (Class::has_alias && need_alias && !is_alias<Class>(ptr)) {
+        throw type_error("pybind11::init(): construction failed: returned holder-wrapped instance "
+                         "is not an alias instance");
+    }
+
+    v_h.value_ptr() = ptr;
+    v_h.type->init_instance(v_h.inst, &holder);
+}
+
+// return-by-value version 1: returning a cpp class by value.  If the class has an alias and an
+// alias is required the alias must have an `Alias(Cpp &&)` constructor so that we can construct
+// the alias from the base when needed (i.e. because of Python-side inheritance).  When we don't
+// need it, we simply move-construct the cpp value into a new instance.
+template <typename Class>
+void construct(value_and_holder &v_h, Cpp<Class> &&result, bool need_alias) {
+    PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(need_alias);
+    static_assert(is_move_constructible<Cpp<Class>>::value,
+                  "pybind11::init() return-by-value factory function requires a movable class");
+    if (Class::has_alias && need_alias) {
+        construct_alias_from_cpp<Class>(is_alias_constructible<Class>{}, v_h, std::move(result));
+    } else {
+        v_h.value_ptr() = new Cpp<Class>(std::move(result));
+    }
+}
+
+// return-by-value version 2: returning a value of the alias type itself.  We move-construct an
+// Alias instance (even if no the python-side inheritance is involved).  The is intended for
+// cases where Alias initialization is always desired.
+template <typename Class>
+void construct(value_and_holder &v_h, Alias<Class> &&result, bool) {
+    static_assert(
+        is_move_constructible<Alias<Class>>::value,
+        "pybind11::init() return-by-alias-value factory function requires a movable alias class");
+    v_h.value_ptr() = new Alias<Class>(std::move(result));
+}
+
+// Implementing class for py::init<...>()
+template <typename... Args>
+struct constructor {
+    template <typename Class, typename... Extra, enable_if_t<!Class::has_alias, int> = 0>
+    static void execute(Class &cl, const Extra &...extra) {
+        cl.def(
+            "__init__",
+            [](value_and_holder &v_h, Args... args) {
+                v_h.value_ptr() = construct_or_initialize<Cpp<Class>>(std::forward<Args>(args)...);
+            },
+            is_new_style_constructor(),
+            extra...);
+    }
+
+    template <
+        typename Class,
+        typename... Extra,
+        enable_if_t<Class::has_alias && std::is_constructible<Cpp<Class>, Args...>::value, int>
+        = 0>
+    static void execute(Class &cl, const Extra &...extra) {
+        cl.def(
+            "__init__",
+            [](value_and_holder &v_h, Args... args) {
+                if (Py_TYPE(v_h.inst) == v_h.type->type) {
+                    v_h.value_ptr()
+                        = construct_or_initialize<Cpp<Class>>(std::forward<Args>(args)...);
+                } else {
+                    v_h.value_ptr()
+                        = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
+                }
+            },
+            is_new_style_constructor(),
+            extra...);
+    }
+
+    template <
+        typename Class,
+        typename... Extra,
+        enable_if_t<Class::has_alias && !std::is_constructible<Cpp<Class>, Args...>::value, int>
+        = 0>
+    static void execute(Class &cl, const Extra &...extra) {
+        cl.def(
+            "__init__",
+            [](value_and_holder &v_h, Args... args) {
+                v_h.value_ptr()
+                    = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
+            },
+            is_new_style_constructor(),
+            extra...);
+    }
+};
+
+// Implementing class for py::init_alias<...>()
+template <typename... Args>
+struct alias_constructor {
+    template <
+        typename Class,
+        typename... Extra,
+        enable_if_t<Class::has_alias && std::is_constructible<Alias<Class>, Args...>::value, int>
+        = 0>
+    static void execute(Class &cl, const Extra &...extra) {
+        cl.def(
+            "__init__",
+            [](value_and_holder &v_h, Args... args) {
+                v_h.value_ptr()
+                    = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
+            },
+            is_new_style_constructor(),
+            extra...);
+    }
+};
+
+// Implementation class for py::init(Func) and py::init(Func, AliasFunc)
+template <typename CFunc,
+          typename AFunc = void_type (*)(),
+          typename = function_signature_t<CFunc>,
+          typename = function_signature_t<AFunc>>
+struct factory;
+
+// Specialization for py::init(Func)
+template <typename Func, typename Return, typename... Args>
+struct factory<Func, void_type (*)(), Return(Args...)> {
+    remove_reference_t<Func> class_factory;
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    factory(Func &&f) : class_factory(std::forward<Func>(f)) {}
+
+    // The given class either has no alias or has no separate alias factory;
+    // this always constructs the class itself.  If the class is registered with an alias
+    // type and an alias instance is needed (i.e. because the final type is a Python class
+    // inheriting from the C++ type) the returned value needs to either already be an alias
+    // instance, or the alias needs to be constructible from a `Class &&` argument.
+    template <typename Class, typename... Extra>
+    void execute(Class &cl, const Extra &...extra) && {
+#if defined(PYBIND11_CPP14)
+        cl.def(
+            "__init__",
+            [func = std::move(class_factory)]
+#else
+        auto &func = class_factory;
+        cl.def(
+            "__init__",
+            [func]
+#endif
+            (value_and_holder &v_h, Args... args) {
+                construct<Class>(
+                    v_h, func(std::forward<Args>(args)...), Py_TYPE(v_h.inst) != v_h.type->type);
+            },
+            is_new_style_constructor(),
+            extra...);
+    }
+};
+
+// Specialization for py::init(Func, AliasFunc)
+template <typename CFunc,
+          typename AFunc,
+          typename CReturn,
+          typename... CArgs,
+          typename AReturn,
+          typename... AArgs>
+struct factory<CFunc, AFunc, CReturn(CArgs...), AReturn(AArgs...)> {
+    static_assert(sizeof...(CArgs) == sizeof...(AArgs),
+                  "pybind11::init(class_factory, alias_factory): class and alias factories "
+                  "must have identical argument signatures");
+    static_assert(all_of<std::is_same<CArgs, AArgs>...>::value,
+                  "pybind11::init(class_factory, alias_factory): class and alias factories "
+                  "must have identical argument signatures");
+
+    remove_reference_t<CFunc> class_factory;
+    remove_reference_t<AFunc> alias_factory;
+
+    factory(CFunc &&c, AFunc &&a)
+        : class_factory(std::forward<CFunc>(c)), alias_factory(std::forward<AFunc>(a)) {}
+
+    // The class factory is called when the `self` type passed to `__init__` is the direct
+    // class (i.e. not inherited), the alias factory when `self` is a Python-side subtype.
+    template <typename Class, typename... Extra>
+    void execute(Class &cl, const Extra &...extra) && {
+        static_assert(Class::has_alias,
+                      "The two-argument version of `py::init()` can "
+                      "only be used if the class has an alias");
+#if defined(PYBIND11_CPP14)
+        cl.def(
+            "__init__",
+            [class_func = std::move(class_factory), alias_func = std::move(alias_factory)]
+#else
+        auto &class_func = class_factory;
+        auto &alias_func = alias_factory;
+        cl.def(
+            "__init__",
+            [class_func, alias_func]
+#endif
+            (value_and_holder &v_h, CArgs... args) {
+                if (Py_TYPE(v_h.inst) == v_h.type->type) {
+                    // If the instance type equals the registered type we don't have inheritance,
+                    // so don't need the alias and can construct using the class function:
+                    construct<Class>(v_h, class_func(std::forward<CArgs>(args)...), false);
+                } else {
+                    construct<Class>(v_h, alias_func(std::forward<CArgs>(args)...), true);
+                }
+            },
+            is_new_style_constructor(),
+            extra...);
+    }
+};
+
+/// Set just the C++ state. Same as `__init__`.
+template <typename Class, typename T>
+void setstate(value_and_holder &v_h, T &&result, bool need_alias) {
+    construct<Class>(v_h, std::forward<T>(result), need_alias);
+}
+
+/// Set both the C++ and Python states
+template <typename Class,
+          typename T,
+          typename O,
+          enable_if_t<std::is_convertible<O, handle>::value, int> = 0>
+void setstate(value_and_holder &v_h, std::pair<T, O> &&result, bool need_alias) {
+    construct<Class>(v_h, std::move(result.first), need_alias);
+    auto d = handle(result.second);
+    if (PyDict_Check(d.ptr()) && PyDict_Size(d.ptr()) == 0) {
+        // Skipping setattr below, to not force use of py::dynamic_attr() for Class unnecessarily.
+        // See PR #2972 for details.
+        return;
+    }
+    setattr((PyObject *) v_h.inst, "__dict__", d);
+}
+
+/// Implementation for py::pickle(GetState, SetState)
+template <typename Get,
+          typename Set,
+          typename = function_signature_t<Get>,
+          typename = function_signature_t<Set>>
+struct pickle_factory;
+
+template <typename Get,
+          typename Set,
+          typename RetState,
+          typename Self,
+          typename NewInstance,
+          typename ArgState>
+struct pickle_factory<Get, Set, RetState(Self), NewInstance(ArgState)> {
+    static_assert(std::is_same<intrinsic_t<RetState>, intrinsic_t<ArgState>>::value,
+                  "The type returned by `__getstate__` must be the same "
+                  "as the argument accepted by `__setstate__`");
+
+    remove_reference_t<Get> get;
+    remove_reference_t<Set> set;
+
+    pickle_factory(Get get, Set set) : get(std::forward<Get>(get)), set(std::forward<Set>(set)) {}
+
+    template <typename Class, typename... Extra>
+    void execute(Class &cl, const Extra &...extra) && {
+        cl.def("__getstate__", std::move(get));
+
+#if defined(PYBIND11_CPP14)
+        cl.def(
+            "__setstate__",
+            [func = std::move(set)]
+#else
+        auto &func = set;
+        cl.def(
+            "__setstate__",
+            [func]
+#endif
+            (value_and_holder &v_h, ArgState state) {
+                setstate<Class>(
+                    v_h, func(std::forward<ArgState>(state)), Py_TYPE(v_h.inst) != v_h.type->type);
+            },
+            is_new_style_constructor(),
+            extra...);
+    }
+};
+
+PYBIND11_NAMESPACE_END(initimpl)
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/detail/internals.h

@@ -0,0 +1,656 @@
+/*
+    pybind11/detail/internals.h: Internal data structure and related functions
+
+    Copyright (c) 2017 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "common.h"
+
+#if defined(WITH_THREAD) && defined(PYBIND11_SIMPLE_GIL_MANAGEMENT)
+#    include "../gil.h"
+#endif
+
+#include "../pytypes.h"
+
+#include <exception>
+
+/// Tracks the `internals` and `type_info` ABI version independent of the main library version.
+///
+/// Some portions of the code use an ABI that is conditional depending on this
+/// version number.  That allows ABI-breaking changes to be "pre-implemented".
+/// Once the default version number is incremented, the conditional logic that
+/// no longer applies can be removed.  Additionally, users that need not
+/// maintain ABI compatibility can increase the version number in order to take
+/// advantage of any functionality/efficiency improvements that depend on the
+/// newer ABI.
+///
+/// WARNING: If you choose to manually increase the ABI version, note that
+/// pybind11 may not be tested as thoroughly with a non-default ABI version, and
+/// further ABI-incompatible changes may be made before the ABI is officially
+/// changed to the new version.
+#ifndef PYBIND11_INTERNALS_VERSION
+#    if PY_VERSION_HEX >= 0x030C0000
+// Version bump for Python 3.12+, before first 3.12 beta release.
+#        define PYBIND11_INTERNALS_VERSION 5
+#    else
+#        define PYBIND11_INTERNALS_VERSION 4
+#    endif
+#endif
+
+// This requirement is mainly to reduce the support burden (see PR #4570).
+static_assert(PY_VERSION_HEX < 0x030C0000 || PYBIND11_INTERNALS_VERSION >= 5,
+              "pybind11 ABI version 5 is the minimum for Python 3.12+");
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+using ExceptionTranslator = void (*)(std::exception_ptr);
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+constexpr const char *internals_function_record_capsule_name = "pybind11_function_record_capsule";
+
+// Forward declarations
+inline PyTypeObject *make_static_property_type();
+inline PyTypeObject *make_default_metaclass();
+inline PyObject *make_object_base_type(PyTypeObject *metaclass);
+
+// The old Python Thread Local Storage (TLS) API is deprecated in Python 3.7 in favor of the new
+// Thread Specific Storage (TSS) API.
+#if PY_VERSION_HEX >= 0x03070000
+// Avoid unnecessary allocation of `Py_tss_t`, since we cannot use
+// `Py_LIMITED_API` anyway.
+#    if PYBIND11_INTERNALS_VERSION > 4
+#        define PYBIND11_TLS_KEY_REF Py_tss_t &
+#        if defined(__GNUC__) && !defined(__INTEL_COMPILER)
+// Clang on macOS warns due to `Py_tss_NEEDS_INIT` not specifying an initializer
+// for every field.
+#            define PYBIND11_TLS_KEY_INIT(var)                                                    \
+                _Pragma("GCC diagnostic push")                                         /**/       \
+                    _Pragma("GCC diagnostic ignored \"-Wmissing-field-initializers\"") /**/       \
+                    Py_tss_t var                                                                  \
+                    = Py_tss_NEEDS_INIT;                                                          \
+                _Pragma("GCC diagnostic pop")
+#        else
+#            define PYBIND11_TLS_KEY_INIT(var) Py_tss_t var = Py_tss_NEEDS_INIT;
+#        endif
+#        define PYBIND11_TLS_KEY_CREATE(var) (PyThread_tss_create(&(var)) == 0)
+#        define PYBIND11_TLS_GET_VALUE(key) PyThread_tss_get(&(key))
+#        define PYBIND11_TLS_REPLACE_VALUE(key, value) PyThread_tss_set(&(key), (value))
+#        define PYBIND11_TLS_DELETE_VALUE(key) PyThread_tss_set(&(key), nullptr)
+#        define PYBIND11_TLS_FREE(key) PyThread_tss_delete(&(key))
+#    else
+#        define PYBIND11_TLS_KEY_REF Py_tss_t *
+#        define PYBIND11_TLS_KEY_INIT(var) Py_tss_t *var = nullptr;
+#        define PYBIND11_TLS_KEY_CREATE(var)                                                      \
+            (((var) = PyThread_tss_alloc()) != nullptr && (PyThread_tss_create((var)) == 0))
+#        define PYBIND11_TLS_GET_VALUE(key) PyThread_tss_get((key))
+#        define PYBIND11_TLS_REPLACE_VALUE(key, value) PyThread_tss_set((key), (value))
+#        define PYBIND11_TLS_DELETE_VALUE(key) PyThread_tss_set((key), nullptr)
+#        define PYBIND11_TLS_FREE(key) PyThread_tss_free(key)
+#    endif
+#else
+// Usually an int but a long on Cygwin64 with Python 3.x
+#    define PYBIND11_TLS_KEY_REF decltype(PyThread_create_key())
+#    define PYBIND11_TLS_KEY_INIT(var) PYBIND11_TLS_KEY_REF var = 0;
+#    define PYBIND11_TLS_KEY_CREATE(var) (((var) = PyThread_create_key()) != -1)
+#    define PYBIND11_TLS_GET_VALUE(key) PyThread_get_key_value((key))
+#    if defined(PYPY_VERSION)
+// On CPython < 3.4 and on PyPy, `PyThread_set_key_value` strangely does not set
+// the value if it has already been set.  Instead, it must first be deleted and
+// then set again.
+inline void tls_replace_value(PYBIND11_TLS_KEY_REF key, void *value) {
+    PyThread_delete_key_value(key);
+    PyThread_set_key_value(key, value);
+}
+#        define PYBIND11_TLS_DELETE_VALUE(key) PyThread_delete_key_value(key)
+#        define PYBIND11_TLS_REPLACE_VALUE(key, value)                                            \
+            ::pybind11::detail::tls_replace_value((key), (value))
+#    else
+#        define PYBIND11_TLS_DELETE_VALUE(key) PyThread_set_key_value((key), nullptr)
+#        define PYBIND11_TLS_REPLACE_VALUE(key, value) PyThread_set_key_value((key), (value))
+#    endif
+#    define PYBIND11_TLS_FREE(key) (void) key
+#endif
+
+// Python loads modules by default with dlopen with the RTLD_LOCAL flag; under libc++ and possibly
+// other STLs, this means `typeid(A)` from one module won't equal `typeid(A)` from another module
+// even when `A` is the same, non-hidden-visibility type (e.g. from a common include).  Under
+// libstdc++, this doesn't happen: equality and the type_index hash are based on the type name,
+// which works.  If not under a known-good stl, provide our own name-based hash and equality
+// functions that use the type name.
+#if (PYBIND11_INTERNALS_VERSION <= 4 && defined(__GLIBCXX__))                                     \
+    || (PYBIND11_INTERNALS_VERSION >= 5 && !defined(_LIBCPP_VERSION))
+inline bool same_type(const std::type_info &lhs, const std::type_info &rhs) { return lhs == rhs; }
+using type_hash = std::hash<std::type_index>;
+using type_equal_to = std::equal_to<std::type_index>;
+#else
+inline bool same_type(const std::type_info &lhs, const std::type_info &rhs) {
+    return lhs.name() == rhs.name() || std::strcmp(lhs.name(), rhs.name()) == 0;
+}
+
+struct type_hash {
+    size_t operator()(const std::type_index &t) const {
+        size_t hash = 5381;
+        const char *ptr = t.name();
+        while (auto c = static_cast<unsigned char>(*ptr++)) {
+            hash = (hash * 33) ^ c;
+        }
+        return hash;
+    }
+};
+
+struct type_equal_to {
+    bool operator()(const std::type_index &lhs, const std::type_index &rhs) const {
+        return lhs.name() == rhs.name() || std::strcmp(lhs.name(), rhs.name()) == 0;
+    }
+};
+#endif
+
+template <typename value_type>
+using type_map = std::unordered_map<std::type_index, value_type, type_hash, type_equal_to>;
+
+struct override_hash {
+    inline size_t operator()(const std::pair<const PyObject *, const char *> &v) const {
+        size_t value = std::hash<const void *>()(v.first);
+        value ^= std::hash<const void *>()(v.second) + 0x9e3779b9 + (value << 6) + (value >> 2);
+        return value;
+    }
+};
+
+/// Internal data structure used to track registered instances and types.
+/// Whenever binary incompatible changes are made to this structure,
+/// `PYBIND11_INTERNALS_VERSION` must be incremented.
+struct internals {
+    // std::type_index -> pybind11's type information
+    type_map<type_info *> registered_types_cpp;
+    // PyTypeObject* -> base type_info(s)
+    std::unordered_map<PyTypeObject *, std::vector<type_info *>> registered_types_py;
+    std::unordered_multimap<const void *, instance *> registered_instances; // void * -> instance*
+    std::unordered_set<std::pair<const PyObject *, const char *>, override_hash>
+        inactive_override_cache;
+    type_map<std::vector<bool (*)(PyObject *, void *&)>> direct_conversions;
+    std::unordered_map<const PyObject *, std::vector<PyObject *>> patients;
+    std::forward_list<ExceptionTranslator> registered_exception_translators;
+    std::unordered_map<std::string, void *> shared_data; // Custom data to be shared across
+                                                         // extensions
+#if PYBIND11_INTERNALS_VERSION == 4
+    std::vector<PyObject *> unused_loader_patient_stack_remove_at_v5;
+#endif
+    std::forward_list<std::string> static_strings; // Stores the std::strings backing
+                                                   // detail::c_str()
+    PyTypeObject *static_property_type;
+    PyTypeObject *default_metaclass;
+    PyObject *instance_base;
+#if defined(WITH_THREAD)
+    // Unused if PYBIND11_SIMPLE_GIL_MANAGEMENT is defined:
+    PYBIND11_TLS_KEY_INIT(tstate)
+#    if PYBIND11_INTERNALS_VERSION > 4
+    PYBIND11_TLS_KEY_INIT(loader_life_support_tls_key)
+#    endif // PYBIND11_INTERNALS_VERSION > 4
+    // Unused if PYBIND11_SIMPLE_GIL_MANAGEMENT is defined:
+    PyInterpreterState *istate = nullptr;
+
+#    if PYBIND11_INTERNALS_VERSION > 4
+    // Note that we have to use a std::string to allocate memory to ensure a unique address
+    // We want unique addresses since we use pointer equality to compare function records
+    std::string function_record_capsule_name = internals_function_record_capsule_name;
+#    endif
+
+    internals() = default;
+    internals(const internals &other) = delete;
+    internals &operator=(const internals &other) = delete;
+    ~internals() {
+#    if PYBIND11_INTERNALS_VERSION > 4
+        PYBIND11_TLS_FREE(loader_life_support_tls_key);
+#    endif // PYBIND11_INTERNALS_VERSION > 4
+
+        // This destructor is called *after* Py_Finalize() in finalize_interpreter().
+        // That *SHOULD BE* fine. The following details what happens when PyThread_tss_free is
+        // called. PYBIND11_TLS_FREE is PyThread_tss_free on python 3.7+. On older python, it does
+        // nothing. PyThread_tss_free calls PyThread_tss_delete and PyMem_RawFree.
+        // PyThread_tss_delete just calls TlsFree (on Windows) or pthread_key_delete (on *NIX).
+        // Neither of those have anything to do with CPython internals. PyMem_RawFree *requires*
+        // that the `tstate` be allocated with the CPython allocator.
+        PYBIND11_TLS_FREE(tstate);
+    }
+#endif
+};
+
+/// Additional type information which does not fit into the PyTypeObject.
+/// Changes to this struct also require bumping `PYBIND11_INTERNALS_VERSION`.
+struct type_info {
+    PyTypeObject *type;
+    const std::type_info *cpptype;
+    size_t type_size, type_align, holder_size_in_ptrs;
+    void *(*operator_new)(size_t);
+    void (*init_instance)(instance *, const void *);
+    void (*dealloc)(value_and_holder &v_h);
+    std::vector<PyObject *(*) (PyObject *, PyTypeObject *)> implicit_conversions;
+    std::vector<std::pair<const std::type_info *, void *(*) (void *)>> implicit_casts;
+    std::vector<bool (*)(PyObject *, void *&)> *direct_conversions;
+    buffer_info *(*get_buffer)(PyObject *, void *) = nullptr;
+    void *get_buffer_data = nullptr;
+    void *(*module_local_load)(PyObject *, const type_info *) = nullptr;
+    /* A simple type never occurs as a (direct or indirect) parent
+     * of a class that makes use of multiple inheritance.
+     * A type can be simple even if it has non-simple ancestors as long as it has no descendants.
+     */
+    bool simple_type : 1;
+    /* True if there is no multiple inheritance in this type's inheritance tree */
+    bool simple_ancestors : 1;
+    /* for base vs derived holder_type checks */
+    bool default_holder : 1;
+    /* true if this is a type registered with py::module_local */
+    bool module_local : 1;
+};
+
+/// On MSVC, debug and release builds are not ABI-compatible!
+#if defined(_MSC_VER) && defined(_DEBUG)
+#    define PYBIND11_BUILD_TYPE "_debug"
+#else
+#    define PYBIND11_BUILD_TYPE ""
+#endif
+
+/// Let's assume that different compilers are ABI-incompatible.
+/// A user can manually set this string if they know their
+/// compiler is compatible.
+#ifndef PYBIND11_COMPILER_TYPE
+#    if defined(_MSC_VER)
+#        define PYBIND11_COMPILER_TYPE "_msvc"
+#    elif defined(__INTEL_COMPILER)
+#        define PYBIND11_COMPILER_TYPE "_icc"
+#    elif defined(__clang__)
+#        define PYBIND11_COMPILER_TYPE "_clang"
+#    elif defined(__PGI)
+#        define PYBIND11_COMPILER_TYPE "_pgi"
+#    elif defined(__MINGW32__)
+#        define PYBIND11_COMPILER_TYPE "_mingw"
+#    elif defined(__CYGWIN__)
+#        define PYBIND11_COMPILER_TYPE "_gcc_cygwin"
+#    elif defined(__GNUC__)
+#        define PYBIND11_COMPILER_TYPE "_gcc"
+#    else
+#        define PYBIND11_COMPILER_TYPE "_unknown"
+#    endif
+#endif
+
+/// Also standard libs
+#ifndef PYBIND11_STDLIB
+#    if defined(_LIBCPP_VERSION)
+#        define PYBIND11_STDLIB "_libcpp"
+#    elif defined(__GLIBCXX__) || defined(__GLIBCPP__)
+#        define PYBIND11_STDLIB "_libstdcpp"
+#    else
+#        define PYBIND11_STDLIB ""
+#    endif
+#endif
+
+/// On Linux/OSX, changes in __GXX_ABI_VERSION__ indicate ABI incompatibility.
+#ifndef PYBIND11_BUILD_ABI
+#    if defined(__GXX_ABI_VERSION)
+#        define PYBIND11_BUILD_ABI "_cxxabi" PYBIND11_TOSTRING(__GXX_ABI_VERSION)
+#    else
+#        define PYBIND11_BUILD_ABI ""
+#    endif
+#endif
+
+#ifndef PYBIND11_INTERNALS_KIND
+#    if defined(WITH_THREAD)
+#        define PYBIND11_INTERNALS_KIND ""
+#    else
+#        define PYBIND11_INTERNALS_KIND "_without_thread"
+#    endif
+#endif
+
+#define PYBIND11_INTERNALS_ID                                                                     \
+    "__pybind11_internals_v" PYBIND11_TOSTRING(PYBIND11_INTERNALS_VERSION)                        \
+        PYBIND11_INTERNALS_KIND PYBIND11_COMPILER_TYPE PYBIND11_STDLIB PYBIND11_BUILD_ABI         \
+            PYBIND11_BUILD_TYPE "__"
+
+#define PYBIND11_MODULE_LOCAL_ID                                                                  \
+    "__pybind11_module_local_v" PYBIND11_TOSTRING(PYBIND11_INTERNALS_VERSION)                     \
+        PYBIND11_INTERNALS_KIND PYBIND11_COMPILER_TYPE PYBIND11_STDLIB PYBIND11_BUILD_ABI         \
+            PYBIND11_BUILD_TYPE "__"
+
+/// Each module locally stores a pointer to the `internals` data. The data
+/// itself is shared among modules with the same `PYBIND11_INTERNALS_ID`.
+inline internals **&get_internals_pp() {
+    static internals **internals_pp = nullptr;
+    return internals_pp;
+}
+
+// forward decl
+inline void translate_exception(std::exception_ptr);
+
+template <class T,
+          enable_if_t<std::is_same<std::nested_exception, remove_cvref_t<T>>::value, int> = 0>
+bool handle_nested_exception(const T &exc, const std::exception_ptr &p) {
+    std::exception_ptr nested = exc.nested_ptr();
+    if (nested != nullptr && nested != p) {
+        translate_exception(nested);
+        return true;
+    }
+    return false;
+}
+
+template <class T,
+          enable_if_t<!std::is_same<std::nested_exception, remove_cvref_t<T>>::value, int> = 0>
+bool handle_nested_exception(const T &exc, const std::exception_ptr &p) {
+    if (const auto *nep = dynamic_cast<const std::nested_exception *>(std::addressof(exc))) {
+        return handle_nested_exception(*nep, p);
+    }
+    return false;
+}
+
+inline bool raise_err(PyObject *exc_type, const char *msg) {
+    if (PyErr_Occurred()) {
+        raise_from(exc_type, msg);
+        return true;
+    }
+    PyErr_SetString(exc_type, msg);
+    return false;
+}
+
+inline void translate_exception(std::exception_ptr p) {
+    if (!p) {
+        return;
+    }
+    try {
+        std::rethrow_exception(p);
+    } catch (error_already_set &e) {
+        handle_nested_exception(e, p);
+        e.restore();
+        return;
+    } catch (const builtin_exception &e) {
+        // Could not use template since it's an abstract class.
+        if (const auto *nep = dynamic_cast<const std::nested_exception *>(std::addressof(e))) {
+            handle_nested_exception(*nep, p);
+        }
+        e.set_error();
+        return;
+    } catch (const std::bad_alloc &e) {
+        handle_nested_exception(e, p);
+        raise_err(PyExc_MemoryError, e.what());
+        return;
+    } catch (const std::domain_error &e) {
+        handle_nested_exception(e, p);
+        raise_err(PyExc_ValueError, e.what());
+        return;
+    } catch (const std::invalid_argument &e) {
+        handle_nested_exception(e, p);
+        raise_err(PyExc_ValueError, e.what());
+        return;
+    } catch (const std::length_error &e) {
+        handle_nested_exception(e, p);
+        raise_err(PyExc_ValueError, e.what());
+        return;
+    } catch (const std::out_of_range &e) {
+        handle_nested_exception(e, p);
+        raise_err(PyExc_IndexError, e.what());
+        return;
+    } catch (const std::range_error &e) {
+        handle_nested_exception(e, p);
+        raise_err(PyExc_ValueError, e.what());
+        return;
+    } catch (const std::overflow_error &e) {
+        handle_nested_exception(e, p);
+        raise_err(PyExc_OverflowError, e.what());
+        return;
+    } catch (const std::exception &e) {
+        handle_nested_exception(e, p);
+        raise_err(PyExc_RuntimeError, e.what());
+        return;
+    } catch (const std::nested_exception &e) {
+        handle_nested_exception(e, p);
+        raise_err(PyExc_RuntimeError, "Caught an unknown nested exception!");
+        return;
+    } catch (...) {
+        raise_err(PyExc_RuntimeError, "Caught an unknown exception!");
+        return;
+    }
+}
+
+#if !defined(__GLIBCXX__)
+inline void translate_local_exception(std::exception_ptr p) {
+    try {
+        if (p) {
+            std::rethrow_exception(p);
+        }
+    } catch (error_already_set &e) {
+        e.restore();
+        return;
+    } catch (const builtin_exception &e) {
+        e.set_error();
+        return;
+    }
+}
+#endif
+
+inline object get_python_state_dict() {
+    object state_dict;
+#if PYBIND11_INTERNALS_VERSION <= 4 || PY_VERSION_HEX < 0x03080000 || defined(PYPY_VERSION)
+    state_dict = reinterpret_borrow<object>(PyEval_GetBuiltins());
+#else
+#    if PY_VERSION_HEX < 0x03090000
+    PyInterpreterState *istate = _PyInterpreterState_Get();
+#    else
+    PyInterpreterState *istate = PyInterpreterState_Get();
+#    endif
+    if (istate) {
+        state_dict = reinterpret_borrow<object>(PyInterpreterState_GetDict(istate));
+    }
+#endif
+    if (!state_dict) {
+        raise_from(PyExc_SystemError, "pybind11::detail::get_python_state_dict() FAILED");
+    }
+    return state_dict;
+}
+
+inline object get_internals_obj_from_state_dict(handle state_dict) {
+    return reinterpret_borrow<object>(dict_getitemstring(state_dict.ptr(), PYBIND11_INTERNALS_ID));
+}
+
+inline internals **get_internals_pp_from_capsule(handle obj) {
+    void *raw_ptr = PyCapsule_GetPointer(obj.ptr(), /*name=*/nullptr);
+    if (raw_ptr == nullptr) {
+        raise_from(PyExc_SystemError, "pybind11::detail::get_internals_pp_from_capsule() FAILED");
+    }
+    return static_cast<internals **>(raw_ptr);
+}
+
+/// Return a reference to the current `internals` data
+PYBIND11_NOINLINE internals &get_internals() {
+    auto **&internals_pp = get_internals_pp();
+    if (internals_pp && *internals_pp) {
+        return **internals_pp;
+    }
+
+#if defined(WITH_THREAD)
+#    if defined(PYBIND11_SIMPLE_GIL_MANAGEMENT)
+    gil_scoped_acquire gil;
+#    else
+    // Ensure that the GIL is held since we will need to make Python calls.
+    // Cannot use py::gil_scoped_acquire here since that constructor calls get_internals.
+    struct gil_scoped_acquire_local {
+        gil_scoped_acquire_local() : state(PyGILState_Ensure()) {}
+        gil_scoped_acquire_local(const gil_scoped_acquire_local &) = delete;
+        gil_scoped_acquire_local &operator=(const gil_scoped_acquire_local &) = delete;
+        ~gil_scoped_acquire_local() { PyGILState_Release(state); }
+        const PyGILState_STATE state;
+    } gil;
+#    endif
+#endif
+    error_scope err_scope;
+
+    dict state_dict = get_python_state_dict();
+    if (object internals_obj = get_internals_obj_from_state_dict(state_dict)) {
+        internals_pp = get_internals_pp_from_capsule(internals_obj);
+    }
+    if (internals_pp && *internals_pp) {
+        // We loaded the internals through `state_dict`, which means that our `error_already_set`
+        // and `builtin_exception` may be different local classes than the ones set up in the
+        // initial exception translator, below, so add another for our local exception classes.
+        //
+        // libstdc++ doesn't require this (types there are identified only by name)
+        // libc++ with CPython doesn't require this (types are explicitly exported)
+        // libc++ with PyPy still need it, awaiting further investigation
+#if !defined(__GLIBCXX__)
+        (*internals_pp)->registered_exception_translators.push_front(&translate_local_exception);
+#endif
+    } else {
+        if (!internals_pp) {
+            internals_pp = new internals *();
+        }
+        auto *&internals_ptr = *internals_pp;
+        internals_ptr = new internals();
+#if defined(WITH_THREAD)
+
+        PyThreadState *tstate = PyThreadState_Get();
+        // NOLINTNEXTLINE(bugprone-assignment-in-if-condition)
+        if (!PYBIND11_TLS_KEY_CREATE(internals_ptr->tstate)) {
+            pybind11_fail("get_internals: could not successfully initialize the tstate TSS key!");
+        }
+        PYBIND11_TLS_REPLACE_VALUE(internals_ptr->tstate, tstate);
+
+#    if PYBIND11_INTERNALS_VERSION > 4
+        // NOLINTNEXTLINE(bugprone-assignment-in-if-condition)
+        if (!PYBIND11_TLS_KEY_CREATE(internals_ptr->loader_life_support_tls_key)) {
+            pybind11_fail("get_internals: could not successfully initialize the "
+                          "loader_life_support TSS key!");
+        }
+#    endif
+        internals_ptr->istate = tstate->interp;
+#endif
+        state_dict[PYBIND11_INTERNALS_ID] = capsule(internals_pp);
+        internals_ptr->registered_exception_translators.push_front(&translate_exception);
+        internals_ptr->static_property_type = make_static_property_type();
+        internals_ptr->default_metaclass = make_default_metaclass();
+        internals_ptr->instance_base = make_object_base_type(internals_ptr->default_metaclass);
+    }
+    return **internals_pp;
+}
+
+// the internals struct (above) is shared between all the modules. local_internals are only
+// for a single module. Any changes made to internals may require an update to
+// PYBIND11_INTERNALS_VERSION, breaking backwards compatibility. local_internals is, by design,
+// restricted to a single module. Whether a module has local internals or not should not
+// impact any other modules, because the only things accessing the local internals is the
+// module that contains them.
+struct local_internals {
+    type_map<type_info *> registered_types_cpp;
+    std::forward_list<ExceptionTranslator> registered_exception_translators;
+#if defined(WITH_THREAD) && PYBIND11_INTERNALS_VERSION == 4
+
+    // For ABI compatibility, we can't store the loader_life_support TLS key in
+    // the `internals` struct directly.  Instead, we store it in `shared_data` and
+    // cache a copy in `local_internals`.  If we allocated a separate TLS key for
+    // each instance of `local_internals`, we could end up allocating hundreds of
+    // TLS keys if hundreds of different pybind11 modules are loaded (which is a
+    // plausible number).
+    PYBIND11_TLS_KEY_INIT(loader_life_support_tls_key)
+
+    // Holds the shared TLS key for the loader_life_support stack.
+    struct shared_loader_life_support_data {
+        PYBIND11_TLS_KEY_INIT(loader_life_support_tls_key)
+        shared_loader_life_support_data() {
+            // NOLINTNEXTLINE(bugprone-assignment-in-if-condition)
+            if (!PYBIND11_TLS_KEY_CREATE(loader_life_support_tls_key)) {
+                pybind11_fail("local_internals: could not successfully initialize the "
+                              "loader_life_support TLS key!");
+            }
+        }
+        // We can't help but leak the TLS key, because Python never unloads extension modules.
+    };
+
+    local_internals() {
+        auto &internals = get_internals();
+        // Get or create the `loader_life_support_stack_key`.
+        auto &ptr = internals.shared_data["_life_support"];
+        if (!ptr) {
+            ptr = new shared_loader_life_support_data;
+        }
+        loader_life_support_tls_key
+            = static_cast<shared_loader_life_support_data *>(ptr)->loader_life_support_tls_key;
+    }
+#endif //  defined(WITH_THREAD) && PYBIND11_INTERNALS_VERSION == 4
+};
+
+/// Works like `get_internals`, but for things which are locally registered.
+inline local_internals &get_local_internals() {
+    // Current static can be created in the interpreter finalization routine. If the later will be
+    // destroyed in another static variable destructor, creation of this static there will cause
+    // static deinitialization fiasco. In order to avoid it we avoid destruction of the
+    // local_internals static. One can read more about the problem and current solution here:
+    // https://google.github.io/styleguide/cppguide.html#Static_and_Global_Variables
+    static auto *locals = new local_internals();
+    return *locals;
+}
+
+/// Constructs a std::string with the given arguments, stores it in `internals`, and returns its
+/// `c_str()`.  Such strings objects have a long storage duration -- the internal strings are only
+/// cleared when the program exits or after interpreter shutdown (when embedding), and so are
+/// suitable for c-style strings needed by Python internals (such as PyTypeObject's tp_name).
+template <typename... Args>
+const char *c_str(Args &&...args) {
+    auto &strings = get_internals().static_strings;
+    strings.emplace_front(std::forward<Args>(args)...);
+    return strings.front().c_str();
+}
+
+inline const char *get_function_record_capsule_name() {
+#if PYBIND11_INTERNALS_VERSION > 4
+    return get_internals().function_record_capsule_name.c_str();
+#else
+    return nullptr;
+#endif
+}
+
+// Determine whether or not the following capsule contains a pybind11 function record.
+// Note that we use `internals` to make sure that only ABI compatible records are touched.
+//
+// This check is currently used in two places:
+// - An important optimization in functional.h to avoid overhead in C++ -> Python -> C++
+// - The sibling feature of cpp_function to allow overloads
+inline bool is_function_record_capsule(const capsule &cap) {
+    // Pointer equality as we rely on internals() to ensure unique pointers
+    return cap.name() == get_function_record_capsule_name();
+}
+
+PYBIND11_NAMESPACE_END(detail)
+
+/// Returns a named pointer that is shared among all extension modules (using the same
+/// pybind11 version) running in the current interpreter. Names starting with underscores
+/// are reserved for internal usage. Returns `nullptr` if no matching entry was found.
+PYBIND11_NOINLINE void *get_shared_data(const std::string &name) {
+    auto &internals = detail::get_internals();
+    auto it = internals.shared_data.find(name);
+    return it != internals.shared_data.end() ? it->second : nullptr;
+}
+
+/// Set the shared data that can be later recovered by `get_shared_data()`.
+PYBIND11_NOINLINE void *set_shared_data(const std::string &name, void *data) {
+    detail::get_internals().shared_data[name] = data;
+    return data;
+}
+
+/// Returns a typed reference to a shared data entry (by using `get_shared_data()`) if
+/// such entry exists. Otherwise, a new object of default-constructible type `T` is
+/// added to the shared data under the given name and a reference to it is returned.
+template <typename T>
+T &get_or_create_shared_data(const std::string &name) {
+    auto &internals = detail::get_internals();
+    auto it = internals.shared_data.find(name);
+    T *ptr = (T *) (it != internals.shared_data.end() ? it->second : nullptr);
+    if (!ptr) {
+        ptr = new T();
+        internals.shared_data[name] = ptr;
+    }
+    return *ptr;
+}
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/detail/typeid.h

@@ -0,0 +1,65 @@
+/*
+    pybind11/detail/typeid.h: Compiler-independent access to type identifiers
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include <cstdio>
+#include <cstdlib>
+
+#if defined(__GNUG__)
+#    include <cxxabi.h>
+#endif
+
+#include "common.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/// Erase all occurrences of a substring
+inline void erase_all(std::string &string, const std::string &search) {
+    for (size_t pos = 0;;) {
+        pos = string.find(search, pos);
+        if (pos == std::string::npos) {
+            break;
+        }
+        string.erase(pos, search.length());
+    }
+}
+
+PYBIND11_NOINLINE void clean_type_id(std::string &name) {
+#if defined(__GNUG__)
+    int status = 0;
+    std::unique_ptr<char, void (*)(void *)> res{
+        abi::__cxa_demangle(name.c_str(), nullptr, nullptr, &status), std::free};
+    if (status == 0) {
+        name = res.get();
+    }
+#else
+    detail::erase_all(name, "class ");
+    detail::erase_all(name, "struct ");
+    detail::erase_all(name, "enum ");
+#endif
+    detail::erase_all(name, "pybind11::");
+}
+
+inline std::string clean_type_id(const char *typeid_name) {
+    std::string name(typeid_name);
+    detail::clean_type_id(name);
+    return name;
+}
+
+PYBIND11_NAMESPACE_END(detail)
+
+/// Return a string representation of a C++ type
+template <typename T>
+static std::string type_id() {
+    return detail::clean_type_id(typeid(T).name());
+}
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/eigen.h

@@ -0,0 +1,12 @@
+/*
+    pybind11/eigen.h: Transparent conversion for dense and sparse Eigen matrices
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "eigen/matrix.h"

3rdparty/pybind11/include/pybind11/eigen/common.h

@@ -0,0 +1,9 @@
+// Copyright (c) 2023 The pybind Community.
+
+#pragma once
+
+// Common message for `static_assert()`s, which are useful to easily
+// preempt much less obvious errors.
+#define PYBIND11_EIGEN_MESSAGE_POINTER_TYPES_ARE_NOT_SUPPORTED                                    \
+    "Pointer types (in particular `PyObject *`) are not supported as scalar types for Eigen "     \
+    "types."

3rdparty/pybind11/include/pybind11/eigen/matrix.h

@@ -0,0 +1,714 @@
+/*
+    pybind11/eigen/matrix.h: Transparent conversion for dense and sparse Eigen matrices
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "../numpy.h"
+#include "common.h"
+
+/* HINT: To suppress warnings originating from the Eigen headers, use -isystem.
+   See also:
+       https://stackoverflow.com/questions/2579576/i-dir-vs-isystem-dir
+       https://stackoverflow.com/questions/1741816/isystem-for-ms-visual-studio-c-compiler
+*/
+PYBIND11_WARNING_PUSH
+PYBIND11_WARNING_DISABLE_MSVC(5054) // https://github.com/pybind/pybind11/pull/3741
+//       C5054: operator '&': deprecated between enumerations of different types
+#if defined(__MINGW32__)
+PYBIND11_WARNING_DISABLE_GCC("-Wmaybe-uninitialized")
+#endif
+
+#include <Eigen/Core>
+#include <Eigen/SparseCore>
+
+PYBIND11_WARNING_POP
+
+// Eigen prior to 3.2.7 doesn't have proper move constructors--but worse, some classes get implicit
+// move constructors that break things.  We could detect this an explicitly copy, but an extra copy
+// of matrices seems highly undesirable.
+static_assert(EIGEN_VERSION_AT_LEAST(3, 2, 7),
+              "Eigen matrix support in pybind11 requires Eigen >= 3.2.7");
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+PYBIND11_WARNING_DISABLE_MSVC(4127)
+
+// Provide a convenience alias for easier pass-by-ref usage with fully dynamic strides:
+using EigenDStride = Eigen::Stride<Eigen::Dynamic, Eigen::Dynamic>;
+template <typename MatrixType>
+using EigenDRef = Eigen::Ref<MatrixType, 0, EigenDStride>;
+template <typename MatrixType>
+using EigenDMap = Eigen::Map<MatrixType, 0, EigenDStride>;
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+#if EIGEN_VERSION_AT_LEAST(3, 3, 0)
+using EigenIndex = Eigen::Index;
+template <typename Scalar, int Flags, typename StorageIndex>
+using EigenMapSparseMatrix = Eigen::Map<Eigen::SparseMatrix<Scalar, Flags, StorageIndex>>;
+#else
+using EigenIndex = EIGEN_DEFAULT_DENSE_INDEX_TYPE;
+template <typename Scalar, int Flags, typename StorageIndex>
+using EigenMapSparseMatrix = Eigen::MappedSparseMatrix<Scalar, Flags, StorageIndex>;
+#endif
+
+// Matches Eigen::Map, Eigen::Ref, blocks, etc:
+template <typename T>
+using is_eigen_dense_map = all_of<is_template_base_of<Eigen::DenseBase, T>,
+                                  std::is_base_of<Eigen::MapBase<T, Eigen::ReadOnlyAccessors>, T>>;
+template <typename T>
+using is_eigen_mutable_map = std::is_base_of<Eigen::MapBase<T, Eigen::WriteAccessors>, T>;
+template <typename T>
+using is_eigen_dense_plain
+    = all_of<negation<is_eigen_dense_map<T>>, is_template_base_of<Eigen::PlainObjectBase, T>>;
+template <typename T>
+using is_eigen_sparse = is_template_base_of<Eigen::SparseMatrixBase, T>;
+// Test for objects inheriting from EigenBase<Derived> that aren't captured by the above.  This
+// basically covers anything that can be assigned to a dense matrix but that don't have a typical
+// matrix data layout that can be copied from their .data().  For example, DiagonalMatrix and
+// SelfAdjointView fall into this category.
+template <typename T>
+using is_eigen_other
+    = all_of<is_template_base_of<Eigen::EigenBase, T>,
+             negation<any_of<is_eigen_dense_map<T>, is_eigen_dense_plain<T>, is_eigen_sparse<T>>>>;
+
+// Captures numpy/eigen conformability status (returned by EigenProps::conformable()):
+template <bool EigenRowMajor>
+struct EigenConformable {
+    bool conformable = false;
+    EigenIndex rows = 0, cols = 0;
+    EigenDStride stride{0, 0};    // Only valid if negativestrides is false!
+    bool negativestrides = false; // If true, do not use stride!
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    EigenConformable(bool fits = false) : conformable{fits} {}
+    // Matrix type:
+    EigenConformable(EigenIndex r, EigenIndex c, EigenIndex rstride, EigenIndex cstride)
+        : conformable{true}, rows{r}, cols{c},
+          // TODO: when Eigen bug #747 is fixed, remove the tests for non-negativity.
+          // http://eigen.tuxfamily.org/bz/show_bug.cgi?id=747
+          stride{EigenRowMajor ? (rstride > 0 ? rstride : 0)
+                               : (cstride > 0 ? cstride : 0) /* outer stride */,
+                 EigenRowMajor ? (cstride > 0 ? cstride : 0)
+                               : (rstride > 0 ? rstride : 0) /* inner stride */},
+          negativestrides{rstride < 0 || cstride < 0} {}
+    // Vector type:
+    EigenConformable(EigenIndex r, EigenIndex c, EigenIndex stride)
+        : EigenConformable(r, c, r == 1 ? c * stride : stride, c == 1 ? r : r * stride) {}
+
+    template <typename props>
+    bool stride_compatible() const {
+        // To have compatible strides, we need (on both dimensions) one of fully dynamic strides,
+        // matching strides, or a dimension size of 1 (in which case the stride value is
+        // irrelevant). Alternatively, if any dimension size is 0, the strides are not relevant
+        // (and numpy ≥ 1.23 sets the strides to 0 in that case, so we need to check explicitly).
+        if (negativestrides) {
+            return false;
+        }
+        if (rows == 0 || cols == 0) {
+            return true;
+        }
+        return (props::inner_stride == Eigen::Dynamic || props::inner_stride == stride.inner()
+                || (EigenRowMajor ? cols : rows) == 1)
+               && (props::outer_stride == Eigen::Dynamic || props::outer_stride == stride.outer()
+                   || (EigenRowMajor ? rows : cols) == 1);
+    }
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator bool() const { return conformable; }
+};
+
+template <typename Type>
+struct eigen_extract_stride {
+    using type = Type;
+};
+template <typename PlainObjectType, int MapOptions, typename StrideType>
+struct eigen_extract_stride<Eigen::Map<PlainObjectType, MapOptions, StrideType>> {
+    using type = StrideType;
+};
+template <typename PlainObjectType, int Options, typename StrideType>
+struct eigen_extract_stride<Eigen::Ref<PlainObjectType, Options, StrideType>> {
+    using type = StrideType;
+};
+
+// Helper struct for extracting information from an Eigen type
+template <typename Type_>
+struct EigenProps {
+    using Type = Type_;
+    using Scalar = typename Type::Scalar;
+    using StrideType = typename eigen_extract_stride<Type>::type;
+    static constexpr EigenIndex rows = Type::RowsAtCompileTime, cols = Type::ColsAtCompileTime,
+                                size = Type::SizeAtCompileTime;
+    static constexpr bool row_major = Type::IsRowMajor,
+                          vector
+                          = Type::IsVectorAtCompileTime, // At least one dimension has fixed size 1
+        fixed_rows = rows != Eigen::Dynamic, fixed_cols = cols != Eigen::Dynamic,
+                          fixed = size != Eigen::Dynamic, // Fully-fixed size
+        dynamic = !fixed_rows && !fixed_cols;             // Fully-dynamic size
+
+    template <EigenIndex i, EigenIndex ifzero>
+    using if_zero = std::integral_constant<EigenIndex, i == 0 ? ifzero : i>;
+    static constexpr EigenIndex inner_stride
+        = if_zero<StrideType::InnerStrideAtCompileTime, 1>::value,
+        outer_stride = if_zero < StrideType::OuterStrideAtCompileTime,
+        vector      ? size
+        : row_major ? cols
+                    : rows > ::value;
+    static constexpr bool dynamic_stride
+        = inner_stride == Eigen::Dynamic && outer_stride == Eigen::Dynamic;
+    static constexpr bool requires_row_major
+        = !dynamic_stride && !vector && (row_major ? inner_stride : outer_stride) == 1;
+    static constexpr bool requires_col_major
+        = !dynamic_stride && !vector && (row_major ? outer_stride : inner_stride) == 1;
+
+    // Takes an input array and determines whether we can make it fit into the Eigen type.  If
+    // the array is a vector, we attempt to fit it into either an Eigen 1xN or Nx1 vector
+    // (preferring the latter if it will fit in either, i.e. for a fully dynamic matrix type).
+    static EigenConformable<row_major> conformable(const array &a) {
+        const auto dims = a.ndim();
+        if (dims < 1 || dims > 2) {
+            return false;
+        }
+
+        if (dims == 2) { // Matrix type: require exact match (or dynamic)
+
+            EigenIndex np_rows = a.shape(0), np_cols = a.shape(1),
+                       np_rstride = a.strides(0) / static_cast<ssize_t>(sizeof(Scalar)),
+                       np_cstride = a.strides(1) / static_cast<ssize_t>(sizeof(Scalar));
+            if ((fixed_rows && np_rows != rows) || (fixed_cols && np_cols != cols)) {
+                return false;
+            }
+
+            return {np_rows, np_cols, np_rstride, np_cstride};
+        }
+
+        // Otherwise we're storing an n-vector.  Only one of the strides will be used, but
+        // whichever is used, we want the (single) numpy stride value.
+        const EigenIndex n = a.shape(0),
+                         stride = a.strides(0) / static_cast<ssize_t>(sizeof(Scalar));
+
+        if (vector) { // Eigen type is a compile-time vector
+            if (fixed && size != n) {
+                return false; // Vector size mismatch
+            }
+            return {rows == 1 ? 1 : n, cols == 1 ? 1 : n, stride};
+        }
+        if (fixed) {
+            // The type has a fixed size, but is not a vector: abort
+            return false;
+        }
+        if (fixed_cols) {
+            // Since this isn't a vector, cols must be != 1.  We allow this only if it exactly
+            // equals the number of elements (rows is Dynamic, and so 1 row is allowed).
+            if (cols != n) {
+                return false;
+            }
+            return {1, n, stride};
+        } // Otherwise it's either fully dynamic, or column dynamic; both become a column vector
+        if (fixed_rows && rows != n) {
+            return false;
+        }
+        return {n, 1, stride};
+    }
+
+    static constexpr bool show_writeable
+        = is_eigen_dense_map<Type>::value && is_eigen_mutable_map<Type>::value;
+    static constexpr bool show_order = is_eigen_dense_map<Type>::value;
+    static constexpr bool show_c_contiguous = show_order && requires_row_major;
+    static constexpr bool show_f_contiguous
+        = !show_c_contiguous && show_order && requires_col_major;
+
+    static constexpr auto descriptor
+        = const_name("numpy.ndarray[") + npy_format_descriptor<Scalar>::name + const_name("[")
+          + const_name<fixed_rows>(const_name<(size_t) rows>(), const_name("m")) + const_name(", ")
+          + const_name<fixed_cols>(const_name<(size_t) cols>(), const_name("n")) + const_name("]")
+          +
+          // For a reference type (e.g. Ref<MatrixXd>) we have other constraints that might need to
+          // be satisfied: writeable=True (for a mutable reference), and, depending on the map's
+          // stride options, possibly f_contiguous or c_contiguous.  We include them in the
+          // descriptor output to provide some hint as to why a TypeError is occurring (otherwise
+          // it can be confusing to see that a function accepts a 'numpy.ndarray[float64[3,2]]' and
+          // an error message that you *gave* a numpy.ndarray of the right type and dimensions.
+          const_name<show_writeable>(", flags.writeable", "")
+          + const_name<show_c_contiguous>(", flags.c_contiguous", "")
+          + const_name<show_f_contiguous>(", flags.f_contiguous", "") + const_name("]");
+};
+
+// Casts an Eigen type to numpy array.  If given a base, the numpy array references the src data,
+// otherwise it'll make a copy.  writeable lets you turn off the writeable flag for the array.
+template <typename props>
+handle
+eigen_array_cast(typename props::Type const &src, handle base = handle(), bool writeable = true) {
+    constexpr ssize_t elem_size = sizeof(typename props::Scalar);
+    array a;
+    if (props::vector) {
+        a = array({src.size()}, {elem_size * src.innerStride()}, src.data(), base);
+    } else {
+        a = array({src.rows(), src.cols()},
+                  {elem_size * src.rowStride(), elem_size * src.colStride()},
+                  src.data(),
+                  base);
+    }
+
+    if (!writeable) {
+        array_proxy(a.ptr())->flags &= ~detail::npy_api::NPY_ARRAY_WRITEABLE_;
+    }
+
+    return a.release();
+}
+
+// Takes an lvalue ref to some Eigen type and a (python) base object, creating a numpy array that
+// reference the Eigen object's data with `base` as the python-registered base class (if omitted,
+// the base will be set to None, and lifetime management is up to the caller).  The numpy array is
+// non-writeable if the given type is const.
+template <typename props, typename Type>
+handle eigen_ref_array(Type &src, handle parent = none()) {
+    // none here is to get past array's should-we-copy detection, which currently always
+    // copies when there is no base.  Setting the base to None should be harmless.
+    return eigen_array_cast<props>(src, parent, !std::is_const<Type>::value);
+}
+
+// Takes a pointer to some dense, plain Eigen type, builds a capsule around it, then returns a
+// numpy array that references the encapsulated data with a python-side reference to the capsule to
+// tie its destruction to that of any dependent python objects.  Const-ness is determined by
+// whether or not the Type of the pointer given is const.
+template <typename props, typename Type, typename = enable_if_t<is_eigen_dense_plain<Type>::value>>
+handle eigen_encapsulate(Type *src) {
+    capsule base(src, [](void *o) { delete static_cast<Type *>(o); });
+    return eigen_ref_array<props>(*src, base);
+}
+
+// Type caster for regular, dense matrix types (e.g. MatrixXd), but not maps/refs/etc. of dense
+// types.
+template <typename Type>
+struct type_caster<Type, enable_if_t<is_eigen_dense_plain<Type>::value>> {
+    using Scalar = typename Type::Scalar;
+    static_assert(!std::is_pointer<Scalar>::value,
+                  PYBIND11_EIGEN_MESSAGE_POINTER_TYPES_ARE_NOT_SUPPORTED);
+    using props = EigenProps<Type>;
+
+    bool load(handle src, bool convert) {
+        // If we're in no-convert mode, only load if given an array of the correct type
+        if (!convert && !isinstance<array_t<Scalar>>(src)) {
+            return false;
+        }
+
+        // Coerce into an array, but don't do type conversion yet; the copy below handles it.
+        auto buf = array::ensure(src);
+
+        if (!buf) {
+            return false;
+        }
+
+        auto dims = buf.ndim();
+        if (dims < 1 || dims > 2) {
+            return false;
+        }
+
+        auto fits = props::conformable(buf);
+        if (!fits) {
+            return false;
+        }
+
+        // Allocate the new type, then build a numpy reference into it
+        value = Type(fits.rows, fits.cols);
+        auto ref = reinterpret_steal<array>(eigen_ref_array<props>(value));
+        if (dims == 1) {
+            ref = ref.squeeze();
+        } else if (ref.ndim() == 1) {
+            buf = buf.squeeze();
+        }
+
+        int result = detail::npy_api::get().PyArray_CopyInto_(ref.ptr(), buf.ptr());
+
+        if (result < 0) { // Copy failed!
+            PyErr_Clear();
+            return false;
+        }
+
+        return true;
+    }
+
+private:
+    // Cast implementation
+    template <typename CType>
+    static handle cast_impl(CType *src, return_value_policy policy, handle parent) {
+        switch (policy) {
+            case return_value_policy::take_ownership:
+            case return_value_policy::automatic:
+                return eigen_encapsulate<props>(src);
+            case return_value_policy::move:
+                return eigen_encapsulate<props>(new CType(std::move(*src)));
+            case return_value_policy::copy:
+                return eigen_array_cast<props>(*src);
+            case return_value_policy::reference:
+            case return_value_policy::automatic_reference:
+                return eigen_ref_array<props>(*src);
+            case return_value_policy::reference_internal:
+                return eigen_ref_array<props>(*src, parent);
+            default:
+                throw cast_error("unhandled return_value_policy: should not happen!");
+        };
+    }
+
+public:
+    // Normal returned non-reference, non-const value:
+    static handle cast(Type &&src, return_value_policy /* policy */, handle parent) {
+        return cast_impl(&src, return_value_policy::move, parent);
+    }
+    // If you return a non-reference const, we mark the numpy array readonly:
+    static handle cast(const Type &&src, return_value_policy /* policy */, handle parent) {
+        return cast_impl(&src, return_value_policy::move, parent);
+    }
+    // lvalue reference return; default (automatic) becomes copy
+    static handle cast(Type &src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::copy;
+        }
+        return cast_impl(&src, policy, parent);
+    }
+    // const lvalue reference return; default (automatic) becomes copy
+    static handle cast(const Type &src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::copy;
+        }
+        return cast(&src, policy, parent);
+    }
+    // non-const pointer return
+    static handle cast(Type *src, return_value_policy policy, handle parent) {
+        return cast_impl(src, policy, parent);
+    }
+    // const pointer return
+    static handle cast(const Type *src, return_value_policy policy, handle parent) {
+        return cast_impl(src, policy, parent);
+    }
+
+    static constexpr auto name = props::descriptor;
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator Type *() { return &value; }
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator Type &() { return value; }
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator Type &&() && { return std::move(value); }
+    template <typename T>
+    using cast_op_type = movable_cast_op_type<T>;
+
+private:
+    Type value;
+};
+
+// Base class for casting reference/map/block/etc. objects back to python.
+template <typename MapType>
+struct eigen_map_caster {
+    static_assert(!std::is_pointer<typename MapType::Scalar>::value,
+                  PYBIND11_EIGEN_MESSAGE_POINTER_TYPES_ARE_NOT_SUPPORTED);
+
+private:
+    using props = EigenProps<MapType>;
+
+public:
+    // Directly referencing a ref/map's data is a bit dangerous (whatever the map/ref points to has
+    // to stay around), but we'll allow it under the assumption that you know what you're doing
+    // (and have an appropriate keep_alive in place).  We return a numpy array pointing directly at
+    // the ref's data (The numpy array ends up read-only if the ref was to a const matrix type.)
+    // Note that this means you need to ensure you don't destroy the object in some other way (e.g.
+    // with an appropriate keep_alive, or with a reference to a statically allocated matrix).
+    static handle cast(const MapType &src, return_value_policy policy, handle parent) {
+        switch (policy) {
+            case return_value_policy::copy:
+                return eigen_array_cast<props>(src);
+            case return_value_policy::reference_internal:
+                return eigen_array_cast<props>(src, parent, is_eigen_mutable_map<MapType>::value);
+            case return_value_policy::reference:
+            case return_value_policy::automatic:
+            case return_value_policy::automatic_reference:
+                return eigen_array_cast<props>(src, none(), is_eigen_mutable_map<MapType>::value);
+            default:
+                // move, take_ownership don't make any sense for a ref/map:
+                pybind11_fail("Invalid return_value_policy for Eigen Map/Ref/Block type");
+        }
+    }
+
+    static constexpr auto name = props::descriptor;
+
+    // Explicitly delete these: support python -> C++ conversion on these (i.e. these can be return
+    // types but not bound arguments).  We still provide them (with an explicitly delete) so that
+    // you end up here if you try anyway.
+    bool load(handle, bool) = delete;
+    operator MapType() = delete;
+    template <typename>
+    using cast_op_type = MapType;
+};
+
+// We can return any map-like object (but can only load Refs, specialized next):
+template <typename Type>
+struct type_caster<Type, enable_if_t<is_eigen_dense_map<Type>::value>> : eigen_map_caster<Type> {};
+
+// Loader for Ref<...> arguments.  See the documentation for info on how to make this work without
+// copying (it requires some extra effort in many cases).
+template <typename PlainObjectType, typename StrideType>
+struct type_caster<
+    Eigen::Ref<PlainObjectType, 0, StrideType>,
+    enable_if_t<is_eigen_dense_map<Eigen::Ref<PlainObjectType, 0, StrideType>>::value>>
+    : public eigen_map_caster<Eigen::Ref<PlainObjectType, 0, StrideType>> {
+private:
+    using Type = Eigen::Ref<PlainObjectType, 0, StrideType>;
+    using props = EigenProps<Type>;
+    using Scalar = typename props::Scalar;
+    static_assert(!std::is_pointer<Scalar>::value,
+                  PYBIND11_EIGEN_MESSAGE_POINTER_TYPES_ARE_NOT_SUPPORTED);
+    using MapType = Eigen::Map<PlainObjectType, 0, StrideType>;
+    using Array
+        = array_t<Scalar,
+                  array::forcecast
+                      | ((props::row_major ? props::inner_stride : props::outer_stride) == 1
+                             ? array::c_style
+                         : (props::row_major ? props::outer_stride : props::inner_stride) == 1
+                             ? array::f_style
+                             : 0)>;
+    static constexpr bool need_writeable = is_eigen_mutable_map<Type>::value;
+    // Delay construction (these have no default constructor)
+    std::unique_ptr<MapType> map;
+    std::unique_ptr<Type> ref;
+    // Our array.  When possible, this is just a numpy array pointing to the source data, but
+    // sometimes we can't avoid copying (e.g. input is not a numpy array at all, has an
+    // incompatible layout, or is an array of a type that needs to be converted).  Using a numpy
+    // temporary (rather than an Eigen temporary) saves an extra copy when we need both type
+    // conversion and storage order conversion.  (Note that we refuse to use this temporary copy
+    // when loading an argument for a Ref<M> with M non-const, i.e. a read-write reference).
+    Array copy_or_ref;
+
+public:
+    bool load(handle src, bool convert) {
+        // First check whether what we have is already an array of the right type.  If not, we
+        // can't avoid a copy (because the copy is also going to do type conversion).
+        bool need_copy = !isinstance<Array>(src);
+
+        EigenConformable<props::row_major> fits;
+        if (!need_copy) {
+            // We don't need a converting copy, but we also need to check whether the strides are
+            // compatible with the Ref's stride requirements
+            auto aref = reinterpret_borrow<Array>(src);
+
+            if (aref && (!need_writeable || aref.writeable())) {
+                fits = props::conformable(aref);
+                if (!fits) {
+                    return false; // Incompatible dimensions
+                }
+                if (!fits.template stride_compatible<props>()) {
+                    need_copy = true;
+                } else {
+                    copy_or_ref = std::move(aref);
+                }
+            } else {
+                need_copy = true;
+            }
+        }
+
+        if (need_copy) {
+            // We need to copy: If we need a mutable reference, or we're not supposed to convert
+            // (either because we're in the no-convert overload pass, or because we're explicitly
+            // instructed not to copy (via `py::arg().noconvert()`) we have to fail loading.
+            if (!convert || need_writeable) {
+                return false;
+            }
+
+            Array copy = Array::ensure(src);
+            if (!copy) {
+                return false;
+            }
+            fits = props::conformable(copy);
+            if (!fits || !fits.template stride_compatible<props>()) {
+                return false;
+            }
+            copy_or_ref = std::move(copy);
+            loader_life_support::add_patient(copy_or_ref);
+        }
+
+        ref.reset();
+        map.reset(new MapType(data(copy_or_ref),
+                              fits.rows,
+                              fits.cols,
+                              make_stride(fits.stride.outer(), fits.stride.inner())));
+        ref.reset(new Type(*map));
+
+        return true;
+    }
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator Type *() { return ref.get(); }
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator Type &() { return *ref; }
+    template <typename _T>
+    using cast_op_type = pybind11::detail::cast_op_type<_T>;
+
+private:
+    template <typename T = Type, enable_if_t<is_eigen_mutable_map<T>::value, int> = 0>
+    Scalar *data(Array &a) {
+        return a.mutable_data();
+    }
+
+    template <typename T = Type, enable_if_t<!is_eigen_mutable_map<T>::value, int> = 0>
+    const Scalar *data(Array &a) {
+        return a.data();
+    }
+
+    // Attempt to figure out a constructor of `Stride` that will work.
+    // If both strides are fixed, use a default constructor:
+    template <typename S>
+    using stride_ctor_default = bool_constant<S::InnerStrideAtCompileTime != Eigen::Dynamic
+                                              && S::OuterStrideAtCompileTime != Eigen::Dynamic
+                                              && std::is_default_constructible<S>::value>;
+    // Otherwise, if there is a two-index constructor, assume it is (outer,inner) like
+    // Eigen::Stride, and use it:
+    template <typename S>
+    using stride_ctor_dual
+        = bool_constant<!stride_ctor_default<S>::value
+                        && std::is_constructible<S, EigenIndex, EigenIndex>::value>;
+    // Otherwise, if there is a one-index constructor, and just one of the strides is dynamic, use
+    // it (passing whichever stride is dynamic).
+    template <typename S>
+    using stride_ctor_outer
+        = bool_constant<!any_of<stride_ctor_default<S>, stride_ctor_dual<S>>::value
+                        && S::OuterStrideAtCompileTime == Eigen::Dynamic
+                        && S::InnerStrideAtCompileTime != Eigen::Dynamic
+                        && std::is_constructible<S, EigenIndex>::value>;
+    template <typename S>
+    using stride_ctor_inner
+        = bool_constant<!any_of<stride_ctor_default<S>, stride_ctor_dual<S>>::value
+                        && S::InnerStrideAtCompileTime == Eigen::Dynamic
+                        && S::OuterStrideAtCompileTime != Eigen::Dynamic
+                        && std::is_constructible<S, EigenIndex>::value>;
+
+    template <typename S = StrideType, enable_if_t<stride_ctor_default<S>::value, int> = 0>
+    static S make_stride(EigenIndex, EigenIndex) {
+        return S();
+    }
+    template <typename S = StrideType, enable_if_t<stride_ctor_dual<S>::value, int> = 0>
+    static S make_stride(EigenIndex outer, EigenIndex inner) {
+        return S(outer, inner);
+    }
+    template <typename S = StrideType, enable_if_t<stride_ctor_outer<S>::value, int> = 0>
+    static S make_stride(EigenIndex outer, EigenIndex) {
+        return S(outer);
+    }
+    template <typename S = StrideType, enable_if_t<stride_ctor_inner<S>::value, int> = 0>
+    static S make_stride(EigenIndex, EigenIndex inner) {
+        return S(inner);
+    }
+};
+
+// type_caster for special matrix types (e.g. DiagonalMatrix), which are EigenBase, but not
+// EigenDense (i.e. they don't have a data(), at least not with the usual matrix layout).
+// load() is not supported, but we can cast them into the python domain by first copying to a
+// regular Eigen::Matrix, then casting that.
+template <typename Type>
+struct type_caster<Type, enable_if_t<is_eigen_other<Type>::value>> {
+    static_assert(!std::is_pointer<typename Type::Scalar>::value,
+                  PYBIND11_EIGEN_MESSAGE_POINTER_TYPES_ARE_NOT_SUPPORTED);
+
+protected:
+    using Matrix
+        = Eigen::Matrix<typename Type::Scalar, Type::RowsAtCompileTime, Type::ColsAtCompileTime>;
+    using props = EigenProps<Matrix>;
+
+public:
+    static handle cast(const Type &src, return_value_policy /* policy */, handle /* parent */) {
+        handle h = eigen_encapsulate<props>(new Matrix(src));
+        return h;
+    }
+    static handle cast(const Type *src, return_value_policy policy, handle parent) {
+        return cast(*src, policy, parent);
+    }
+
+    static constexpr auto name = props::descriptor;
+
+    // Explicitly delete these: support python -> C++ conversion on these (i.e. these can be return
+    // types but not bound arguments).  We still provide them (with an explicitly delete) so that
+    // you end up here if you try anyway.
+    bool load(handle, bool) = delete;
+    operator Type() = delete;
+    template <typename>
+    using cast_op_type = Type;
+};
+
+template <typename Type>
+struct type_caster<Type, enable_if_t<is_eigen_sparse<Type>::value>> {
+    using Scalar = typename Type::Scalar;
+    static_assert(!std::is_pointer<Scalar>::value,
+                  PYBIND11_EIGEN_MESSAGE_POINTER_TYPES_ARE_NOT_SUPPORTED);
+    using StorageIndex = remove_reference_t<decltype(*std::declval<Type>().outerIndexPtr())>;
+    using Index = typename Type::Index;
+    static constexpr bool rowMajor = Type::IsRowMajor;
+
+    bool load(handle src, bool) {
+        if (!src) {
+            return false;
+        }
+
+        auto obj = reinterpret_borrow<object>(src);
+        object sparse_module = module_::import("scipy.sparse");
+        object matrix_type = sparse_module.attr(rowMajor ? "csr_matrix" : "csc_matrix");
+
+        if (!type::handle_of(obj).is(matrix_type)) {
+            try {
+                obj = matrix_type(obj);
+            } catch (const error_already_set &) {
+                return false;
+            }
+        }
+
+        auto values = array_t<Scalar>((object) obj.attr("data"));
+        auto innerIndices = array_t<StorageIndex>((object) obj.attr("indices"));
+        auto outerIndices = array_t<StorageIndex>((object) obj.attr("indptr"));
+        auto shape = pybind11::tuple((pybind11::object) obj.attr("shape"));
+        auto nnz = obj.attr("nnz").cast<Index>();
+
+        if (!values || !innerIndices || !outerIndices) {
+            return false;
+        }
+
+        value = EigenMapSparseMatrix<Scalar,
+                                     Type::Flags &(Eigen::RowMajor | Eigen::ColMajor),
+                                     StorageIndex>(shape[0].cast<Index>(),
+                                                   shape[1].cast<Index>(),
+                                                   std::move(nnz),
+                                                   outerIndices.mutable_data(),
+                                                   innerIndices.mutable_data(),
+                                                   values.mutable_data());
+
+        return true;
+    }
+
+    static handle cast(const Type &src, return_value_policy /* policy */, handle /* parent */) {
+        const_cast<Type &>(src).makeCompressed();
+
+        object matrix_type
+            = module_::import("scipy.sparse").attr(rowMajor ? "csr_matrix" : "csc_matrix");
+
+        array data(src.nonZeros(), src.valuePtr());
+        array outerIndices((rowMajor ? src.rows() : src.cols()) + 1, src.outerIndexPtr());
+        array innerIndices(src.nonZeros(), src.innerIndexPtr());
+
+        return matrix_type(pybind11::make_tuple(
+                               std::move(data), std::move(innerIndices), std::move(outerIndices)),
+                           pybind11::make_tuple(src.rows(), src.cols()))
+            .release();
+    }
+
+    PYBIND11_TYPE_CASTER(Type,
+                         const_name<(Type::IsRowMajor) != 0>("scipy.sparse.csr_matrix[",
+                                                             "scipy.sparse.csc_matrix[")
+                             + npy_format_descriptor<Scalar>::name + const_name("]"));
+};
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/eigen/tensor.h

@@ -0,0 +1,516 @@
+/*
+    pybind11/eigen/tensor.h: Transparent conversion for Eigen tensors
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "../numpy.h"
+#include "common.h"
+
+#if defined(__GNUC__) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+static_assert(__GNUC__ > 5, "Eigen Tensor support in pybind11 requires GCC > 5.0");
+#endif
+
+// Disable warnings for Eigen
+PYBIND11_WARNING_PUSH
+PYBIND11_WARNING_DISABLE_MSVC(4554)
+PYBIND11_WARNING_DISABLE_MSVC(4127)
+#if defined(__MINGW32__)
+PYBIND11_WARNING_DISABLE_GCC("-Wmaybe-uninitialized")
+#endif
+
+#include <unsupported/Eigen/CXX11/Tensor>
+
+PYBIND11_WARNING_POP
+
+static_assert(EIGEN_VERSION_AT_LEAST(3, 3, 0),
+              "Eigen Tensor support in pybind11 requires Eigen >= 3.3.0");
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+PYBIND11_WARNING_DISABLE_MSVC(4127)
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+inline bool is_tensor_aligned(const void *data) {
+    return (reinterpret_cast<std::size_t>(data) % EIGEN_DEFAULT_ALIGN_BYTES) == 0;
+}
+
+template <typename T>
+constexpr int compute_array_flag_from_tensor() {
+    static_assert((static_cast<int>(T::Layout) == static_cast<int>(Eigen::RowMajor))
+                      || (static_cast<int>(T::Layout) == static_cast<int>(Eigen::ColMajor)),
+                  "Layout must be row or column major");
+    return (static_cast<int>(T::Layout) == static_cast<int>(Eigen::RowMajor)) ? array::c_style
+                                                                              : array::f_style;
+}
+
+template <typename T>
+struct eigen_tensor_helper {};
+
+template <typename Scalar_, int NumIndices_, int Options_, typename IndexType>
+struct eigen_tensor_helper<Eigen::Tensor<Scalar_, NumIndices_, Options_, IndexType>> {
+    using Type = Eigen::Tensor<Scalar_, NumIndices_, Options_, IndexType>;
+    using ValidType = void;
+
+    static Eigen::DSizes<typename Type::Index, Type::NumIndices> get_shape(const Type &f) {
+        return f.dimensions();
+    }
+
+    static constexpr bool
+    is_correct_shape(const Eigen::DSizes<typename Type::Index, Type::NumIndices> & /*shape*/) {
+        return true;
+    }
+
+    template <typename T>
+    struct helper {};
+
+    template <size_t... Is>
+    struct helper<index_sequence<Is...>> {
+        static constexpr auto value = concat(const_name(((void) Is, "?"))...);
+    };
+
+    static constexpr auto dimensions_descriptor
+        = helper<decltype(make_index_sequence<Type::NumIndices>())>::value;
+
+    template <typename... Args>
+    static Type *alloc(Args &&...args) {
+        return new Type(std::forward<Args>(args)...);
+    }
+
+    static void free(Type *tensor) { delete tensor; }
+};
+
+template <typename Scalar_, typename std::ptrdiff_t... Indices, int Options_, typename IndexType>
+struct eigen_tensor_helper<
+    Eigen::TensorFixedSize<Scalar_, Eigen::Sizes<Indices...>, Options_, IndexType>> {
+    using Type = Eigen::TensorFixedSize<Scalar_, Eigen::Sizes<Indices...>, Options_, IndexType>;
+    using ValidType = void;
+
+    static constexpr Eigen::DSizes<typename Type::Index, Type::NumIndices>
+    get_shape(const Type & /*f*/) {
+        return get_shape();
+    }
+
+    static constexpr Eigen::DSizes<typename Type::Index, Type::NumIndices> get_shape() {
+        return Eigen::DSizes<typename Type::Index, Type::NumIndices>(Indices...);
+    }
+
+    static bool
+    is_correct_shape(const Eigen::DSizes<typename Type::Index, Type::NumIndices> &shape) {
+        return get_shape() == shape;
+    }
+
+    static constexpr auto dimensions_descriptor = concat(const_name<Indices>()...);
+
+    template <typename... Args>
+    static Type *alloc(Args &&...args) {
+        Eigen::aligned_allocator<Type> allocator;
+        return ::new (allocator.allocate(1)) Type(std::forward<Args>(args)...);
+    }
+
+    static void free(Type *tensor) {
+        Eigen::aligned_allocator<Type> allocator;
+        tensor->~Type();
+        allocator.deallocate(tensor, 1);
+    }
+};
+
+template <typename Type, bool ShowDetails, bool NeedsWriteable = false>
+struct get_tensor_descriptor {
+    static constexpr auto details
+        = const_name<NeedsWriteable>(", flags.writeable", "")
+          + const_name<static_cast<int>(Type::Layout) == static_cast<int>(Eigen::RowMajor)>(
+              ", flags.c_contiguous", ", flags.f_contiguous");
+    static constexpr auto value
+        = const_name("numpy.ndarray[") + npy_format_descriptor<typename Type::Scalar>::name
+          + const_name("[") + eigen_tensor_helper<remove_cv_t<Type>>::dimensions_descriptor
+          + const_name("]") + const_name<ShowDetails>(details, const_name("")) + const_name("]");
+};
+
+// When EIGEN_AVOID_STL_ARRAY is defined, Eigen::DSizes<T, 0> does not have the begin() member
+// function. Falling back to a simple loop works around this issue.
+//
+// We need to disable the type-limits warning for the inner loop when size = 0.
+
+PYBIND11_WARNING_PUSH
+PYBIND11_WARNING_DISABLE_GCC("-Wtype-limits")
+
+template <typename T, int size>
+std::vector<T> convert_dsizes_to_vector(const Eigen::DSizes<T, size> &arr) {
+    std::vector<T> result(size);
+
+    for (size_t i = 0; i < size; i++) {
+        result[i] = arr[i];
+    }
+
+    return result;
+}
+
+template <typename T, int size>
+Eigen::DSizes<T, size> get_shape_for_array(const array &arr) {
+    Eigen::DSizes<T, size> result;
+    const T *shape = arr.shape();
+    for (size_t i = 0; i < size; i++) {
+        result[i] = shape[i];
+    }
+
+    return result;
+}
+
+PYBIND11_WARNING_POP
+
+template <typename Type>
+struct type_caster<Type, typename eigen_tensor_helper<Type>::ValidType> {
+    static_assert(!std::is_pointer<typename Type::Scalar>::value,
+                  PYBIND11_EIGEN_MESSAGE_POINTER_TYPES_ARE_NOT_SUPPORTED);
+    using Helper = eigen_tensor_helper<Type>;
+    static constexpr auto temp_name = get_tensor_descriptor<Type, false>::value;
+    PYBIND11_TYPE_CASTER(Type, temp_name);
+
+    bool load(handle src, bool convert) {
+        if (!convert) {
+            if (!isinstance<array>(src)) {
+                return false;
+            }
+            array temp = array::ensure(src);
+            if (!temp) {
+                return false;
+            }
+
+            if (!temp.dtype().is(dtype::of<typename Type::Scalar>())) {
+                return false;
+            }
+        }
+
+        array_t<typename Type::Scalar, compute_array_flag_from_tensor<Type>()> arr(
+            reinterpret_borrow<object>(src));
+
+        if (arr.ndim() != Type::NumIndices) {
+            return false;
+        }
+        auto shape = get_shape_for_array<typename Type::Index, Type::NumIndices>(arr);
+
+        if (!Helper::is_correct_shape(shape)) {
+            return false;
+        }
+
+#if EIGEN_VERSION_AT_LEAST(3, 4, 0)
+        auto data_pointer = arr.data();
+#else
+        // Handle Eigen bug
+        auto data_pointer = const_cast<typename Type::Scalar *>(arr.data());
+#endif
+
+        if (is_tensor_aligned(arr.data())) {
+            value = Eigen::TensorMap<const Type, Eigen::Aligned>(data_pointer, shape);
+        } else {
+            value = Eigen::TensorMap<const Type>(data_pointer, shape);
+        }
+
+        return true;
+    }
+
+    static handle cast(Type &&src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::reference
+            || policy == return_value_policy::reference_internal) {
+            pybind11_fail("Cannot use a reference return value policy for an rvalue");
+        }
+        return cast_impl(&src, return_value_policy::move, parent);
+    }
+
+    static handle cast(const Type &&src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::reference
+            || policy == return_value_policy::reference_internal) {
+            pybind11_fail("Cannot use a reference return value policy for an rvalue");
+        }
+        return cast_impl(&src, return_value_policy::move, parent);
+    }
+
+    static handle cast(Type &src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::copy;
+        }
+        return cast_impl(&src, policy, parent);
+    }
+
+    static handle cast(const Type &src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::copy;
+        }
+        return cast(&src, policy, parent);
+    }
+
+    static handle cast(Type *src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic) {
+            policy = return_value_policy::take_ownership;
+        } else if (policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::reference;
+        }
+        return cast_impl(src, policy, parent);
+    }
+
+    static handle cast(const Type *src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic) {
+            policy = return_value_policy::take_ownership;
+        } else if (policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::reference;
+        }
+        return cast_impl(src, policy, parent);
+    }
+
+    template <typename C>
+    static handle cast_impl(C *src, return_value_policy policy, handle parent) {
+        object parent_object;
+        bool writeable = false;
+        switch (policy) {
+            case return_value_policy::move:
+                if (std::is_const<C>::value) {
+                    pybind11_fail("Cannot move from a constant reference");
+                }
+
+                src = Helper::alloc(std::move(*src));
+
+                parent_object
+                    = capsule(src, [](void *ptr) { Helper::free(reinterpret_cast<Type *>(ptr)); });
+                writeable = true;
+                break;
+
+            case return_value_policy::take_ownership:
+                if (std::is_const<C>::value) {
+                    // This cast is ugly, and might be UB in some cases, but we don't have an
+                    // alternative here as we must free that memory
+                    Helper::free(const_cast<Type *>(src));
+                    pybind11_fail("Cannot take ownership of a const reference");
+                }
+
+                parent_object
+                    = capsule(src, [](void *ptr) { Helper::free(reinterpret_cast<Type *>(ptr)); });
+                writeable = true;
+                break;
+
+            case return_value_policy::copy:
+                writeable = true;
+                break;
+
+            case return_value_policy::reference:
+                parent_object = none();
+                writeable = !std::is_const<C>::value;
+                break;
+
+            case return_value_policy::reference_internal:
+                // Default should do the right thing
+                if (!parent) {
+                    pybind11_fail("Cannot use reference internal when there is no parent");
+                }
+                parent_object = reinterpret_borrow<object>(parent);
+                writeable = !std::is_const<C>::value;
+                break;
+
+            default:
+                pybind11_fail("pybind11 bug in eigen.h, please file a bug report");
+        }
+
+        auto result = array_t<typename Type::Scalar, compute_array_flag_from_tensor<Type>()>(
+            convert_dsizes_to_vector(Helper::get_shape(*src)), src->data(), parent_object);
+
+        if (!writeable) {
+            array_proxy(result.ptr())->flags &= ~detail::npy_api::NPY_ARRAY_WRITEABLE_;
+        }
+
+        return result.release();
+    }
+};
+
+template <typename StoragePointerType,
+          bool needs_writeable,
+          enable_if_t<!needs_writeable, bool> = true>
+StoragePointerType get_array_data_for_type(array &arr) {
+#if EIGEN_VERSION_AT_LEAST(3, 4, 0)
+    return reinterpret_cast<StoragePointerType>(arr.data());
+#else
+    // Handle Eigen bug
+    return reinterpret_cast<StoragePointerType>(const_cast<void *>(arr.data()));
+#endif
+}
+
+template <typename StoragePointerType,
+          bool needs_writeable,
+          enable_if_t<needs_writeable, bool> = true>
+StoragePointerType get_array_data_for_type(array &arr) {
+    return reinterpret_cast<StoragePointerType>(arr.mutable_data());
+}
+
+template <typename T, typename = void>
+struct get_storage_pointer_type;
+
+template <typename MapType>
+struct get_storage_pointer_type<MapType, void_t<typename MapType::StoragePointerType>> {
+    using SPT = typename MapType::StoragePointerType;
+};
+
+template <typename MapType>
+struct get_storage_pointer_type<MapType, void_t<typename MapType::PointerArgType>> {
+    using SPT = typename MapType::PointerArgType;
+};
+
+template <typename Type, int Options>
+struct type_caster<Eigen::TensorMap<Type, Options>,
+                   typename eigen_tensor_helper<remove_cv_t<Type>>::ValidType> {
+    static_assert(!std::is_pointer<typename Type::Scalar>::value,
+                  PYBIND11_EIGEN_MESSAGE_POINTER_TYPES_ARE_NOT_SUPPORTED);
+    using MapType = Eigen::TensorMap<Type, Options>;
+    using Helper = eigen_tensor_helper<remove_cv_t<Type>>;
+
+    bool load(handle src, bool /*convert*/) {
+        // Note that we have a lot more checks here as we want to make sure to avoid copies
+        if (!isinstance<array>(src)) {
+            return false;
+        }
+        auto arr = reinterpret_borrow<array>(src);
+        if ((arr.flags() & compute_array_flag_from_tensor<Type>()) == 0) {
+            return false;
+        }
+
+        if (!arr.dtype().is(dtype::of<typename Type::Scalar>())) {
+            return false;
+        }
+
+        if (arr.ndim() != Type::NumIndices) {
+            return false;
+        }
+
+        constexpr bool is_aligned = (Options & Eigen::Aligned) != 0;
+
+        if (is_aligned && !is_tensor_aligned(arr.data())) {
+            return false;
+        }
+
+        auto shape = get_shape_for_array<typename Type::Index, Type::NumIndices>(arr);
+
+        if (!Helper::is_correct_shape(shape)) {
+            return false;
+        }
+
+        if (needs_writeable && !arr.writeable()) {
+            return false;
+        }
+
+        auto result = get_array_data_for_type<typename get_storage_pointer_type<MapType>::SPT,
+                                              needs_writeable>(arr);
+
+        value.reset(new MapType(std::move(result), std::move(shape)));
+
+        return true;
+    }
+
+    static handle cast(MapType &&src, return_value_policy policy, handle parent) {
+        return cast_impl(&src, policy, parent);
+    }
+
+    static handle cast(const MapType &&src, return_value_policy policy, handle parent) {
+        return cast_impl(&src, policy, parent);
+    }
+
+    static handle cast(MapType &src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::copy;
+        }
+        return cast_impl(&src, policy, parent);
+    }
+
+    static handle cast(const MapType &src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::copy;
+        }
+        return cast(&src, policy, parent);
+    }
+
+    static handle cast(MapType *src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic) {
+            policy = return_value_policy::take_ownership;
+        } else if (policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::reference;
+        }
+        return cast_impl(src, policy, parent);
+    }
+
+    static handle cast(const MapType *src, return_value_policy policy, handle parent) {
+        if (policy == return_value_policy::automatic) {
+            policy = return_value_policy::take_ownership;
+        } else if (policy == return_value_policy::automatic_reference) {
+            policy = return_value_policy::reference;
+        }
+        return cast_impl(src, policy, parent);
+    }
+
+    template <typename C>
+    static handle cast_impl(C *src, return_value_policy policy, handle parent) {
+        object parent_object;
+        constexpr bool writeable = !std::is_const<C>::value;
+        switch (policy) {
+            case return_value_policy::reference:
+                parent_object = none();
+                break;
+
+            case return_value_policy::reference_internal:
+                // Default should do the right thing
+                if (!parent) {
+                    pybind11_fail("Cannot use reference internal when there is no parent");
+                }
+                parent_object = reinterpret_borrow<object>(parent);
+                break;
+
+            case return_value_policy::take_ownership:
+                delete src;
+                // fallthrough
+            default:
+                // move, take_ownership don't make any sense for a ref/map:
+                pybind11_fail("Invalid return_value_policy for Eigen Map type, must be either "
+                              "reference or reference_internal");
+        }
+
+        auto result = array_t<typename Type::Scalar, compute_array_flag_from_tensor<Type>()>(
+            convert_dsizes_to_vector(Helper::get_shape(*src)),
+            src->data(),
+            std::move(parent_object));
+
+        if (!writeable) {
+            array_proxy(result.ptr())->flags &= ~detail::npy_api::NPY_ARRAY_WRITEABLE_;
+        }
+
+        return result.release();
+    }
+
+#if EIGEN_VERSION_AT_LEAST(3, 4, 0)
+
+    static constexpr bool needs_writeable = !std::is_const<typename std::remove_pointer<
+        typename get_storage_pointer_type<MapType>::SPT>::type>::value;
+#else
+    // Handle Eigen bug
+    static constexpr bool needs_writeable = !std::is_const<Type>::value;
+#endif
+
+protected:
+    // TODO: Move to std::optional once std::optional has more support
+    std::unique_ptr<MapType> value;
+
+public:
+    static constexpr auto name = get_tensor_descriptor<Type, true, needs_writeable>::value;
+    explicit operator MapType *() { return value.get(); }
+    explicit operator MapType &() { return *value; }
+    explicit operator MapType &&() && { return std::move(*value); }
+
+    template <typename T_>
+    using cast_op_type = ::pybind11::detail::movable_cast_op_type<T_>;
+};
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/embed.h

@@ -0,0 +1,316 @@
+/*
+    pybind11/embed.h: Support for embedding the interpreter
+
+    Copyright (c) 2017 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+#include "eval.h"
+
+#include <memory>
+#include <vector>
+
+#if defined(PYPY_VERSION)
+#    error Embedding the interpreter is not supported with PyPy
+#endif
+
+#define PYBIND11_EMBEDDED_MODULE_IMPL(name)                                                       \
+    extern "C" PyObject *pybind11_init_impl_##name();                                             \
+    extern "C" PyObject *pybind11_init_impl_##name() { return pybind11_init_wrapper_##name(); }
+
+/** \rst
+    Add a new module to the table of builtins for the interpreter. Must be
+    defined in global scope. The first macro parameter is the name of the
+    module (without quotes). The second parameter is the variable which will
+    be used as the interface to add functions and classes to the module.
+
+    .. code-block:: cpp
+
+        PYBIND11_EMBEDDED_MODULE(example, m) {
+            // ... initialize functions and classes here
+            m.def("foo", []() {
+                return "Hello, World!";
+            });
+        }
+ \endrst */
+#define PYBIND11_EMBEDDED_MODULE(name, variable)                                                  \
+    static ::pybind11::module_::module_def PYBIND11_CONCAT(pybind11_module_def_, name);           \
+    static void PYBIND11_CONCAT(pybind11_init_, name)(::pybind11::module_ &);                     \
+    static PyObject PYBIND11_CONCAT(*pybind11_init_wrapper_, name)() {                            \
+        auto m = ::pybind11::module_::create_extension_module(                                    \
+            PYBIND11_TOSTRING(name), nullptr, &PYBIND11_CONCAT(pybind11_module_def_, name));      \
+        try {                                                                                     \
+            PYBIND11_CONCAT(pybind11_init_, name)(m);                                             \
+            return m.ptr();                                                                       \
+        }                                                                                         \
+        PYBIND11_CATCH_INIT_EXCEPTIONS                                                            \
+    }                                                                                             \
+    PYBIND11_EMBEDDED_MODULE_IMPL(name)                                                           \
+    ::pybind11::detail::embedded_module PYBIND11_CONCAT(pybind11_module_, name)(                  \
+        PYBIND11_TOSTRING(name), PYBIND11_CONCAT(pybind11_init_impl_, name));                     \
+    void PYBIND11_CONCAT(pybind11_init_, name)(::pybind11::module_                                \
+                                               & variable) // NOLINT(bugprone-macro-parentheses)
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/// Python 2.7/3.x compatible version of `PyImport_AppendInittab` and error checks.
+struct embedded_module {
+    using init_t = PyObject *(*) ();
+    embedded_module(const char *name, init_t init) {
+        if (Py_IsInitialized() != 0) {
+            pybind11_fail("Can't add new modules after the interpreter has been initialized");
+        }
+
+        auto result = PyImport_AppendInittab(name, init);
+        if (result == -1) {
+            pybind11_fail("Insufficient memory to add a new module");
+        }
+    }
+};
+
+struct wide_char_arg_deleter {
+    void operator()(wchar_t *ptr) const {
+        // API docs: https://docs.python.org/3/c-api/sys.html#c.Py_DecodeLocale
+        PyMem_RawFree(ptr);
+    }
+};
+
+inline wchar_t *widen_chars(const char *safe_arg) {
+    wchar_t *widened_arg = Py_DecodeLocale(safe_arg, nullptr);
+    return widened_arg;
+}
+
+inline void precheck_interpreter() {
+    if (Py_IsInitialized() != 0) {
+        pybind11_fail("The interpreter is already running");
+    }
+}
+
+#if !defined(PYBIND11_PYCONFIG_SUPPORT_PY_VERSION_HEX)
+#    define PYBIND11_PYCONFIG_SUPPORT_PY_VERSION_HEX (0x03080000)
+#endif
+
+#if PY_VERSION_HEX < PYBIND11_PYCONFIG_SUPPORT_PY_VERSION_HEX
+inline void initialize_interpreter_pre_pyconfig(bool init_signal_handlers,
+                                                int argc,
+                                                const char *const *argv,
+                                                bool add_program_dir_to_path) {
+    detail::precheck_interpreter();
+    Py_InitializeEx(init_signal_handlers ? 1 : 0);
+#    if defined(WITH_THREAD) && PY_VERSION_HEX < 0x03070000
+    PyEval_InitThreads();
+#    endif
+
+    // Before it was special-cased in python 3.8, passing an empty or null argv
+    // caused a segfault, so we have to reimplement the special case ourselves.
+    bool special_case = (argv == nullptr || argc <= 0);
+
+    const char *const empty_argv[]{"\0"};
+    const char *const *safe_argv = special_case ? empty_argv : argv;
+    if (special_case) {
+        argc = 1;
+    }
+
+    auto argv_size = static_cast<size_t>(argc);
+    // SetArgv* on python 3 takes wchar_t, so we have to convert.
+    std::unique_ptr<wchar_t *[]> widened_argv(new wchar_t *[argv_size]);
+    std::vector<std::unique_ptr<wchar_t[], detail::wide_char_arg_deleter>> widened_argv_entries;
+    widened_argv_entries.reserve(argv_size);
+    for (size_t ii = 0; ii < argv_size; ++ii) {
+        widened_argv_entries.emplace_back(detail::widen_chars(safe_argv[ii]));
+        if (!widened_argv_entries.back()) {
+            // A null here indicates a character-encoding failure or the python
+            // interpreter out of memory. Give up.
+            return;
+        }
+        widened_argv[ii] = widened_argv_entries.back().get();
+    }
+
+    auto *pysys_argv = widened_argv.get();
+
+    PySys_SetArgvEx(argc, pysys_argv, static_cast<int>(add_program_dir_to_path));
+}
+#endif
+
+PYBIND11_NAMESPACE_END(detail)
+
+#if PY_VERSION_HEX >= PYBIND11_PYCONFIG_SUPPORT_PY_VERSION_HEX
+inline void initialize_interpreter(PyConfig *config,
+                                   int argc = 0,
+                                   const char *const *argv = nullptr,
+                                   bool add_program_dir_to_path = true) {
+    detail::precheck_interpreter();
+    PyStatus status = PyConfig_SetBytesArgv(config, argc, const_cast<char *const *>(argv));
+    if (PyStatus_Exception(status) != 0) {
+        // A failure here indicates a character-encoding failure or the python
+        // interpreter out of memory. Give up.
+        PyConfig_Clear(config);
+        throw std::runtime_error(PyStatus_IsError(status) != 0 ? status.err_msg
+                                                               : "Failed to prepare CPython");
+    }
+    status = Py_InitializeFromConfig(config);
+    if (PyStatus_Exception(status) != 0) {
+        PyConfig_Clear(config);
+        throw std::runtime_error(PyStatus_IsError(status) != 0 ? status.err_msg
+                                                               : "Failed to init CPython");
+    }
+    if (add_program_dir_to_path) {
+        PyRun_SimpleString("import sys, os.path; "
+                           "sys.path.insert(0, "
+                           "os.path.abspath(os.path.dirname(sys.argv[0])) "
+                           "if sys.argv and os.path.exists(sys.argv[0]) else '')");
+    }
+    PyConfig_Clear(config);
+}
+#endif
+
+/** \rst
+    Initialize the Python interpreter. No other pybind11 or CPython API functions can be
+    called before this is done; with the exception of `PYBIND11_EMBEDDED_MODULE`. The
+    optional `init_signal_handlers` parameter can be used to skip the registration of
+    signal handlers (see the `Python documentation`_ for details). Calling this function
+    again after the interpreter has already been initialized is a fatal error.
+
+    If initializing the Python interpreter fails, then the program is terminated.  (This
+    is controlled by the CPython runtime and is an exception to pybind11's normal behavior
+    of throwing exceptions on errors.)
+
+    The remaining optional parameters, `argc`, `argv`, and `add_program_dir_to_path` are
+    used to populate ``sys.argv`` and ``sys.path``.
+    See the |PySys_SetArgvEx documentation|_ for details.
+
+    .. _Python documentation: https://docs.python.org/3/c-api/init.html#c.Py_InitializeEx
+    .. |PySys_SetArgvEx documentation| replace:: ``PySys_SetArgvEx`` documentation
+    .. _PySys_SetArgvEx documentation: https://docs.python.org/3/c-api/init.html#c.PySys_SetArgvEx
+ \endrst */
+inline void initialize_interpreter(bool init_signal_handlers = true,
+                                   int argc = 0,
+                                   const char *const *argv = nullptr,
+                                   bool add_program_dir_to_path = true) {
+#if PY_VERSION_HEX < PYBIND11_PYCONFIG_SUPPORT_PY_VERSION_HEX
+    detail::initialize_interpreter_pre_pyconfig(
+        init_signal_handlers, argc, argv, add_program_dir_to_path);
+#else
+    PyConfig config;
+    PyConfig_InitPythonConfig(&config);
+    // See PR #4473 for background
+    config.parse_argv = 0;
+
+    config.install_signal_handlers = init_signal_handlers ? 1 : 0;
+    initialize_interpreter(&config, argc, argv, add_program_dir_to_path);
+#endif
+}
+
+/** \rst
+    Shut down the Python interpreter. No pybind11 or CPython API functions can be called
+    after this. In addition, pybind11 objects must not outlive the interpreter:
+
+    .. code-block:: cpp
+
+        { // BAD
+            py::initialize_interpreter();
+            auto hello = py::str("Hello, World!");
+            py::finalize_interpreter();
+        } // <-- BOOM, hello's destructor is called after interpreter shutdown
+
+        { // GOOD
+            py::initialize_interpreter();
+            { // scoped
+                auto hello = py::str("Hello, World!");
+            } // <-- OK, hello is cleaned up properly
+            py::finalize_interpreter();
+        }
+
+        { // BETTER
+            py::scoped_interpreter guard{};
+            auto hello = py::str("Hello, World!");
+        }
+
+    .. warning::
+
+        The interpreter can be restarted by calling `initialize_interpreter` again.
+        Modules created using pybind11 can be safely re-initialized. However, Python
+        itself cannot completely unload binary extension modules and there are several
+        caveats with regard to interpreter restarting. All the details can be found
+        in the CPython documentation. In short, not all interpreter memory may be
+        freed, either due to reference cycles or user-created global data.
+
+ \endrst */
+inline void finalize_interpreter() {
+    // Get the internals pointer (without creating it if it doesn't exist).  It's possible for the
+    // internals to be created during Py_Finalize() (e.g. if a py::capsule calls `get_internals()`
+    // during destruction), so we get the pointer-pointer here and check it after Py_Finalize().
+    detail::internals **internals_ptr_ptr = detail::get_internals_pp();
+    // It could also be stashed in state_dict, so look there too:
+    if (object internals_obj
+        = get_internals_obj_from_state_dict(detail::get_python_state_dict())) {
+        internals_ptr_ptr = detail::get_internals_pp_from_capsule(internals_obj);
+    }
+    // Local internals contains data managed by the current interpreter, so we must clear them to
+    // avoid undefined behaviors when initializing another interpreter
+    detail::get_local_internals().registered_types_cpp.clear();
+    detail::get_local_internals().registered_exception_translators.clear();
+
+    Py_Finalize();
+
+    if (internals_ptr_ptr) {
+        delete *internals_ptr_ptr;
+        *internals_ptr_ptr = nullptr;
+    }
+}
+
+/** \rst
+    Scope guard version of `initialize_interpreter` and `finalize_interpreter`.
+    This a move-only guard and only a single instance can exist.
+
+    See `initialize_interpreter` for a discussion of its constructor arguments.
+
+    .. code-block:: cpp
+
+        #include <pybind11/embed.h>
+
+        int main() {
+            py::scoped_interpreter guard{};
+            py::print(Hello, World!);
+        } // <-- interpreter shutdown
+ \endrst */
+class scoped_interpreter {
+public:
+    explicit scoped_interpreter(bool init_signal_handlers = true,
+                                int argc = 0,
+                                const char *const *argv = nullptr,
+                                bool add_program_dir_to_path = true) {
+        initialize_interpreter(init_signal_handlers, argc, argv, add_program_dir_to_path);
+    }
+
+#if PY_VERSION_HEX >= PYBIND11_PYCONFIG_SUPPORT_PY_VERSION_HEX
+    explicit scoped_interpreter(PyConfig *config,
+                                int argc = 0,
+                                const char *const *argv = nullptr,
+                                bool add_program_dir_to_path = true) {
+        initialize_interpreter(config, argc, argv, add_program_dir_to_path);
+    }
+#endif
+
+    scoped_interpreter(const scoped_interpreter &) = delete;
+    scoped_interpreter(scoped_interpreter &&other) noexcept { other.is_valid = false; }
+    scoped_interpreter &operator=(const scoped_interpreter &) = delete;
+    scoped_interpreter &operator=(scoped_interpreter &&) = delete;
+
+    ~scoped_interpreter() {
+        if (is_valid) {
+            finalize_interpreter();
+        }
+    }
+
+private:
+    bool is_valid = true;
+};
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/eval.h

@@ -0,0 +1,156 @@
+/*
+    pybind11/eval.h: Support for evaluating Python expressions and statements
+    from strings and files
+
+    Copyright (c) 2016 Klemens Morgenstern <klemens.morgenstern@ed-chemnitz.de> and
+                       Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+#include <utility>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+inline void ensure_builtins_in_globals(object &global) {
+#if defined(PYPY_VERSION) || PY_VERSION_HEX < 0x03080000
+    // Running exec and eval adds `builtins` module under `__builtins__` key to
+    // globals if not yet present.  Python 3.8 made PyRun_String behave
+    // similarly. Let's also do that for older versions, for consistency. This
+    // was missing from PyPy3.8 7.3.7.
+    if (!global.contains("__builtins__"))
+        global["__builtins__"] = module_::import(PYBIND11_BUILTINS_MODULE);
+#else
+    (void) global;
+#endif
+}
+
+PYBIND11_NAMESPACE_END(detail)
+
+enum eval_mode {
+    /// Evaluate a string containing an isolated expression
+    eval_expr,
+
+    /// Evaluate a string containing a single statement. Returns \c none
+    eval_single_statement,
+
+    /// Evaluate a string containing a sequence of statement. Returns \c none
+    eval_statements
+};
+
+template <eval_mode mode = eval_expr>
+object eval(const str &expr, object global = globals(), object local = object()) {
+    if (!local) {
+        local = global;
+    }
+
+    detail::ensure_builtins_in_globals(global);
+
+    /* PyRun_String does not accept a PyObject / encoding specifier,
+       this seems to be the only alternative */
+    std::string buffer = "# -*- coding: utf-8 -*-\n" + (std::string) expr;
+
+    int start = 0;
+    switch (mode) {
+        case eval_expr:
+            start = Py_eval_input;
+            break;
+        case eval_single_statement:
+            start = Py_single_input;
+            break;
+        case eval_statements:
+            start = Py_file_input;
+            break;
+        default:
+            pybind11_fail("invalid evaluation mode");
+    }
+
+    PyObject *result = PyRun_String(buffer.c_str(), start, global.ptr(), local.ptr());
+    if (!result) {
+        throw error_already_set();
+    }
+    return reinterpret_steal<object>(result);
+}
+
+template <eval_mode mode = eval_expr, size_t N>
+object eval(const char (&s)[N], object global = globals(), object local = object()) {
+    /* Support raw string literals by removing common leading whitespace */
+    auto expr = (s[0] == '\n') ? str(module_::import("textwrap").attr("dedent")(s)) : str(s);
+    return eval<mode>(expr, std::move(global), std::move(local));
+}
+
+inline void exec(const str &expr, object global = globals(), object local = object()) {
+    eval<eval_statements>(expr, std::move(global), std::move(local));
+}
+
+template <size_t N>
+void exec(const char (&s)[N], object global = globals(), object local = object()) {
+    eval<eval_statements>(s, std::move(global), std::move(local));
+}
+
+#if defined(PYPY_VERSION)
+template <eval_mode mode = eval_statements>
+object eval_file(str, object, object) {
+    pybind11_fail("eval_file not supported in PyPy3. Use eval");
+}
+template <eval_mode mode = eval_statements>
+object eval_file(str, object) {
+    pybind11_fail("eval_file not supported in PyPy3. Use eval");
+}
+template <eval_mode mode = eval_statements>
+object eval_file(str) {
+    pybind11_fail("eval_file not supported in PyPy3. Use eval");
+}
+#else
+template <eval_mode mode = eval_statements>
+object eval_file(str fname, object global = globals(), object local = object()) {
+    if (!local) {
+        local = global;
+    }
+
+    detail::ensure_builtins_in_globals(global);
+
+    int start = 0;
+    switch (mode) {
+        case eval_expr:
+            start = Py_eval_input;
+            break;
+        case eval_single_statement:
+            start = Py_single_input;
+            break;
+        case eval_statements:
+            start = Py_file_input;
+            break;
+        default:
+            pybind11_fail("invalid evaluation mode");
+    }
+
+    int closeFile = 1;
+    std::string fname_str = (std::string) fname;
+    FILE *f = _Py_fopen_obj(fname.ptr(), "r");
+    if (!f) {
+        PyErr_Clear();
+        pybind11_fail("File \"" + fname_str + "\" could not be opened!");
+    }
+
+    if (!global.contains("__file__")) {
+        global["__file__"] = std::move(fname);
+    }
+
+    PyObject *result
+        = PyRun_FileEx(f, fname_str.c_str(), start, global.ptr(), local.ptr(), closeFile);
+
+    if (!result) {
+        throw error_already_set();
+    }
+    return reinterpret_steal<object>(result);
+}
+#endif
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/functional.h

@@ -0,0 +1,137 @@
+/*
+    pybind11/functional.h: std::function<> support
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+#include <functional>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+template <typename Return, typename... Args>
+struct type_caster<std::function<Return(Args...)>> {
+    using type = std::function<Return(Args...)>;
+    using retval_type = conditional_t<std::is_same<Return, void>::value, void_type, Return>;
+    using function_type = Return (*)(Args...);
+
+public:
+    bool load(handle src, bool convert) {
+        if (src.is_none()) {
+            // Defer accepting None to other overloads (if we aren't in convert mode):
+            if (!convert) {
+                return false;
+            }
+            return true;
+        }
+
+        if (!isinstance<function>(src)) {
+            return false;
+        }
+
+        auto func = reinterpret_borrow<function>(src);
+
+        /*
+           When passing a C++ function as an argument to another C++
+           function via Python, every function call would normally involve
+           a full C++ -> Python -> C++ roundtrip, which can be prohibitive.
+           Here, we try to at least detect the case where the function is
+           stateless (i.e. function pointer or lambda function without
+           captured variables), in which case the roundtrip can be avoided.
+         */
+        if (auto cfunc = func.cpp_function()) {
+            auto *cfunc_self = PyCFunction_GET_SELF(cfunc.ptr());
+            if (cfunc_self == nullptr) {
+                PyErr_Clear();
+            } else if (isinstance<capsule>(cfunc_self)) {
+                auto c = reinterpret_borrow<capsule>(cfunc_self);
+
+                function_record *rec = nullptr;
+                // Check that we can safely reinterpret the capsule into a function_record
+                if (detail::is_function_record_capsule(c)) {
+                    rec = c.get_pointer<function_record>();
+                }
+
+                while (rec != nullptr) {
+                    if (rec->is_stateless
+                        && same_type(typeid(function_type),
+                                     *reinterpret_cast<const std::type_info *>(rec->data[1]))) {
+                        struct capture {
+                            function_type f;
+                        };
+                        value = ((capture *) &rec->data)->f;
+                        return true;
+                    }
+                    rec = rec->next;
+                }
+            }
+            // PYPY segfaults here when passing builtin function like sum.
+            // Raising an fail exception here works to prevent the segfault, but only on gcc.
+            // See PR #1413 for full details
+        }
+
+        // ensure GIL is held during functor destruction
+        struct func_handle {
+            function f;
+#if !(defined(_MSC_VER) && _MSC_VER == 1916 && defined(PYBIND11_CPP17))
+            // This triggers a syntax error under very special conditions (very weird indeed).
+            explicit
+#endif
+                func_handle(function &&f_) noexcept
+                : f(std::move(f_)) {
+            }
+            func_handle(const func_handle &f_) { operator=(f_); }
+            func_handle &operator=(const func_handle &f_) {
+                gil_scoped_acquire acq;
+                f = f_.f;
+                return *this;
+            }
+            ~func_handle() {
+                gil_scoped_acquire acq;
+                function kill_f(std::move(f));
+            }
+        };
+
+        // to emulate 'move initialization capture' in C++11
+        struct func_wrapper {
+            func_handle hfunc;
+            explicit func_wrapper(func_handle &&hf) noexcept : hfunc(std::move(hf)) {}
+            Return operator()(Args... args) const {
+                gil_scoped_acquire acq;
+                // casts the returned object as a rvalue to the return type
+                return hfunc.f(std::forward<Args>(args)...).template cast<Return>();
+            }
+        };
+
+        value = func_wrapper(func_handle(std::move(func)));
+        return true;
+    }
+
+    template <typename Func>
+    static handle cast(Func &&f_, return_value_policy policy, handle /* parent */) {
+        if (!f_) {
+            return none().release();
+        }
+
+        auto result = f_.template target<function_type>();
+        if (result) {
+            return cpp_function(*result, policy).release();
+        }
+        return cpp_function(std::forward<Func>(f_), policy).release();
+    }
+
+    PYBIND11_TYPE_CASTER(type,
+                         const_name("Callable[[") + concat(make_caster<Args>::name...)
+                             + const_name("], ") + make_caster<retval_type>::name
+                             + const_name("]"));
+};
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/gil.h

@@ -0,0 +1,239 @@
+/*
+    pybind11/gil.h: RAII helpers for managing the GIL
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "detail/common.h"
+
+#if defined(WITH_THREAD) && !defined(PYBIND11_SIMPLE_GIL_MANAGEMENT)
+#    include "detail/internals.h"
+#endif
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+// forward declarations
+PyThreadState *get_thread_state_unchecked();
+
+PYBIND11_NAMESPACE_END(detail)
+
+#if defined(WITH_THREAD)
+
+#    if !defined(PYBIND11_SIMPLE_GIL_MANAGEMENT)
+
+/* The functions below essentially reproduce the PyGILState_* API using a RAII
+ * pattern, but there are a few important differences:
+ *
+ * 1. When acquiring the GIL from an non-main thread during the finalization
+ *    phase, the GILState API blindly terminates the calling thread, which
+ *    is often not what is wanted. This API does not do this.
+ *
+ * 2. The gil_scoped_release function can optionally cut the relationship
+ *    of a PyThreadState and its associated thread, which allows moving it to
+ *    another thread (this is a fairly rare/advanced use case).
+ *
+ * 3. The reference count of an acquired thread state can be controlled. This
+ *    can be handy to prevent cases where callbacks issued from an external
+ *    thread would otherwise constantly construct and destroy thread state data
+ *    structures.
+ *
+ * See the Python bindings of NanoGUI (http://github.com/wjakob/nanogui) for an
+ * example which uses features 2 and 3 to migrate the Python thread of
+ * execution to another thread (to run the event loop on the original thread,
+ * in this case).
+ */
+
+class gil_scoped_acquire {
+public:
+    PYBIND11_NOINLINE gil_scoped_acquire() {
+        auto &internals = detail::get_internals();
+        tstate = (PyThreadState *) PYBIND11_TLS_GET_VALUE(internals.tstate);
+
+        if (!tstate) {
+            /* Check if the GIL was acquired using the PyGILState_* API instead (e.g. if
+               calling from a Python thread). Since we use a different key, this ensures
+               we don't create a new thread state and deadlock in PyEval_AcquireThread
+               below. Note we don't save this state with internals.tstate, since we don't
+               create it we would fail to clear it (its reference count should be > 0). */
+            tstate = PyGILState_GetThisThreadState();
+        }
+
+        if (!tstate) {
+            tstate = PyThreadState_New(internals.istate);
+#        if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
+            if (!tstate) {
+                pybind11_fail("scoped_acquire: could not create thread state!");
+            }
+#        endif
+            tstate->gilstate_counter = 0;
+            PYBIND11_TLS_REPLACE_VALUE(internals.tstate, tstate);
+        } else {
+            release = detail::get_thread_state_unchecked() != tstate;
+        }
+
+        if (release) {
+            PyEval_AcquireThread(tstate);
+        }
+
+        inc_ref();
+    }
+
+    gil_scoped_acquire(const gil_scoped_acquire &) = delete;
+    gil_scoped_acquire &operator=(const gil_scoped_acquire &) = delete;
+
+    void inc_ref() { ++tstate->gilstate_counter; }
+
+    PYBIND11_NOINLINE void dec_ref() {
+        --tstate->gilstate_counter;
+#        if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
+        if (detail::get_thread_state_unchecked() != tstate) {
+            pybind11_fail("scoped_acquire::dec_ref(): thread state must be current!");
+        }
+        if (tstate->gilstate_counter < 0) {
+            pybind11_fail("scoped_acquire::dec_ref(): reference count underflow!");
+        }
+#        endif
+        if (tstate->gilstate_counter == 0) {
+#        if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
+            if (!release) {
+                pybind11_fail("scoped_acquire::dec_ref(): internal error!");
+            }
+#        endif
+            PyThreadState_Clear(tstate);
+            if (active) {
+                PyThreadState_DeleteCurrent();
+            }
+            PYBIND11_TLS_DELETE_VALUE(detail::get_internals().tstate);
+            release = false;
+        }
+    }
+
+    /// This method will disable the PyThreadState_DeleteCurrent call and the
+    /// GIL won't be acquired. This method should be used if the interpreter
+    /// could be shutting down when this is called, as thread deletion is not
+    /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and
+    /// protect subsequent code.
+    PYBIND11_NOINLINE void disarm() { active = false; }
+
+    PYBIND11_NOINLINE ~gil_scoped_acquire() {
+        dec_ref();
+        if (release) {
+            PyEval_SaveThread();
+        }
+    }
+
+private:
+    PyThreadState *tstate = nullptr;
+    bool release = true;
+    bool active = true;
+};
+
+class gil_scoped_release {
+public:
+    explicit gil_scoped_release(bool disassoc = false) : disassoc(disassoc) {
+        // `get_internals()` must be called here unconditionally in order to initialize
+        // `internals.tstate` for subsequent `gil_scoped_acquire` calls. Otherwise, an
+        // initialization race could occur as multiple threads try `gil_scoped_acquire`.
+        auto &internals = detail::get_internals();
+        // NOLINTNEXTLINE(cppcoreguidelines-prefer-member-initializer)
+        tstate = PyEval_SaveThread();
+        if (disassoc) {
+            // Python >= 3.7 can remove this, it's an int before 3.7
+            // NOLINTNEXTLINE(readability-qualified-auto)
+            auto key = internals.tstate;
+            PYBIND11_TLS_DELETE_VALUE(key);
+        }
+    }
+
+    gil_scoped_release(const gil_scoped_release &) = delete;
+    gil_scoped_release &operator=(const gil_scoped_release &) = delete;
+
+    /// This method will disable the PyThreadState_DeleteCurrent call and the
+    /// GIL won't be acquired. This method should be used if the interpreter
+    /// could be shutting down when this is called, as thread deletion is not
+    /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and
+    /// protect subsequent code.
+    PYBIND11_NOINLINE void disarm() { active = false; }
+
+    ~gil_scoped_release() {
+        if (!tstate) {
+            return;
+        }
+        // `PyEval_RestoreThread()` should not be called if runtime is finalizing
+        if (active) {
+            PyEval_RestoreThread(tstate);
+        }
+        if (disassoc) {
+            // Python >= 3.7 can remove this, it's an int before 3.7
+            // NOLINTNEXTLINE(readability-qualified-auto)
+            auto key = detail::get_internals().tstate;
+            PYBIND11_TLS_REPLACE_VALUE(key, tstate);
+        }
+    }
+
+private:
+    PyThreadState *tstate;
+    bool disassoc;
+    bool active = true;
+};
+
+#    else // PYBIND11_SIMPLE_GIL_MANAGEMENT
+
+class gil_scoped_acquire {
+    PyGILState_STATE state;
+
+public:
+    gil_scoped_acquire() : state{PyGILState_Ensure()} {}
+    gil_scoped_acquire(const gil_scoped_acquire &) = delete;
+    gil_scoped_acquire &operator=(const gil_scoped_acquire &) = delete;
+    ~gil_scoped_acquire() { PyGILState_Release(state); }
+    void disarm() {}
+};
+
+class gil_scoped_release {
+    PyThreadState *state;
+
+public:
+    gil_scoped_release() : state{PyEval_SaveThread()} {}
+    gil_scoped_release(const gil_scoped_release &) = delete;
+    gil_scoped_release &operator=(const gil_scoped_release &) = delete;
+    ~gil_scoped_release() { PyEval_RestoreThread(state); }
+    void disarm() {}
+};
+
+#    endif // PYBIND11_SIMPLE_GIL_MANAGEMENT
+
+#else // WITH_THREAD
+
+class gil_scoped_acquire {
+public:
+    gil_scoped_acquire() {
+        // Trick to suppress `unused variable` error messages (at call sites).
+        (void) (this != (this + 1));
+    }
+    gil_scoped_acquire(const gil_scoped_acquire &) = delete;
+    gil_scoped_acquire &operator=(const gil_scoped_acquire &) = delete;
+    void disarm() {}
+};
+
+class gil_scoped_release {
+public:
+    gil_scoped_release() {
+        // Trick to suppress `unused variable` error messages (at call sites).
+        (void) (this != (this + 1));
+    }
+    gil_scoped_release(const gil_scoped_release &) = delete;
+    gil_scoped_release &operator=(const gil_scoped_release &) = delete;
+    void disarm() {}
+};
+
+#endif // WITH_THREAD
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/iostream.h

@@ -0,0 +1,265 @@
+/*
+    pybind11/iostream.h -- Tools to assist with redirecting cout and cerr to Python
+
+    Copyright (c) 2017 Henry F. Schreiner
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+
+    WARNING: The implementation in this file is NOT thread safe. Multiple
+    threads writing to a redirected ostream concurrently cause data races
+    and potentially buffer overflows. Therefore it is currently a requirement
+    that all (possibly) concurrent redirected ostream writes are protected by
+    a mutex.
+    #HelpAppreciated: Work on iostream.h thread safety.
+    For more background see the discussions under
+    https://github.com/pybind/pybind11/pull/2982 and
+    https://github.com/pybind/pybind11/pull/2995.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+#include <algorithm>
+#include <cstring>
+#include <iostream>
+#include <iterator>
+#include <memory>
+#include <ostream>
+#include <streambuf>
+#include <string>
+#include <utility>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+// Buffer that writes to Python instead of C++
+class pythonbuf : public std::streambuf {
+private:
+    using traits_type = std::streambuf::traits_type;
+
+    const size_t buf_size;
+    std::unique_ptr<char[]> d_buffer;
+    object pywrite;
+    object pyflush;
+
+    int overflow(int c) override {
+        if (!traits_type::eq_int_type(c, traits_type::eof())) {
+            *pptr() = traits_type::to_char_type(c);
+            pbump(1);
+        }
+        return sync() == 0 ? traits_type::not_eof(c) : traits_type::eof();
+    }
+
+    // Computes how many bytes at the end of the buffer are part of an
+    // incomplete sequence of UTF-8 bytes.
+    // Precondition: pbase() < pptr()
+    size_t utf8_remainder() const {
+        const auto rbase = std::reverse_iterator<char *>(pbase());
+        const auto rpptr = std::reverse_iterator<char *>(pptr());
+        auto is_ascii = [](char c) { return (static_cast<unsigned char>(c) & 0x80) == 0x00; };
+        auto is_leading = [](char c) { return (static_cast<unsigned char>(c) & 0xC0) == 0xC0; };
+        auto is_leading_2b = [](char c) { return static_cast<unsigned char>(c) <= 0xDF; };
+        auto is_leading_3b = [](char c) { return static_cast<unsigned char>(c) <= 0xEF; };
+        // If the last character is ASCII, there are no incomplete code points
+        if (is_ascii(*rpptr)) {
+            return 0;
+        }
+        // Otherwise, work back from the end of the buffer and find the first
+        // UTF-8 leading byte
+        const auto rpend = rbase - rpptr >= 3 ? rpptr + 3 : rbase;
+        const auto leading = std::find_if(rpptr, rpend, is_leading);
+        if (leading == rbase) {
+            return 0;
+        }
+        const auto dist = static_cast<size_t>(leading - rpptr);
+        size_t remainder = 0;
+
+        if (dist == 0) {
+            remainder = 1; // 1-byte code point is impossible
+        } else if (dist == 1) {
+            remainder = is_leading_2b(*leading) ? 0 : dist + 1;
+        } else if (dist == 2) {
+            remainder = is_leading_3b(*leading) ? 0 : dist + 1;
+        }
+        // else if (dist >= 3), at least 4 bytes before encountering an UTF-8
+        // leading byte, either no remainder or invalid UTF-8.
+        // Invalid UTF-8 will cause an exception later when converting
+        // to a Python string, so that's not handled here.
+        return remainder;
+    }
+
+    // This function must be non-virtual to be called in a destructor.
+    int _sync() {
+        if (pbase() != pptr()) { // If buffer is not empty
+            gil_scoped_acquire tmp;
+            // This subtraction cannot be negative, so dropping the sign.
+            auto size = static_cast<size_t>(pptr() - pbase());
+            size_t remainder = utf8_remainder();
+
+            if (size > remainder) {
+                str line(pbase(), size - remainder);
+                pywrite(std::move(line));
+                pyflush();
+            }
+
+            // Copy the remainder at the end of the buffer to the beginning:
+            if (remainder > 0) {
+                std::memmove(pbase(), pptr() - remainder, remainder);
+            }
+            setp(pbase(), epptr());
+            pbump(static_cast<int>(remainder));
+        }
+        return 0;
+    }
+
+    int sync() override { return _sync(); }
+
+public:
+    explicit pythonbuf(const object &pyostream, size_t buffer_size = 1024)
+        : buf_size(buffer_size), d_buffer(new char[buf_size]), pywrite(pyostream.attr("write")),
+          pyflush(pyostream.attr("flush")) {
+        setp(d_buffer.get(), d_buffer.get() + buf_size - 1);
+    }
+
+    pythonbuf(pythonbuf &&) = default;
+
+    /// Sync before destroy
+    ~pythonbuf() override { _sync(); }
+};
+
+PYBIND11_NAMESPACE_END(detail)
+
+/** \rst
+    This a move-only guard that redirects output.
+
+    .. code-block:: cpp
+
+        #include <pybind11/iostream.h>
+
+        ...
+
+        {
+            py::scoped_ostream_redirect output;
+            std::cout << "Hello, World!"; // Python stdout
+        } // <-- return std::cout to normal
+
+    You can explicitly pass the c++ stream and the python object,
+    for example to guard stderr instead.
+
+    .. code-block:: cpp
+
+        {
+            py::scoped_ostream_redirect output{
+                std::cerr, py::module::import("sys").attr("stderr")};
+            std::cout << "Hello, World!";
+        }
+ \endrst */
+class scoped_ostream_redirect {
+protected:
+    std::streambuf *old;
+    std::ostream &costream;
+    detail::pythonbuf buffer;
+
+public:
+    explicit scoped_ostream_redirect(std::ostream &costream = std::cout,
+                                     const object &pyostream
+                                     = module_::import("sys").attr("stdout"))
+        : costream(costream), buffer(pyostream) {
+        old = costream.rdbuf(&buffer);
+    }
+
+    ~scoped_ostream_redirect() { costream.rdbuf(old); }
+
+    scoped_ostream_redirect(const scoped_ostream_redirect &) = delete;
+    scoped_ostream_redirect(scoped_ostream_redirect &&other) = default;
+    scoped_ostream_redirect &operator=(const scoped_ostream_redirect &) = delete;
+    scoped_ostream_redirect &operator=(scoped_ostream_redirect &&) = delete;
+};
+
+/** \rst
+    Like `scoped_ostream_redirect`, but redirects cerr by default. This class
+    is provided primary to make ``py::call_guard`` easier to make.
+
+    .. code-block:: cpp
+
+     m.def("noisy_func", &noisy_func,
+           py::call_guard<scoped_ostream_redirect,
+                          scoped_estream_redirect>());
+
+\endrst */
+class scoped_estream_redirect : public scoped_ostream_redirect {
+public:
+    explicit scoped_estream_redirect(std::ostream &costream = std::cerr,
+                                     const object &pyostream
+                                     = module_::import("sys").attr("stderr"))
+        : scoped_ostream_redirect(costream, pyostream) {}
+};
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+// Class to redirect output as a context manager. C++ backend.
+class OstreamRedirect {
+    bool do_stdout_;
+    bool do_stderr_;
+    std::unique_ptr<scoped_ostream_redirect> redirect_stdout;
+    std::unique_ptr<scoped_estream_redirect> redirect_stderr;
+
+public:
+    explicit OstreamRedirect(bool do_stdout = true, bool do_stderr = true)
+        : do_stdout_(do_stdout), do_stderr_(do_stderr) {}
+
+    void enter() {
+        if (do_stdout_) {
+            redirect_stdout.reset(new scoped_ostream_redirect());
+        }
+        if (do_stderr_) {
+            redirect_stderr.reset(new scoped_estream_redirect());
+        }
+    }
+
+    void exit() {
+        redirect_stdout.reset();
+        redirect_stderr.reset();
+    }
+};
+
+PYBIND11_NAMESPACE_END(detail)
+
+/** \rst
+    This is a helper function to add a C++ redirect context manager to Python
+    instead of using a C++ guard. To use it, add the following to your binding code:
+
+    .. code-block:: cpp
+
+        #include <pybind11/iostream.h>
+
+        ...
+
+        py::add_ostream_redirect(m, "ostream_redirect");
+
+    You now have a Python context manager that redirects your output:
+
+    .. code-block:: python
+
+        with m.ostream_redirect():
+            m.print_to_cout_function()
+
+    This manager can optionally be told which streams to operate on:
+
+    .. code-block:: python
+
+        with m.ostream_redirect(stdout=true, stderr=true):
+            m.noisy_function_with_error_printing()
+
+ \endrst */
+inline class_<detail::OstreamRedirect>
+add_ostream_redirect(module_ m, const std::string &name = "ostream_redirect") {
+    return class_<detail::OstreamRedirect>(std::move(m), name.c_str(), module_local())
+        .def(init<bool, bool>(), arg("stdout") = true, arg("stderr") = true)
+        .def("__enter__", &detail::OstreamRedirect::enter)
+        .def("__exit__", [](detail::OstreamRedirect &self_, const args &) { self_.exit(); });
+}
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/operators.h

@@ -0,0 +1,202 @@
+/*
+    pybind11/operator.h: Metatemplates for operator overloading
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/// Enumeration with all supported operator types
+enum op_id : int {
+    op_add,
+    op_sub,
+    op_mul,
+    op_div,
+    op_mod,
+    op_divmod,
+    op_pow,
+    op_lshift,
+    op_rshift,
+    op_and,
+    op_xor,
+    op_or,
+    op_neg,
+    op_pos,
+    op_abs,
+    op_invert,
+    op_int,
+    op_long,
+    op_float,
+    op_str,
+    op_cmp,
+    op_gt,
+    op_ge,
+    op_lt,
+    op_le,
+    op_eq,
+    op_ne,
+    op_iadd,
+    op_isub,
+    op_imul,
+    op_idiv,
+    op_imod,
+    op_ilshift,
+    op_irshift,
+    op_iand,
+    op_ixor,
+    op_ior,
+    op_complex,
+    op_bool,
+    op_nonzero,
+    op_repr,
+    op_truediv,
+    op_itruediv,
+    op_hash
+};
+
+enum op_type : int {
+    op_l, /* base type on left */
+    op_r, /* base type on right */
+    op_u  /* unary operator */
+};
+
+struct self_t {};
+static const self_t self = self_t();
+
+/// Type for an unused type slot
+struct undefined_t {};
+
+/// Don't warn about an unused variable
+inline self_t __self() { return self; }
+
+/// base template of operator implementations
+template <op_id, op_type, typename B, typename L, typename R>
+struct op_impl {};
+
+/// Operator implementation generator
+template <op_id id, op_type ot, typename L, typename R>
+struct op_ {
+    static constexpr bool op_enable_if_hook = true;
+    template <typename Class, typename... Extra>
+    void execute(Class &cl, const Extra &...extra) const {
+        using Base = typename Class::type;
+        using L_type = conditional_t<std::is_same<L, self_t>::value, Base, L>;
+        using R_type = conditional_t<std::is_same<R, self_t>::value, Base, R>;
+        using op = op_impl<id, ot, Base, L_type, R_type>;
+        cl.def(op::name(), &op::execute, is_operator(), extra...);
+    }
+    template <typename Class, typename... Extra>
+    void execute_cast(Class &cl, const Extra &...extra) const {
+        using Base = typename Class::type;
+        using L_type = conditional_t<std::is_same<L, self_t>::value, Base, L>;
+        using R_type = conditional_t<std::is_same<R, self_t>::value, Base, R>;
+        using op = op_impl<id, ot, Base, L_type, R_type>;
+        cl.def(op::name(), &op::execute_cast, is_operator(), extra...);
+    }
+};
+
+#define PYBIND11_BINARY_OPERATOR(id, rid, op, expr)                                               \
+    template <typename B, typename L, typename R>                                                 \
+    struct op_impl<op_##id, op_l, B, L, R> {                                                      \
+        static char const *name() { return "__" #id "__"; }                                       \
+        static auto execute(const L &l, const R &r) -> decltype(expr) { return (expr); }          \
+        static B execute_cast(const L &l, const R &r) { return B(expr); }                         \
+    };                                                                                            \
+    template <typename B, typename L, typename R>                                                 \
+    struct op_impl<op_##id, op_r, B, L, R> {                                                      \
+        static char const *name() { return "__" #rid "__"; }                                      \
+        static auto execute(const R &r, const L &l) -> decltype(expr) { return (expr); }          \
+        static B execute_cast(const R &r, const L &l) { return B(expr); }                         \
+    };                                                                                            \
+    inline op_<op_##id, op_l, self_t, self_t> op(const self_t &, const self_t &) {                \
+        return op_<op_##id, op_l, self_t, self_t>();                                              \
+    }                                                                                             \
+    template <typename T>                                                                         \
+    op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {                                 \
+        return op_<op_##id, op_l, self_t, T>();                                                   \
+    }                                                                                             \
+    template <typename T>                                                                         \
+    op_<op_##id, op_r, T, self_t> op(const T &, const self_t &) {                                 \
+        return op_<op_##id, op_r, T, self_t>();                                                   \
+    }
+
+#define PYBIND11_INPLACE_OPERATOR(id, op, expr)                                                   \
+    template <typename B, typename L, typename R>                                                 \
+    struct op_impl<op_##id, op_l, B, L, R> {                                                      \
+        static char const *name() { return "__" #id "__"; }                                       \
+        static auto execute(L &l, const R &r) -> decltype(expr) { return expr; }                  \
+        static B execute_cast(L &l, const R &r) { return B(expr); }                               \
+    };                                                                                            \
+    template <typename T>                                                                         \
+    op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {                                 \
+        return op_<op_##id, op_l, self_t, T>();                                                   \
+    }
+
+#define PYBIND11_UNARY_OPERATOR(id, op, expr)                                                     \
+    template <typename B, typename L>                                                             \
+    struct op_impl<op_##id, op_u, B, L, undefined_t> {                                            \
+        static char const *name() { return "__" #id "__"; }                                       \
+        static auto execute(const L &l) -> decltype(expr) { return expr; }                        \
+        static B execute_cast(const L &l) { return B(expr); }                                     \
+    };                                                                                            \
+    inline op_<op_##id, op_u, self_t, undefined_t> op(const self_t &) {                           \
+        return op_<op_##id, op_u, self_t, undefined_t>();                                         \
+    }
+
+PYBIND11_BINARY_OPERATOR(sub, rsub, operator-, l - r)
+PYBIND11_BINARY_OPERATOR(add, radd, operator+, l + r)
+PYBIND11_BINARY_OPERATOR(mul, rmul, operator*, l *r)
+PYBIND11_BINARY_OPERATOR(truediv, rtruediv, operator/, l / r)
+PYBIND11_BINARY_OPERATOR(mod, rmod, operator%, l % r)
+PYBIND11_BINARY_OPERATOR(lshift, rlshift, operator<<, l << r)
+PYBIND11_BINARY_OPERATOR(rshift, rrshift, operator>>, l >> r)
+PYBIND11_BINARY_OPERATOR(and, rand, operator&, l &r)
+PYBIND11_BINARY_OPERATOR(xor, rxor, operator^, l ^ r)
+PYBIND11_BINARY_OPERATOR(eq, eq, operator==, l == r)
+PYBIND11_BINARY_OPERATOR(ne, ne, operator!=, l != r)
+PYBIND11_BINARY_OPERATOR(or, ror, operator|, l | r)
+PYBIND11_BINARY_OPERATOR(gt, lt, operator>, l > r)
+PYBIND11_BINARY_OPERATOR(ge, le, operator>=, l >= r)
+PYBIND11_BINARY_OPERATOR(lt, gt, operator<, l < r)
+PYBIND11_BINARY_OPERATOR(le, ge, operator<=, l <= r)
+// PYBIND11_BINARY_OPERATOR(pow,       rpow,         pow,          std::pow(l,  r))
+PYBIND11_INPLACE_OPERATOR(iadd, operator+=, l += r)
+PYBIND11_INPLACE_OPERATOR(isub, operator-=, l -= r)
+PYBIND11_INPLACE_OPERATOR(imul, operator*=, l *= r)
+PYBIND11_INPLACE_OPERATOR(itruediv, operator/=, l /= r)
+PYBIND11_INPLACE_OPERATOR(imod, operator%=, l %= r)
+PYBIND11_INPLACE_OPERATOR(ilshift, operator<<=, l <<= r)
+PYBIND11_INPLACE_OPERATOR(irshift, operator>>=, l >>= r)
+PYBIND11_INPLACE_OPERATOR(iand, operator&=, l &= r)
+PYBIND11_INPLACE_OPERATOR(ixor, operator^=, l ^= r)
+PYBIND11_INPLACE_OPERATOR(ior, operator|=, l |= r)
+PYBIND11_UNARY_OPERATOR(neg, operator-, -l)
+PYBIND11_UNARY_OPERATOR(pos, operator+, +l)
+// WARNING: This usage of `abs` should only be done for existing STL overloads.
+// Adding overloads directly in to the `std::` namespace is advised against:
+// https://en.cppreference.com/w/cpp/language/extending_std
+PYBIND11_UNARY_OPERATOR(abs, abs, std::abs(l))
+PYBIND11_UNARY_OPERATOR(hash, hash, std::hash<L>()(l))
+PYBIND11_UNARY_OPERATOR(invert, operator~, (~l))
+PYBIND11_UNARY_OPERATOR(bool, operator!, !!l)
+PYBIND11_UNARY_OPERATOR(int, int_, (int) l)
+PYBIND11_UNARY_OPERATOR(float, float_, (double) l)
+
+#undef PYBIND11_BINARY_OPERATOR
+#undef PYBIND11_INPLACE_OPERATOR
+#undef PYBIND11_UNARY_OPERATOR
+PYBIND11_NAMESPACE_END(detail)
+
+using detail::self;
+// Add named operators so that they are accessible via `py::`.
+using detail::hash;
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/options.h

@@ -0,0 +1,92 @@
+/*
+    pybind11/options.h: global settings that are configurable at runtime.
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "detail/common.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+class options {
+public:
+    // Default RAII constructor, which leaves settings as they currently are.
+    options() : previous_state(global_state()) {}
+
+    // Class is non-copyable.
+    options(const options &) = delete;
+    options &operator=(const options &) = delete;
+
+    // Destructor, which restores settings that were in effect before.
+    ~options() { global_state() = previous_state; }
+
+    // Setter methods (affect the global state):
+
+    options &disable_user_defined_docstrings() & {
+        global_state().show_user_defined_docstrings = false;
+        return *this;
+    }
+
+    options &enable_user_defined_docstrings() & {
+        global_state().show_user_defined_docstrings = true;
+        return *this;
+    }
+
+    options &disable_function_signatures() & {
+        global_state().show_function_signatures = false;
+        return *this;
+    }
+
+    options &enable_function_signatures() & {
+        global_state().show_function_signatures = true;
+        return *this;
+    }
+
+    options &disable_enum_members_docstring() & {
+        global_state().show_enum_members_docstring = false;
+        return *this;
+    }
+
+    options &enable_enum_members_docstring() & {
+        global_state().show_enum_members_docstring = true;
+        return *this;
+    }
+
+    // Getter methods (return the global state):
+
+    static bool show_user_defined_docstrings() {
+        return global_state().show_user_defined_docstrings;
+    }
+
+    static bool show_function_signatures() { return global_state().show_function_signatures; }
+
+    static bool show_enum_members_docstring() {
+        return global_state().show_enum_members_docstring;
+    }
+
+    // This type is not meant to be allocated on the heap.
+    void *operator new(size_t) = delete;
+
+private:
+    struct state {
+        bool show_user_defined_docstrings = true; //< Include user-supplied texts in docstrings.
+        bool show_function_signatures = true;     //< Include auto-generated function signatures
+                                                  //  in docstrings.
+        bool show_enum_members_docstring = true;  //< Include auto-generated member list in enum
+                                                  //  docstrings.
+    };
+
+    static state &global_state() {
+        static state instance;
+        return instance;
+    }
+
+    state previous_state;
+};
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/stl.h

@@ -0,0 +1,447 @@
+/*
+    pybind11/stl.h: Transparent conversion for STL data types
+
+    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+#include "detail/common.h"
+
+#include <deque>
+#include <list>
+#include <map>
+#include <ostream>
+#include <set>
+#include <unordered_map>
+#include <unordered_set>
+#include <valarray>
+
+// See `detail/common.h` for implementation of these guards.
+#if defined(PYBIND11_HAS_OPTIONAL)
+#    include <optional>
+#elif defined(PYBIND11_HAS_EXP_OPTIONAL)
+#    include <experimental/optional>
+#endif
+
+#if defined(PYBIND11_HAS_VARIANT)
+#    include <variant>
+#endif
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/// Extracts an const lvalue reference or rvalue reference for U based on the type of T (e.g. for
+/// forwarding a container element).  Typically used indirect via forwarded_type(), below.
+template <typename T, typename U>
+using forwarded_type = conditional_t<std::is_lvalue_reference<T>::value,
+                                     remove_reference_t<U> &,
+                                     remove_reference_t<U> &&>;
+
+/// Forwards a value U as rvalue or lvalue according to whether T is rvalue or lvalue; typically
+/// used for forwarding a container's elements.
+template <typename T, typename U>
+constexpr forwarded_type<T, U> forward_like(U &&u) {
+    return std::forward<detail::forwarded_type<T, U>>(std::forward<U>(u));
+}
+
+// Checks if a container has a STL style reserve method.
+// This will only return true for a `reserve()` with a `void` return.
+template <typename C>
+using has_reserve_method = std::is_same<decltype(std::declval<C>().reserve(0)), void>;
+
+template <typename Type, typename Key>
+struct set_caster {
+    using type = Type;
+    using key_conv = make_caster<Key>;
+
+private:
+    template <typename T = Type, enable_if_t<has_reserve_method<T>::value, int> = 0>
+    void reserve_maybe(const anyset &s, Type *) {
+        value.reserve(s.size());
+    }
+    void reserve_maybe(const anyset &, void *) {}
+
+public:
+    bool load(handle src, bool convert) {
+        if (!isinstance<anyset>(src)) {
+            return false;
+        }
+        auto s = reinterpret_borrow<anyset>(src);
+        value.clear();
+        reserve_maybe(s, &value);
+        for (auto entry : s) {
+            key_conv conv;
+            if (!conv.load(entry, convert)) {
+                return false;
+            }
+            value.insert(cast_op<Key &&>(std::move(conv)));
+        }
+        return true;
+    }
+
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        if (!std::is_lvalue_reference<T>::value) {
+            policy = return_value_policy_override<Key>::policy(policy);
+        }
+        pybind11::set s;
+        for (auto &&value : src) {
+            auto value_ = reinterpret_steal<object>(
+                key_conv::cast(detail::forward_like<T>(value), policy, parent));
+            if (!value_ || !s.add(std::move(value_))) {
+                return handle();
+            }
+        }
+        return s.release();
+    }
+
+    PYBIND11_TYPE_CASTER(type, const_name("Set[") + key_conv::name + const_name("]"));
+};
+
+template <typename Type, typename Key, typename Value>
+struct map_caster {
+    using key_conv = make_caster<Key>;
+    using value_conv = make_caster<Value>;
+
+private:
+    template <typename T = Type, enable_if_t<has_reserve_method<T>::value, int> = 0>
+    void reserve_maybe(const dict &d, Type *) {
+        value.reserve(d.size());
+    }
+    void reserve_maybe(const dict &, void *) {}
+
+public:
+    bool load(handle src, bool convert) {
+        if (!isinstance<dict>(src)) {
+            return false;
+        }
+        auto d = reinterpret_borrow<dict>(src);
+        value.clear();
+        reserve_maybe(d, &value);
+        for (auto it : d) {
+            key_conv kconv;
+            value_conv vconv;
+            if (!kconv.load(it.first.ptr(), convert) || !vconv.load(it.second.ptr(), convert)) {
+                return false;
+            }
+            value.emplace(cast_op<Key &&>(std::move(kconv)), cast_op<Value &&>(std::move(vconv)));
+        }
+        return true;
+    }
+
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        dict d;
+        return_value_policy policy_key = policy;
+        return_value_policy policy_value = policy;
+        if (!std::is_lvalue_reference<T>::value) {
+            policy_key = return_value_policy_override<Key>::policy(policy_key);
+            policy_value = return_value_policy_override<Value>::policy(policy_value);
+        }
+        for (auto &&kv : src) {
+            auto key = reinterpret_steal<object>(
+                key_conv::cast(detail::forward_like<T>(kv.first), policy_key, parent));
+            auto value = reinterpret_steal<object>(
+                value_conv::cast(detail::forward_like<T>(kv.second), policy_value, parent));
+            if (!key || !value) {
+                return handle();
+            }
+            d[std::move(key)] = std::move(value);
+        }
+        return d.release();
+    }
+
+    PYBIND11_TYPE_CASTER(Type,
+                         const_name("Dict[") + key_conv::name + const_name(", ") + value_conv::name
+                             + const_name("]"));
+};
+
+template <typename Type, typename Value>
+struct list_caster {
+    using value_conv = make_caster<Value>;
+
+    bool load(handle src, bool convert) {
+        if (!isinstance<sequence>(src) || isinstance<bytes>(src) || isinstance<str>(src)) {
+            return false;
+        }
+        auto s = reinterpret_borrow<sequence>(src);
+        value.clear();
+        reserve_maybe(s, &value);
+        for (auto it : s) {
+            value_conv conv;
+            if (!conv.load(it, convert)) {
+                return false;
+            }
+            value.push_back(cast_op<Value &&>(std::move(conv)));
+        }
+        return true;
+    }
+
+private:
+    template <typename T = Type, enable_if_t<has_reserve_method<T>::value, int> = 0>
+    void reserve_maybe(const sequence &s, Type *) {
+        value.reserve(s.size());
+    }
+    void reserve_maybe(const sequence &, void *) {}
+
+public:
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        if (!std::is_lvalue_reference<T>::value) {
+            policy = return_value_policy_override<Value>::policy(policy);
+        }
+        list l(src.size());
+        ssize_t index = 0;
+        for (auto &&value : src) {
+            auto value_ = reinterpret_steal<object>(
+                value_conv::cast(detail::forward_like<T>(value), policy, parent));
+            if (!value_) {
+                return handle();
+            }
+            PyList_SET_ITEM(l.ptr(), index++, value_.release().ptr()); // steals a reference
+        }
+        return l.release();
+    }
+
+    PYBIND11_TYPE_CASTER(Type, const_name("List[") + value_conv::name + const_name("]"));
+};
+
+template <typename Type, typename Alloc>
+struct type_caster<std::vector<Type, Alloc>> : list_caster<std::vector<Type, Alloc>, Type> {};
+
+template <typename Type, typename Alloc>
+struct type_caster<std::deque<Type, Alloc>> : list_caster<std::deque<Type, Alloc>, Type> {};
+
+template <typename Type, typename Alloc>
+struct type_caster<std::list<Type, Alloc>> : list_caster<std::list<Type, Alloc>, Type> {};
+
+template <typename ArrayType, typename Value, bool Resizable, size_t Size = 0>
+struct array_caster {
+    using value_conv = make_caster<Value>;
+
+private:
+    template <bool R = Resizable>
+    bool require_size(enable_if_t<R, size_t> size) {
+        if (value.size() != size) {
+            value.resize(size);
+        }
+        return true;
+    }
+    template <bool R = Resizable>
+    bool require_size(enable_if_t<!R, size_t> size) {
+        return size == Size;
+    }
+
+public:
+    bool load(handle src, bool convert) {
+        if (!isinstance<sequence>(src)) {
+            return false;
+        }
+        auto l = reinterpret_borrow<sequence>(src);
+        if (!require_size(l.size())) {
+            return false;
+        }
+        size_t ctr = 0;
+        for (auto it : l) {
+            value_conv conv;
+            if (!conv.load(it, convert)) {
+                return false;
+            }
+            value[ctr++] = cast_op<Value &&>(std::move(conv));
+        }
+        return true;
+    }
+
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        list l(src.size());
+        ssize_t index = 0;
+        for (auto &&value : src) {
+            auto value_ = reinterpret_steal<object>(
+                value_conv::cast(detail::forward_like<T>(value), policy, parent));
+            if (!value_) {
+                return handle();
+            }
+            PyList_SET_ITEM(l.ptr(), index++, value_.release().ptr()); // steals a reference
+        }
+        return l.release();
+    }
+
+    PYBIND11_TYPE_CASTER(ArrayType,
+                         const_name<Resizable>(const_name(""), const_name("Annotated["))
+                             + const_name("List[") + value_conv::name + const_name("]")
+                             + const_name<Resizable>(const_name(""),
+                                                     const_name(", FixedSize(")
+                                                         + const_name<Size>() + const_name(")]")));
+};
+
+template <typename Type, size_t Size>
+struct type_caster<std::array<Type, Size>>
+    : array_caster<std::array<Type, Size>, Type, false, Size> {};
+
+template <typename Type>
+struct type_caster<std::valarray<Type>> : array_caster<std::valarray<Type>, Type, true> {};
+
+template <typename Key, typename Compare, typename Alloc>
+struct type_caster<std::set<Key, Compare, Alloc>>
+    : set_caster<std::set<Key, Compare, Alloc>, Key> {};
+
+template <typename Key, typename Hash, typename Equal, typename Alloc>
+struct type_caster<std::unordered_set<Key, Hash, Equal, Alloc>>
+    : set_caster<std::unordered_set<Key, Hash, Equal, Alloc>, Key> {};
+
+template <typename Key, typename Value, typename Compare, typename Alloc>
+struct type_caster<std::map<Key, Value, Compare, Alloc>>
+    : map_caster<std::map<Key, Value, Compare, Alloc>, Key, Value> {};
+
+template <typename Key, typename Value, typename Hash, typename Equal, typename Alloc>
+struct type_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>>
+    : map_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>, Key, Value> {};
+
+// This type caster is intended to be used for std::optional and std::experimental::optional
+template <typename Type, typename Value = typename Type::value_type>
+struct optional_caster {
+    using value_conv = make_caster<Value>;
+
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        if (!src) {
+            return none().release();
+        }
+        if (!std::is_lvalue_reference<T>::value) {
+            policy = return_value_policy_override<Value>::policy(policy);
+        }
+        // NOLINTNEXTLINE(bugprone-unchecked-optional-access)
+        return value_conv::cast(*std::forward<T>(src), policy, parent);
+    }
+
+    bool load(handle src, bool convert) {
+        if (!src) {
+            return false;
+        }
+        if (src.is_none()) {
+            return true; // default-constructed value is already empty
+        }
+        value_conv inner_caster;
+        if (!inner_caster.load(src, convert)) {
+            return false;
+        }
+
+        value.emplace(cast_op<Value &&>(std::move(inner_caster)));
+        return true;
+    }
+
+    PYBIND11_TYPE_CASTER(Type, const_name("Optional[") + value_conv::name + const_name("]"));
+};
+
+#if defined(PYBIND11_HAS_OPTIONAL)
+template <typename T>
+struct type_caster<std::optional<T>> : public optional_caster<std::optional<T>> {};
+
+template <>
+struct type_caster<std::nullopt_t> : public void_caster<std::nullopt_t> {};
+#endif
+
+#if defined(PYBIND11_HAS_EXP_OPTIONAL)
+template <typename T>
+struct type_caster<std::experimental::optional<T>>
+    : public optional_caster<std::experimental::optional<T>> {};
+
+template <>
+struct type_caster<std::experimental::nullopt_t>
+    : public void_caster<std::experimental::nullopt_t> {};
+#endif
+
+/// Visit a variant and cast any found type to Python
+struct variant_caster_visitor {
+    return_value_policy policy;
+    handle parent;
+
+    using result_type = handle; // required by boost::variant in C++11
+
+    template <typename T>
+    result_type operator()(T &&src) const {
+        return make_caster<T>::cast(std::forward<T>(src), policy, parent);
+    }
+};
+
+/// Helper class which abstracts away variant's `visit` function. `std::variant` and similar
+/// `namespace::variant` types which provide a `namespace::visit()` function are handled here
+/// automatically using argument-dependent lookup. Users can provide specializations for other
+/// variant-like classes, e.g. `boost::variant` and `boost::apply_visitor`.
+template <template <typename...> class Variant>
+struct visit_helper {
+    template <typename... Args>
+    static auto call(Args &&...args) -> decltype(visit(std::forward<Args>(args)...)) {
+        return visit(std::forward<Args>(args)...);
+    }
+};
+
+/// Generic variant caster
+template <typename Variant>
+struct variant_caster;
+
+template <template <typename...> class V, typename... Ts>
+struct variant_caster<V<Ts...>> {
+    static_assert(sizeof...(Ts) > 0, "Variant must consist of at least one alternative.");
+
+    template <typename U, typename... Us>
+    bool load_alternative(handle src, bool convert, type_list<U, Us...>) {
+        auto caster = make_caster<U>();
+        if (caster.load(src, convert)) {
+            value = cast_op<U>(std::move(caster));
+            return true;
+        }
+        return load_alternative(src, convert, type_list<Us...>{});
+    }
+
+    bool load_alternative(handle, bool, type_list<>) { return false; }
+
+    bool load(handle src, bool convert) {
+        // Do a first pass without conversions to improve constructor resolution.
+        // E.g. `py::int_(1).cast<variant<double, int>>()` needs to fill the `int`
+        // slot of the variant. Without two-pass loading `double` would be filled
+        // because it appears first and a conversion is possible.
+        if (convert && load_alternative(src, false, type_list<Ts...>{})) {
+            return true;
+        }
+        return load_alternative(src, convert, type_list<Ts...>{});
+    }
+
+    template <typename Variant>
+    static handle cast(Variant &&src, return_value_policy policy, handle parent) {
+        return visit_helper<V>::call(variant_caster_visitor{policy, parent},
+                                     std::forward<Variant>(src));
+    }
+
+    using Type = V<Ts...>;
+    PYBIND11_TYPE_CASTER(Type,
+                         const_name("Union[") + detail::concat(make_caster<Ts>::name...)
+                             + const_name("]"));
+};
+
+#if defined(PYBIND11_HAS_VARIANT)
+template <typename... Ts>
+struct type_caster<std::variant<Ts...>> : variant_caster<std::variant<Ts...>> {};
+
+template <>
+struct type_caster<std::monostate> : public void_caster<std::monostate> {};
+#endif
+
+PYBIND11_NAMESPACE_END(detail)
+
+inline std::ostream &operator<<(std::ostream &os, const handle &obj) {
+#ifdef PYBIND11_HAS_STRING_VIEW
+    os << str(obj).cast<std::string_view>();
+#else
+    os << (std::string) str(obj);
+#endif
+    return os;
+}
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/stl/filesystem.h

@@ -0,0 +1,116 @@
+// Copyright (c) 2021 The Pybind Development Team.
+// All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#pragma once
+
+#include "../pybind11.h"
+#include "../detail/common.h"
+#include "../detail/descr.h"
+#include "../cast.h"
+#include "../pytypes.h"
+
+#include <string>
+
+#ifdef __has_include
+#    if defined(PYBIND11_CPP17)
+#        if __has_include(<filesystem>) && \
+          PY_VERSION_HEX >= 0x03060000
+#            include <filesystem>
+#            define PYBIND11_HAS_FILESYSTEM 1
+#        elif __has_include(<experimental/filesystem>)
+#            include <experimental/filesystem>
+#            define PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM 1
+#        endif
+#    endif
+#endif
+
+#if !defined(PYBIND11_HAS_FILESYSTEM) && !defined(PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM)           \
+    && !defined(PYBIND11_HAS_FILESYSTEM_IS_OPTIONAL)
+#    error                                                                                        \
+        "Neither #include <filesystem> nor #include <experimental/filesystem is available. (Use -DPYBIND11_HAS_FILESYSTEM_IS_OPTIONAL to ignore.)"
+#endif
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+#if defined(PYBIND11_HAS_FILESYSTEM) || defined(PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM)
+template <typename T>
+struct path_caster {
+
+private:
+    static PyObject *unicode_from_fs_native(const std::string &w) {
+#    if !defined(PYPY_VERSION)
+        return PyUnicode_DecodeFSDefaultAndSize(w.c_str(), ssize_t(w.size()));
+#    else
+        // PyPy mistakenly declares the first parameter as non-const.
+        return PyUnicode_DecodeFSDefaultAndSize(const_cast<char *>(w.c_str()), ssize_t(w.size()));
+#    endif
+    }
+
+    static PyObject *unicode_from_fs_native(const std::wstring &w) {
+        return PyUnicode_FromWideChar(w.c_str(), ssize_t(w.size()));
+    }
+
+public:
+    static handle cast(const T &path, return_value_policy, handle) {
+        if (auto py_str = unicode_from_fs_native(path.native())) {
+            return module_::import("pathlib")
+                .attr("Path")(reinterpret_steal<object>(py_str))
+                .release();
+        }
+        return nullptr;
+    }
+
+    bool load(handle handle, bool) {
+        // PyUnicode_FSConverter and PyUnicode_FSDecoder normally take care of
+        // calling PyOS_FSPath themselves, but that's broken on PyPy (PyPy
+        // issue #3168) so we do it ourselves instead.
+        PyObject *buf = PyOS_FSPath(handle.ptr());
+        if (!buf) {
+            PyErr_Clear();
+            return false;
+        }
+        PyObject *native = nullptr;
+        if constexpr (std::is_same_v<typename T::value_type, char>) {
+            if (PyUnicode_FSConverter(buf, &native) != 0) {
+                if (auto *c_str = PyBytes_AsString(native)) {
+                    // AsString returns a pointer to the internal buffer, which
+                    // must not be free'd.
+                    value = c_str;
+                }
+            }
+        } else if constexpr (std::is_same_v<typename T::value_type, wchar_t>) {
+            if (PyUnicode_FSDecoder(buf, &native) != 0) {
+                if (auto *c_str = PyUnicode_AsWideCharString(native, nullptr)) {
+                    // AsWideCharString returns a new string that must be free'd.
+                    value = c_str; // Copies the string.
+                    PyMem_Free(c_str);
+                }
+            }
+        }
+        Py_XDECREF(native);
+        Py_DECREF(buf);
+        if (PyErr_Occurred()) {
+            PyErr_Clear();
+            return false;
+        }
+        return true;
+    }
+
+    PYBIND11_TYPE_CASTER(T, const_name("os.PathLike"));
+};
+
+#endif // PYBIND11_HAS_FILESYSTEM || defined(PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM)
+
+#if defined(PYBIND11_HAS_FILESYSTEM)
+template <>
+struct type_caster<std::filesystem::path> : public path_caster<std::filesystem::path> {};
+#elif defined(PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM)
+template <>
+struct type_caster<std::experimental::filesystem::path>
+    : public path_caster<std::experimental::filesystem::path> {};
+#endif
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/stl_bind.h

@@ -0,0 +1,851 @@
+/*
+    pybind11/std_bind.h: Binding generators for STL data types
+
+    Copyright (c) 2016 Sergey Lyskov and Wenzel Jakob
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "detail/common.h"
+#include "detail/type_caster_base.h"
+#include "cast.h"
+#include "operators.h"
+
+#include <algorithm>
+#include <sstream>
+#include <type_traits>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/* SFINAE helper class used by 'is_comparable */
+template <typename T>
+struct container_traits {
+    template <typename T2>
+    static std::true_type
+    test_comparable(decltype(std::declval<const T2 &>() == std::declval<const T2 &>()) *);
+    template <typename T2>
+    static std::false_type test_comparable(...);
+    template <typename T2>
+    static std::true_type test_value(typename T2::value_type *);
+    template <typename T2>
+    static std::false_type test_value(...);
+    template <typename T2>
+    static std::true_type test_pair(typename T2::first_type *, typename T2::second_type *);
+    template <typename T2>
+    static std::false_type test_pair(...);
+
+    static constexpr const bool is_comparable
+        = std::is_same<std::true_type, decltype(test_comparable<T>(nullptr))>::value;
+    static constexpr const bool is_pair
+        = std::is_same<std::true_type, decltype(test_pair<T>(nullptr, nullptr))>::value;
+    static constexpr const bool is_vector
+        = std::is_same<std::true_type, decltype(test_value<T>(nullptr))>::value;
+    static constexpr const bool is_element = !is_pair && !is_vector;
+};
+
+/* Default: is_comparable -> std::false_type */
+template <typename T, typename SFINAE = void>
+struct is_comparable : std::false_type {};
+
+/* For non-map data structures, check whether operator== can be instantiated */
+template <typename T>
+struct is_comparable<
+    T,
+    enable_if_t<container_traits<T>::is_element && container_traits<T>::is_comparable>>
+    : std::true_type {};
+
+/* For a vector/map data structure, recursively check the value type
+   (which is std::pair for maps) */
+template <typename T>
+struct is_comparable<T, enable_if_t<container_traits<T>::is_vector>>
+    : is_comparable<typename recursive_container_traits<T>::type_to_check_recursively> {};
+
+template <>
+struct is_comparable<recursive_bottom> : std::true_type {};
+
+/* For pairs, recursively check the two data types */
+template <typename T>
+struct is_comparable<T, enable_if_t<container_traits<T>::is_pair>> {
+    static constexpr const bool value = is_comparable<typename T::first_type>::value
+                                        && is_comparable<typename T::second_type>::value;
+};
+
+/* Fallback functions */
+template <typename, typename, typename... Args>
+void vector_if_copy_constructible(const Args &...) {}
+template <typename, typename, typename... Args>
+void vector_if_equal_operator(const Args &...) {}
+template <typename, typename, typename... Args>
+void vector_if_insertion_operator(const Args &...) {}
+template <typename, typename, typename... Args>
+void vector_modifiers(const Args &...) {}
+
+template <typename Vector, typename Class_>
+void vector_if_copy_constructible(enable_if_t<is_copy_constructible<Vector>::value, Class_> &cl) {
+    cl.def(init<const Vector &>(), "Copy constructor");
+}
+
+template <typename Vector, typename Class_>
+void vector_if_equal_operator(enable_if_t<is_comparable<Vector>::value, Class_> &cl) {
+    using T = typename Vector::value_type;
+
+    cl.def(self == self);
+    cl.def(self != self);
+
+    cl.def(
+        "count",
+        [](const Vector &v, const T &x) { return std::count(v.begin(), v.end(), x); },
+        arg("x"),
+        "Return the number of times ``x`` appears in the list");
+
+    cl.def(
+        "remove",
+        [](Vector &v, const T &x) {
+            auto p = std::find(v.begin(), v.end(), x);
+            if (p != v.end()) {
+                v.erase(p);
+            } else {
+                throw value_error();
+            }
+        },
+        arg("x"),
+        "Remove the first item from the list whose value is x. "
+        "It is an error if there is no such item.");
+
+    cl.def(
+        "__contains__",
+        [](const Vector &v, const T &x) { return std::find(v.begin(), v.end(), x) != v.end(); },
+        arg("x"),
+        "Return true the container contains ``x``");
+}
+
+// Vector modifiers -- requires a copyable vector_type:
+// (Technically, some of these (pop and __delitem__) don't actually require copyability, but it
+// seems silly to allow deletion but not insertion, so include them here too.)
+template <typename Vector, typename Class_>
+void vector_modifiers(
+    enable_if_t<is_copy_constructible<typename Vector::value_type>::value, Class_> &cl) {
+    using T = typename Vector::value_type;
+    using SizeType = typename Vector::size_type;
+    using DiffType = typename Vector::difference_type;
+
+    auto wrap_i = [](DiffType i, SizeType n) {
+        if (i < 0) {
+            i += n;
+        }
+        if (i < 0 || (SizeType) i >= n) {
+            throw index_error();
+        }
+        return i;
+    };
+
+    cl.def(
+        "append",
+        [](Vector &v, const T &value) { v.push_back(value); },
+        arg("x"),
+        "Add an item to the end of the list");
+
+    cl.def(init([](const iterable &it) {
+        auto v = std::unique_ptr<Vector>(new Vector());
+        v->reserve(len_hint(it));
+        for (handle h : it) {
+            v->push_back(h.cast<T>());
+        }
+        return v.release();
+    }));
+
+    cl.def(
+        "clear", [](Vector &v) { v.clear(); }, "Clear the contents");
+
+    cl.def(
+        "extend",
+        [](Vector &v, const Vector &src) { v.insert(v.end(), src.begin(), src.end()); },
+        arg("L"),
+        "Extend the list by appending all the items in the given list");
+
+    cl.def(
+        "extend",
+        [](Vector &v, const iterable &it) {
+            const size_t old_size = v.size();
+            v.reserve(old_size + len_hint(it));
+            try {
+                for (handle h : it) {
+                    v.push_back(h.cast<T>());
+                }
+            } catch (const cast_error &) {
+                v.erase(v.begin() + static_cast<typename Vector::difference_type>(old_size),
+                        v.end());
+                try {
+                    v.shrink_to_fit();
+                } catch (const std::exception &) {
+                    // Do nothing
+                }
+                throw;
+            }
+        },
+        arg("L"),
+        "Extend the list by appending all the items in the given list");
+
+    cl.def(
+        "insert",
+        [](Vector &v, DiffType i, const T &x) {
+            // Can't use wrap_i; i == v.size() is OK
+            if (i < 0) {
+                i += v.size();
+            }
+            if (i < 0 || (SizeType) i > v.size()) {
+                throw index_error();
+            }
+            v.insert(v.begin() + i, x);
+        },
+        arg("i"),
+        arg("x"),
+        "Insert an item at a given position.");
+
+    cl.def(
+        "pop",
+        [](Vector &v) {
+            if (v.empty()) {
+                throw index_error();
+            }
+            T t = std::move(v.back());
+            v.pop_back();
+            return t;
+        },
+        "Remove and return the last item");
+
+    cl.def(
+        "pop",
+        [wrap_i](Vector &v, DiffType i) {
+            i = wrap_i(i, v.size());
+            T t = std::move(v[(SizeType) i]);
+            v.erase(std::next(v.begin(), i));
+            return t;
+        },
+        arg("i"),
+        "Remove and return the item at index ``i``");
+
+    cl.def("__setitem__", [wrap_i](Vector &v, DiffType i, const T &t) {
+        i = wrap_i(i, v.size());
+        v[(SizeType) i] = t;
+    });
+
+    /// Slicing protocol
+    cl.def(
+        "__getitem__",
+        [](const Vector &v, const slice &slice) -> Vector * {
+            size_t start = 0, stop = 0, step = 0, slicelength = 0;
+
+            if (!slice.compute(v.size(), &start, &stop, &step, &slicelength)) {
+                throw error_already_set();
+            }
+
+            auto *seq = new Vector();
+            seq->reserve((size_t) slicelength);
+
+            for (size_t i = 0; i < slicelength; ++i) {
+                seq->push_back(v[start]);
+                start += step;
+            }
+            return seq;
+        },
+        arg("s"),
+        "Retrieve list elements using a slice object");
+
+    cl.def(
+        "__setitem__",
+        [](Vector &v, const slice &slice, const Vector &value) {
+            size_t start = 0, stop = 0, step = 0, slicelength = 0;
+            if (!slice.compute(v.size(), &start, &stop, &step, &slicelength)) {
+                throw error_already_set();
+            }
+
+            if (slicelength != value.size()) {
+                throw std::runtime_error(
+                    "Left and right hand size of slice assignment have different sizes!");
+            }
+
+            for (size_t i = 0; i < slicelength; ++i) {
+                v[start] = value[i];
+                start += step;
+            }
+        },
+        "Assign list elements using a slice object");
+
+    cl.def(
+        "__delitem__",
+        [wrap_i](Vector &v, DiffType i) {
+            i = wrap_i(i, v.size());
+            v.erase(v.begin() + i);
+        },
+        "Delete the list elements at index ``i``");
+
+    cl.def(
+        "__delitem__",
+        [](Vector &v, const slice &slice) {
+            size_t start = 0, stop = 0, step = 0, slicelength = 0;
+
+            if (!slice.compute(v.size(), &start, &stop, &step, &slicelength)) {
+                throw error_already_set();
+            }
+
+            if (step == 1 && false) {
+                v.erase(v.begin() + (DiffType) start, v.begin() + DiffType(start + slicelength));
+            } else {
+                for (size_t i = 0; i < slicelength; ++i) {
+                    v.erase(v.begin() + DiffType(start));
+                    start += step - 1;
+                }
+            }
+        },
+        "Delete list elements using a slice object");
+}
+
+// If the type has an operator[] that doesn't return a reference (most notably std::vector<bool>),
+// we have to access by copying; otherwise we return by reference.
+template <typename Vector>
+using vector_needs_copy
+    = negation<std::is_same<decltype(std::declval<Vector>()[typename Vector::size_type()]),
+                            typename Vector::value_type &>>;
+
+// The usual case: access and iterate by reference
+template <typename Vector, typename Class_>
+void vector_accessor(enable_if_t<!vector_needs_copy<Vector>::value, Class_> &cl) {
+    using T = typename Vector::value_type;
+    using SizeType = typename Vector::size_type;
+    using DiffType = typename Vector::difference_type;
+    using ItType = typename Vector::iterator;
+
+    auto wrap_i = [](DiffType i, SizeType n) {
+        if (i < 0) {
+            i += n;
+        }
+        if (i < 0 || (SizeType) i >= n) {
+            throw index_error();
+        }
+        return i;
+    };
+
+    cl.def(
+        "__getitem__",
+        [wrap_i](Vector &v, DiffType i) -> T & {
+            i = wrap_i(i, v.size());
+            return v[(SizeType) i];
+        },
+        return_value_policy::reference_internal // ref + keepalive
+    );
+
+    cl.def(
+        "__iter__",
+        [](Vector &v) {
+            return make_iterator<return_value_policy::reference_internal, ItType, ItType, T &>(
+                v.begin(), v.end());
+        },
+        keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
+    );
+}
+
+// The case for special objects, like std::vector<bool>, that have to be returned-by-copy:
+template <typename Vector, typename Class_>
+void vector_accessor(enable_if_t<vector_needs_copy<Vector>::value, Class_> &cl) {
+    using T = typename Vector::value_type;
+    using SizeType = typename Vector::size_type;
+    using DiffType = typename Vector::difference_type;
+    using ItType = typename Vector::iterator;
+    cl.def("__getitem__", [](const Vector &v, DiffType i) -> T {
+        if (i < 0) {
+            i += v.size();
+            if (i < 0) {
+                throw index_error();
+            }
+        }
+        auto i_st = static_cast<SizeType>(i);
+        if (i_st >= v.size()) {
+            throw index_error();
+        }
+        return v[i_st];
+    });
+
+    cl.def(
+        "__iter__",
+        [](Vector &v) {
+            return make_iterator<return_value_policy::copy, ItType, ItType, T>(v.begin(), v.end());
+        },
+        keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
+    );
+}
+
+template <typename Vector, typename Class_>
+auto vector_if_insertion_operator(Class_ &cl, std::string const &name)
+    -> decltype(std::declval<std::ostream &>() << std::declval<typename Vector::value_type>(),
+                void()) {
+    using size_type = typename Vector::size_type;
+
+    cl.def(
+        "__repr__",
+        [name](Vector &v) {
+            std::ostringstream s;
+            s << name << '[';
+            for (size_type i = 0; i < v.size(); ++i) {
+                s << v[i];
+                if (i != v.size() - 1) {
+                    s << ", ";
+                }
+            }
+            s << ']';
+            return s.str();
+        },
+        "Return the canonical string representation of this list.");
+}
+
+// Provide the buffer interface for vectors if we have data() and we have a format for it
+// GCC seems to have "void std::vector<bool>::data()" - doing SFINAE on the existence of data()
+// is insufficient, we need to check it returns an appropriate pointer
+template <typename Vector, typename = void>
+struct vector_has_data_and_format : std::false_type {};
+template <typename Vector>
+struct vector_has_data_and_format<
+    Vector,
+    enable_if_t<std::is_same<decltype(format_descriptor<typename Vector::value_type>::format(),
+                                      std::declval<Vector>().data()),
+                             typename Vector::value_type *>::value>> : std::true_type {};
+
+// [workaround(intel)] Separate function required here
+// Workaround as the Intel compiler does not compile the enable_if_t part below
+// (tested with icc (ICC) 2021.1 Beta 20200827)
+template <typename... Args>
+constexpr bool args_any_are_buffer() {
+    return detail::any_of<std::is_same<Args, buffer_protocol>...>::value;
+}
+
+// [workaround(intel)] Separate function required here
+// [workaround(msvc)] Can't use constexpr bool in return type
+
+// Add the buffer interface to a vector
+template <typename Vector, typename Class_, typename... Args>
+void vector_buffer_impl(Class_ &cl, std::true_type) {
+    using T = typename Vector::value_type;
+
+    static_assert(vector_has_data_and_format<Vector>::value,
+                  "There is not an appropriate format descriptor for this vector");
+
+    // numpy.h declares this for arbitrary types, but it may raise an exception and crash hard
+    // at runtime if PYBIND11_NUMPY_DTYPE hasn't been called, so check here
+    format_descriptor<T>::format();
+
+    cl.def_buffer([](Vector &v) -> buffer_info {
+        return buffer_info(v.data(),
+                           static_cast<ssize_t>(sizeof(T)),
+                           format_descriptor<T>::format(),
+                           1,
+                           {v.size()},
+                           {sizeof(T)});
+    });
+
+    cl.def(init([](const buffer &buf) {
+        auto info = buf.request();
+        if (info.ndim != 1 || info.strides[0] % static_cast<ssize_t>(sizeof(T))) {
+            throw type_error("Only valid 1D buffers can be copied to a vector");
+        }
+        if (!detail::compare_buffer_info<T>::compare(info)
+            || (ssize_t) sizeof(T) != info.itemsize) {
+            throw type_error("Format mismatch (Python: " + info.format
+                             + " C++: " + format_descriptor<T>::format() + ")");
+        }
+
+        T *p = static_cast<T *>(info.ptr);
+        ssize_t step = info.strides[0] / static_cast<ssize_t>(sizeof(T));
+        T *end = p + info.shape[0] * step;
+        if (step == 1) {
+            return Vector(p, end);
+        }
+        Vector vec;
+        vec.reserve((size_t) info.shape[0]);
+        for (; p != end; p += step) {
+            vec.push_back(*p);
+        }
+        return vec;
+    }));
+
+    return;
+}
+
+template <typename Vector, typename Class_, typename... Args>
+void vector_buffer_impl(Class_ &, std::false_type) {}
+
+template <typename Vector, typename Class_, typename... Args>
+void vector_buffer(Class_ &cl) {
+    vector_buffer_impl<Vector, Class_, Args...>(
+        cl, detail::any_of<std::is_same<Args, buffer_protocol>...>{});
+}
+
+PYBIND11_NAMESPACE_END(detail)
+
+//
+// std::vector
+//
+template <typename Vector, typename holder_type = std::unique_ptr<Vector>, typename... Args>
+class_<Vector, holder_type> bind_vector(handle scope, std::string const &name, Args &&...args) {
+    using Class_ = class_<Vector, holder_type>;
+
+    // If the value_type is unregistered (e.g. a converting type) or is itself registered
+    // module-local then make the vector binding module-local as well:
+    using vtype = typename Vector::value_type;
+    auto *vtype_info = detail::get_type_info(typeid(vtype));
+    bool local = !vtype_info || vtype_info->module_local;
+
+    Class_ cl(scope, name.c_str(), pybind11::module_local(local), std::forward<Args>(args)...);
+
+    // Declare the buffer interface if a buffer_protocol() is passed in
+    detail::vector_buffer<Vector, Class_, Args...>(cl);
+
+    cl.def(init<>());
+
+    // Register copy constructor (if possible)
+    detail::vector_if_copy_constructible<Vector, Class_>(cl);
+
+    // Register comparison-related operators and functions (if possible)
+    detail::vector_if_equal_operator<Vector, Class_>(cl);
+
+    // Register stream insertion operator (if possible)
+    detail::vector_if_insertion_operator<Vector, Class_>(cl, name);
+
+    // Modifiers require copyable vector value type
+    detail::vector_modifiers<Vector, Class_>(cl);
+
+    // Accessor and iterator; return by value if copyable, otherwise we return by ref + keep-alive
+    detail::vector_accessor<Vector, Class_>(cl);
+
+    cl.def(
+        "__bool__",
+        [](const Vector &v) -> bool { return !v.empty(); },
+        "Check whether the list is nonempty");
+
+    cl.def("__len__", &Vector::size);
+
+#if 0
+    // C++ style functions deprecated, leaving it here as an example
+    cl.def(init<size_type>());
+
+    cl.def("resize",
+         (void (Vector::*) (size_type count)) & Vector::resize,
+         "changes the number of elements stored");
+
+    cl.def("erase",
+        [](Vector &v, SizeType i) {
+        if (i >= v.size())
+            throw index_error();
+        v.erase(v.begin() + i);
+    }, "erases element at index ``i``");
+
+    cl.def("empty",         &Vector::empty,         "checks whether the container is empty");
+    cl.def("size",          &Vector::size,          "returns the number of elements");
+    cl.def("push_back", (void (Vector::*)(const T&)) &Vector::push_back, "adds an element to the end");
+    cl.def("pop_back",                               &Vector::pop_back, "removes the last element");
+
+    cl.def("max_size",      &Vector::max_size,      "returns the maximum possible number of elements");
+    cl.def("reserve",       &Vector::reserve,       "reserves storage");
+    cl.def("capacity",      &Vector::capacity,      "returns the number of elements that can be held in currently allocated storage");
+    cl.def("shrink_to_fit", &Vector::shrink_to_fit, "reduces memory usage by freeing unused memory");
+
+    cl.def("clear", &Vector::clear, "clears the contents");
+    cl.def("swap",   &Vector::swap, "swaps the contents");
+
+    cl.def("front", [](Vector &v) {
+        if (v.size()) return v.front();
+        else throw index_error();
+    }, "access the first element");
+
+    cl.def("back", [](Vector &v) {
+        if (v.size()) return v.back();
+        else throw index_error();
+    }, "access the last element ");
+
+#endif
+
+    return cl;
+}
+
+//
+// std::map, std::unordered_map
+//
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/* Fallback functions */
+template <typename, typename, typename... Args>
+void map_if_insertion_operator(const Args &...) {}
+template <typename, typename, typename... Args>
+void map_assignment(const Args &...) {}
+
+// Map assignment when copy-assignable: just copy the value
+template <typename Map, typename Class_>
+void map_assignment(
+    enable_if_t<is_copy_assignable<typename Map::mapped_type>::value, Class_> &cl) {
+    using KeyType = typename Map::key_type;
+    using MappedType = typename Map::mapped_type;
+
+    cl.def("__setitem__", [](Map &m, const KeyType &k, const MappedType &v) {
+        auto it = m.find(k);
+        if (it != m.end()) {
+            it->second = v;
+        } else {
+            m.emplace(k, v);
+        }
+    });
+}
+
+// Not copy-assignable, but still copy-constructible: we can update the value by erasing and
+// reinserting
+template <typename Map, typename Class_>
+void map_assignment(enable_if_t<!is_copy_assignable<typename Map::mapped_type>::value
+                                    && is_copy_constructible<typename Map::mapped_type>::value,
+                                Class_> &cl) {
+    using KeyType = typename Map::key_type;
+    using MappedType = typename Map::mapped_type;
+
+    cl.def("__setitem__", [](Map &m, const KeyType &k, const MappedType &v) {
+        // We can't use m[k] = v; because value type might not be default constructable
+        auto r = m.emplace(k, v);
+        if (!r.second) {
+            // value type is not copy assignable so the only way to insert it is to erase it
+            // first...
+            m.erase(r.first);
+            m.emplace(k, v);
+        }
+    });
+}
+
+template <typename Map, typename Class_>
+auto map_if_insertion_operator(Class_ &cl, std::string const &name)
+    -> decltype(std::declval<std::ostream &>() << std::declval<typename Map::key_type>()
+                                               << std::declval<typename Map::mapped_type>(),
+                void()) {
+
+    cl.def(
+        "__repr__",
+        [name](Map &m) {
+            std::ostringstream s;
+            s << name << '{';
+            bool f = false;
+            for (auto const &kv : m) {
+                if (f) {
+                    s << ", ";
+                }
+                s << kv.first << ": " << kv.second;
+                f = true;
+            }
+            s << '}';
+            return s.str();
+        },
+        "Return the canonical string representation of this map.");
+}
+
+template <typename KeyType>
+struct keys_view {
+    virtual size_t len() = 0;
+    virtual iterator iter() = 0;
+    virtual bool contains(const KeyType &k) = 0;
+    virtual bool contains(const object &k) = 0;
+    virtual ~keys_view() = default;
+};
+
+template <typename MappedType>
+struct values_view {
+    virtual size_t len() = 0;
+    virtual iterator iter() = 0;
+    virtual ~values_view() = default;
+};
+
+template <typename KeyType, typename MappedType>
+struct items_view {
+    virtual size_t len() = 0;
+    virtual iterator iter() = 0;
+    virtual ~items_view() = default;
+};
+
+template <typename Map, typename KeysView>
+struct KeysViewImpl : public KeysView {
+    explicit KeysViewImpl(Map &map) : map(map) {}
+    size_t len() override { return map.size(); }
+    iterator iter() override { return make_key_iterator(map.begin(), map.end()); }
+    bool contains(const typename Map::key_type &k) override { return map.find(k) != map.end(); }
+    bool contains(const object &) override { return false; }
+    Map &map;
+};
+
+template <typename Map, typename ValuesView>
+struct ValuesViewImpl : public ValuesView {
+    explicit ValuesViewImpl(Map &map) : map(map) {}
+    size_t len() override { return map.size(); }
+    iterator iter() override { return make_value_iterator(map.begin(), map.end()); }
+    Map &map;
+};
+
+template <typename Map, typename ItemsView>
+struct ItemsViewImpl : public ItemsView {
+    explicit ItemsViewImpl(Map &map) : map(map) {}
+    size_t len() override { return map.size(); }
+    iterator iter() override { return make_iterator(map.begin(), map.end()); }
+    Map &map;
+};
+
+PYBIND11_NAMESPACE_END(detail)
+
+template <typename Map, typename holder_type = std::unique_ptr<Map>, typename... Args>
+class_<Map, holder_type> bind_map(handle scope, const std::string &name, Args &&...args) {
+    using KeyType = typename Map::key_type;
+    using MappedType = typename Map::mapped_type;
+    using StrippedKeyType = detail::remove_cvref_t<KeyType>;
+    using StrippedMappedType = detail::remove_cvref_t<MappedType>;
+    using KeysView = detail::keys_view<StrippedKeyType>;
+    using ValuesView = detail::values_view<StrippedMappedType>;
+    using ItemsView = detail::items_view<StrippedKeyType, StrippedMappedType>;
+    using Class_ = class_<Map, holder_type>;
+
+    // If either type is a non-module-local bound type then make the map binding non-local as well;
+    // otherwise (e.g. both types are either module-local or converting) the map will be
+    // module-local.
+    auto *tinfo = detail::get_type_info(typeid(MappedType));
+    bool local = !tinfo || tinfo->module_local;
+    if (local) {
+        tinfo = detail::get_type_info(typeid(KeyType));
+        local = !tinfo || tinfo->module_local;
+    }
+
+    Class_ cl(scope, name.c_str(), pybind11::module_local(local), std::forward<Args>(args)...);
+    static constexpr auto key_type_descr = detail::make_caster<KeyType>::name;
+    static constexpr auto mapped_type_descr = detail::make_caster<MappedType>::name;
+    std::string key_type_name(key_type_descr.text), mapped_type_name(mapped_type_descr.text);
+
+    // If key type isn't properly wrapped, fall back to C++ names
+    if (key_type_name == "%") {
+        key_type_name = detail::type_info_description(typeid(KeyType));
+    }
+    // Similarly for value type:
+    if (mapped_type_name == "%") {
+        mapped_type_name = detail::type_info_description(typeid(MappedType));
+    }
+
+    // Wrap KeysView[KeyType] if it wasn't already wrapped
+    if (!detail::get_type_info(typeid(KeysView))) {
+        class_<KeysView> keys_view(
+            scope, ("KeysView[" + key_type_name + "]").c_str(), pybind11::module_local(local));
+        keys_view.def("__len__", &KeysView::len);
+        keys_view.def("__iter__",
+                      &KeysView::iter,
+                      keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
+        );
+        keys_view.def("__contains__",
+                      static_cast<bool (KeysView::*)(const KeyType &)>(&KeysView::contains));
+        // Fallback for when the object is not of the key type
+        keys_view.def("__contains__",
+                      static_cast<bool (KeysView::*)(const object &)>(&KeysView::contains));
+    }
+    // Similarly for ValuesView:
+    if (!detail::get_type_info(typeid(ValuesView))) {
+        class_<ValuesView> values_view(scope,
+                                       ("ValuesView[" + mapped_type_name + "]").c_str(),
+                                       pybind11::module_local(local));
+        values_view.def("__len__", &ValuesView::len);
+        values_view.def("__iter__",
+                        &ValuesView::iter,
+                        keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
+        );
+    }
+    // Similarly for ItemsView:
+    if (!detail::get_type_info(typeid(ItemsView))) {
+        class_<ItemsView> items_view(
+            scope,
+            ("ItemsView[" + key_type_name + ", ").append(mapped_type_name + "]").c_str(),
+            pybind11::module_local(local));
+        items_view.def("__len__", &ItemsView::len);
+        items_view.def("__iter__",
+                       &ItemsView::iter,
+                       keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
+        );
+    }
+
+    cl.def(init<>());
+
+    // Register stream insertion operator (if possible)
+    detail::map_if_insertion_operator<Map, Class_>(cl, name);
+
+    cl.def(
+        "__bool__",
+        [](const Map &m) -> bool { return !m.empty(); },
+        "Check whether the map is nonempty");
+
+    cl.def(
+        "__iter__",
+        [](Map &m) { return make_key_iterator(m.begin(), m.end()); },
+        keep_alive<0, 1>() /* Essential: keep map alive while iterator exists */
+    );
+
+    cl.def(
+        "keys",
+        [](Map &m) {
+            return std::unique_ptr<KeysView>(new detail::KeysViewImpl<Map, KeysView>(m));
+        },
+        keep_alive<0, 1>() /* Essential: keep map alive while view exists */
+    );
+
+    cl.def(
+        "values",
+        [](Map &m) {
+            return std::unique_ptr<ValuesView>(new detail::ValuesViewImpl<Map, ValuesView>(m));
+        },
+        keep_alive<0, 1>() /* Essential: keep map alive while view exists */
+    );
+
+    cl.def(
+        "items",
+        [](Map &m) {
+            return std::unique_ptr<ItemsView>(new detail::ItemsViewImpl<Map, ItemsView>(m));
+        },
+        keep_alive<0, 1>() /* Essential: keep map alive while view exists */
+    );
+
+    cl.def(
+        "__getitem__",
+        [](Map &m, const KeyType &k) -> MappedType & {
+            auto it = m.find(k);
+            if (it == m.end()) {
+                throw key_error();
+            }
+            return it->second;
+        },
+        return_value_policy::reference_internal // ref + keepalive
+    );
+
+    cl.def("__contains__", [](Map &m, const KeyType &k) -> bool {
+        auto it = m.find(k);
+        if (it == m.end()) {
+            return false;
+        }
+        return true;
+    });
+    // Fallback for when the object is not of the key type
+    cl.def("__contains__", [](Map &, const object &) -> bool { return false; });
+
+    // Assignment provided only if the type is copyable
+    detail::map_assignment<Map, Class_>(cl);
+
+    cl.def("__delitem__", [](Map &m, const KeyType &k) {
+        auto it = m.find(k);
+        if (it == m.end()) {
+            throw key_error();
+        }
+        m.erase(it);
+    });
+
+    cl.def("__len__", &Map::size);
+
+    return cl;
+}
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

3rdparty/pybind11/include/pybind11/type_caster_pyobject_ptr.h

@@ -0,0 +1,61 @@
+// Copyright (c) 2023 The pybind Community.
+
+#pragma once
+
+#include "detail/common.h"
+#include "detail/descr.h"
+#include "cast.h"
+#include "pytypes.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+template <>
+class type_caster<PyObject> {
+public:
+    static constexpr auto name = const_name("object"); // See discussion under PR #4601.
+
+    // This overload is purely to guard against accidents.
+    template <typename T,
+              detail::enable_if_t<!is_same_ignoring_cvref<T, PyObject *>::value, int> = 0>
+    static handle cast(T &&, return_value_policy, handle /*parent*/) {
+        static_assert(is_same_ignoring_cvref<T, PyObject *>::value,
+                      "Invalid C++ type T for to-Python conversion (type_caster<PyObject>).");
+        return nullptr; // Unreachable.
+    }
+
+    static handle cast(PyObject *src, return_value_policy policy, handle /*parent*/) {
+        if (src == nullptr) {
+            throw error_already_set();
+        }
+        if (PyErr_Occurred()) {
+            raise_from(PyExc_SystemError, "src != nullptr but PyErr_Occurred()");
+            throw error_already_set();
+        }
+        if (policy == return_value_policy::take_ownership) {
+            return src;
+        }
+        if (policy == return_value_policy::reference
+            || policy == return_value_policy::automatic_reference) {
+            return handle(src).inc_ref();
+        }
+        pybind11_fail("type_caster<PyObject>::cast(): unsupported return_value_policy: "
+                      + std::to_string(static_cast<int>(policy)));
+    }
+
+    bool load(handle src, bool) {
+        value = reinterpret_borrow<object>(src);
+        return true;
+    }
+
+    template <typename T>
+    using cast_op_type = PyObject *;
+
+    explicit operator PyObject *() { return value.ptr(); }
+
+private:
+    object value;
+};
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

CHANGES-3.3

@@ -15,7 +15,11 @@ This release contains contributions from (alphabetically by first name):
  - Anke Boersma
 
 ## Core ##
- - No changes yet
+ - Boost::Python is no longer a dependency, Calamares uses a bundled copy
+   of pybind11 instead. This speeds up compilation and reducese the
+   dependency tree a great deal. You can set `WITH_PYBIND11=OFF` in the
+   build to keep Boost::Python and all the binary-compatibility problems
+   it entails.
 
 ## Modules ##
  - All QML modules now have a Qt6-compatible set of QML files as well. (thanks Anke)

CMakeLists.txt

@@ -23,8 +23,9 @@
 #   WITH_<foo>      : try to enable <foo> (these usually default to ON). For
 #                     a list of WITH_<foo> grep CMakeCache.txt after running
 #                     CMake once. These affect the ABI offered by Calamares.
-#                       - PYTHON (enable Python Job modules)
+#                       - PYBIND11 (use bundled pybind11, default ON, needs WITH_PYTHON)
-#                       - QML (enable QML UI View modules)
+#                       - PYTHON (enable Python Job modules, default ON if Python is found)
+#                       - QML (enable QML UI View modules, default ON)
 #                       - QT6 (use Qt6 rather than Qt5, default to OFF)
 #                     The WITH_* options affect the ABI of Calamares: you must
 #                     build (C++) modules for Calamares with the same WITH_*
@@ -80,7 +81,8 @@ option(INSTALL_POLKIT "Install Polkit configuration" ON)
 option(INSTALL_COMPLETION "Install shell completions" OFF)
 # When adding WITH_* that affects the ABI offered by libcalamares,
 # also update libcalamares/CalamaresConfig.h.in
-option(WITH_PYTHON "Enable Python modules API (requires Boost.Python)." ON)
+option(WITH_PYBIND11 "Use bundled pybind11 instead o Boost::Python" ON)
+option(WITH_PYTHON "Enable Python modules API." ON)
 option(WITH_QML "Enable QML UI options." ON)
 option(WITH_QT6 "Use Qt6 instead of Qt5" OFF)
 #
@@ -446,25 +448,30 @@ else()
 endif()
 add_feature_info(yaml-schema BUILD_SCHEMA_TESTING "Validate YAML (config files) with schema.${_schema_explanation}")
 
-if(Python_Development_FOUND)
+if(NOT Python_Development_FOUND)
+    message(STATUS "Disabling Python modules")
+    set(WITH_PYTHON OFF)
+    set(WITH_PYBIND11 OFF)
+endif()
+
+if(WITH_PYTHON AND NOT WITH_PYBIND11)
     find_package(boost_python)
     if(NOT TARGET Boost::python)
         find_package(Boost ${BOOSTPYTHON_VERSION} COMPONENTS python)
-        set_package_properties(Boost PROPERTIES PURPOSE "Boost.Python is used for Python job modules.")
+        set_package_properties(Boost PROPERTIES
+            PURPOSE "Boost.Python is used for Python job modules (because WITH_PYBIND11 is OFF)."
+            TYPE REQUIRED
+        )
     else()
         message(STATUS "Found boost_python with target Boost::python")
         set(Boost_FOUND ON)
     endif()
 endif()
 
-if(NOT Python_Development_FOUND OR NOT Boost_FOUND)
-    message(STATUS "Disabling Boost::Python modules")
-    set(WITH_PYTHON OFF)
-endif()
-
 # Now we know the state of the ABI-options, copy them into "Calamares_"
 # prefixed variables, to match how the variables would-be-named
 # when building out-of-tree.
+set(Calamares_WITH_PYBIND11 ${WITH_PYBIND11})
 set(Calamares_WITH_PYTHON ${WITH_PYTHON})
 set(Calamares_WITH_QML ${WITH_QML})
 set(Calamares_WITH_QT6 ${WITH_QT6})
@@ -595,9 +602,13 @@ include(GNUInstallDirs)
 set(Calamares_LIBRARIES calamares)
 
 add_subdirectory(3rdparty/kdsingleapplication)
+if(WITH_PYBIND11)
+    add_subdirectory(3rdparty/pybind11)
+endif()
 add_subdirectory(src)
 
 add_feature_info(Python ${WITH_PYTHON} "Python job modules")
+add_feature_info(Pybind11 ${WITH_PYBIND11} "Python using bundled pybind11")
 add_feature_info(Qml ${WITH_QML} "QML UI support")
 add_feature_info(Polkit ${INSTALL_POLKIT} "Install Polkit files")
 add_feature_info(KCrash ${BUILD_CRASH_REPORTING} "Crash dumps via KCrash")

CONTRIBUTING.md

@@ -131,7 +131,7 @@ Main:
 * KDE extra-cmake-modules >= 5.78 (recommended; required for some modules;
   required for some tests)
 * Python >= 3.6 (required for some modules)
-* Boost.Python >= 1.72.0 (required for some modules)
+* Boost.Python >= 1.72.0 (required for some modules if WITH_PYBIND11 is OFF)
 
 Individual modules may have their own requirements;
 these are listed in CMake output.

ci/deps-opensuse-qt6.sh

@@ -11,7 +11,7 @@ zypper --non-interactive up
 zypper --non-interactive in git-core jq curl ninja
 # From deploycala.py
 zypper --non-interactive in bison flex git make cmake gcc-c++
-zypper --non-interactive in yaml-cpp-devel libpwquality-devel parted-devel python-devel libboost_headers-devel libboost_python3-devel
+zypper --non-interactive in yaml-cpp-devel libpwquality-devel parted-devel python3-devel
 zypper --non-interactive in libicu-devel libatasmart-devel
 # Qt6/KF6 dependencies
 zypper --non-interactive in qt6-concurrent-devel qt6-gui-devel qt6-linguist-devel qt6-network-devel qt6-svg-devel qt6-declarative-devel

src/calamares/CMakeLists.txt

@@ -64,4 +64,9 @@ if(BUILD_TESTING)
 
     add_executable(test_conf test_conf.cpp)
     target_link_libraries(test_conf PUBLIC yamlcpp::yamlcpp ${qtname}::Core)
+
+    if(WITH_PYBIND11)
+        target_compile_definitions(loadmodule PRIVATE WITH_PYBIND11=1)
+    endif()
+
 endif()

src/calamares/testmain.cpp

@@ -25,15 +25,21 @@
 #include "modulesystem/ViewModule.h"
 #include "utils/Logger.h"
 #include "utils/Retranslator.h"
+#include "utils/System.h"
 #include "utils/Yaml.h"
 #include "viewpages/ExecutionViewStep.h"
 
 // Optional features of Calamares
-// - Python support
+// - Python support with pybind11
+// - Python support with older Boost implementation
 // - QML support
 #ifdef WITH_PYTHON
+#if WITH_PYBIND11
+#include "python/PythonJob.h"
+#else
 #include "PythonJob.h"
 #endif
+#endif
 #ifdef WITH_QML
 #include "utils/Qml.h"
 #endif
@@ -59,6 +65,7 @@ struct ModuleConfig
     QString m_module;
     QString m_jobConfig;
     QString m_globalConfig;
+    QString m_settingsConfig;
     QString m_language;
     QString m_branding;
     bool m_ui;
@@ -70,8 +77,11 @@ handle_args( QCoreApplication& a )
 {
     QCommandLineOption debugLevelOption(
         QStringLiteral( "D" ), "Verbose output for debugging purposes (0-8), ignored.", "level" );
+    QCommandLineOption settingsOption( { QStringLiteral( "S" ), QStringLiteral( "settings" ) },
+                                       QStringLiteral( "Settings.conf document" ),
+                                       QString( "settings.conf" ) );
     QCommandLineOption globalOption( { QStringLiteral( "g" ), QStringLiteral( "global" ) },
-                                     QStringLiteral( "Global settings document" ),
+                                     QStringLiteral( "Global storage settings document" ),
                                      "global.yaml" );
     QCommandLineOption jobOption(
         { QStringLiteral( "j" ), QStringLiteral( "job" ) }, QStringLiteral( "Job settings document" ), "job.yaml" );
@@ -91,6 +101,7 @@ handle_args( QCoreApplication& a )
     parser.addVersionOption();
 
     parser.addOption( debugLevelOption );
+    parser.addOption( settingsOption );
     parser.addOption( globalOption );
     parser.addOption( jobOption );
     parser.addOption( langOption );
@@ -137,6 +148,7 @@ handle_args( QCoreApplication& a )
         return ModuleConfig { parser.isSet( slideshowOption ) ? QStringLiteral( "-" ) : args.first(),
                               jobSettings,
                               parser.value( globalOption ),
+                              parser.value( settingsOption ),
                               parser.value( langOption ),
                               parser.value( brandOption ),
                               parser.isSet( slideshowOption ) || parser.isSet( uiOption ),
@@ -453,8 +465,10 @@ main( int argc, char* argv[] )
         return 1;
     }
 
-    std::unique_ptr< Calamares::Settings > settings_p( Calamares::Settings::init( QString() ) );
+    std::unique_ptr< Calamares::Settings > settings_p( Calamares::Settings::init( module.m_settingsConfig ) );
     std::unique_ptr< Calamares::JobQueue > jobqueue_p( new Calamares::JobQueue( nullptr ) );
+    std::unique_ptr< Calamares::System > system_p( new Calamares::System( settings_p->doChroot() ) );
+
     QMainWindow* mw = nullptr;
 
     auto* gs = jobqueue_p->globalStorage();
@@ -472,7 +486,12 @@ main( int argc, char* argv[] )
 #ifdef WITH_PYTHON
     if ( module.m_pythonInjection )
     {
+#if WITH_PYBIND11
+        Calamares::Python::Job::setInjectedPreScript( pythonPreScript );
+#else
+        // Old Boost approach
         Calamares::PythonJob::setInjectedPreScript( pythonPreScript );
+#endif
     }
 #endif
 #ifdef WITH_QML

src/libcalamares/CMakeLists.txt

@@ -115,8 +115,13 @@ endif()
 #
 #
 if(WITH_PYTHON)
-    target_sources(calamares PRIVATE PythonHelper.cpp PythonJob.cpp PythonJobApi.cpp)
+    if(WITH_PYBIND11)
-    target_link_libraries(calamares PRIVATE Python::Python Boost::python)
+        target_sources(calamares PRIVATE python/Api.cpp python/PythonJob.cpp)
+        target_link_libraries(calamares PRIVATE Python::Python pybind11::headers)
+    else()
+        target_sources(calamares PRIVATE PythonHelper.cpp PythonJob.cpp PythonJobApi.cpp)
+        target_link_libraries(calamares PRIVATE Python::Python Boost::python)
+    endif()
 endif()
 
 ### OPTIONAL GeoIP XML support

src/libcalamares/python/Api.cpp

@@ -0,0 +1,647 @@
+/* === This file is part of Calamares - <https://calamares.io> ===
+ *
+ *   SPDX-FileCopyrightText: 2014 Teo Mrnjavac <teo@kde.org>
+ *   SPDX-FileCopyrightText: 2017-2020, 2023 Adriaan de Groot <groot@kde.org>
+ *   SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ *   Calamares is Free Software: see the License-Identifier above.
+ *
+ */
+#include "python/Api.h"
+
+#include "CalamaresVersion.h"
+#include "GlobalStorage.h"
+#include "JobQueue.h"
+#include "compat/Variant.h"
+#include "locale/Global.h"
+#include "python/PythonJob.h"
+#include "utils/Logger.h"
+#include "utils/RAII.h"
+#include "utils/Runner.h"
+#include "utils/String.h"
+#include "utils/System.h"
+#include "utils/Yaml.h"
+
+#include <QCoreApplication>
+#include <QDir>
+#include <QStandardPaths>
+
+#undef slots
+#include <pybind11/embed.h>
+#include <pybind11/pybind11.h>
+
+namespace py = pybind11;
+
+/** @namespace
+ *
+ * Helper functions for converting Python (pybind11) types to Qt types.
+ */
+namespace
+{
+// Forward declarations, since most of these are mutually recursive
+Calamares::Python::List variantListToPyList( const QVariantList& variantList );
+Calamares::Python::Dictionary variantMapToPyDict( const QVariantMap& variantMap );
+Calamares::Python::Dictionary variantHashToPyDict( const QVariantHash& variantHash );
+
+py::object
+variantToPyObject( const QVariant& variant )
+{
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wswitch-enum"
+#endif
+
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+    const auto IntVariantType = QVariant::Int;
+    const auto UIntVariantType = QVariant::UInt;
+#else
+    const auto IntVariantType = QMetaType::Type::Int;
+    const auto UIntVariantType = QMetaType::Type::UInt;
+#endif
+    // 49 enumeration values not handled
+    switch ( Calamares::typeOf( variant ) )
+    {
+    case Calamares::MapVariantType:
+        return variantMapToPyDict( variant.toMap() );
+
+    case Calamares::HashVariantType:
+        return variantHashToPyDict( variant.toHash() );
+
+    case Calamares::ListVariantType:
+    case Calamares::StringListVariantType:
+        return variantListToPyList( variant.toList() );
+
+    case IntVariantType:
+        return py::int_( variant.toInt() );
+    case UIntVariantType:
+        return py::int_( variant.toUInt() );
+
+    case Calamares::LongLongVariantType:
+        return py::int_( variant.toLongLong() );
+    case Calamares::ULongLongVariantType:
+        return py::int_( variant.toULongLong() );
+
+    case Calamares::DoubleVariantType:
+        return py::float_( variant.toDouble() );
+
+    case Calamares::CharVariantType:
+#if QT_VERSION > QT_VERSION_CHECK( 6, 0, 0 )
+    case QMetaType::Type::QChar:
+#endif
+    case Calamares::StringVariantType:
+        return Calamares::Python::String( variant.toString().toStdString() );
+
+    case Calamares::BoolVariantType:
+        return py::bool_( variant.toBool() );
+
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+    case QVariant::Invalid:
+#endif
+    default:
+        return py::object();
+    }
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+}
+
+Calamares::Python::List
+variantListToPyList( const QVariantList& variantList )
+{
+    Calamares::Python::List pyList;
+    for ( const QVariant& variant : variantList )
+    {
+        pyList.append( variantToPyObject( variant ) );
+    }
+    return pyList;
+}
+
+Calamares::Python::Dictionary
+variantMapToPyDict( const QVariantMap& variantMap )
+{
+    Calamares::Python::Dictionary pyDict;
+    for ( auto it = variantMap.constBegin(); it != variantMap.constEnd(); ++it )
+    {
+        pyDict[ Calamares::Python::String( it.key().toStdString() ) ] = variantToPyObject( it.value() );
+    }
+    return pyDict;
+}
+
+Calamares::Python::Dictionary
+variantHashToPyDict( const QVariantHash& variantHash )
+{
+    Calamares::Python::Dictionary pyDict;
+    for ( auto it = variantHash.constBegin(); it != variantHash.constEnd(); ++it )
+    {
+        pyDict[ Calamares::Python::String( it.key().toStdString() ) ] = variantToPyObject( it.value() );
+    }
+    return pyDict;
+}
+
+QVariantList variantListFromPyList( const Calamares::Python::List& list );
+QVariantMap variantMapFromPyDict( const Calamares::Python::Dictionary& dict );
+
+QVariant
+variantFromPyObject( const py::handle& o )
+{
+    if ( py::isinstance< Calamares::Python::Dictionary >( o ) )
+    {
+        return variantMapFromPyDict( py::cast< Calamares::Python::Dictionary >( o ) );
+    }
+    else if ( py::isinstance< Calamares::Python::List >( o ) )
+    {
+        return variantListFromPyList( py::cast< Calamares::Python::List >( o ) );
+    }
+    else if ( py::isinstance< py::int_ >( o ) )
+    {
+        return QVariant( qlonglong( py::cast< py::int_ >( o ) ) );
+    }
+    else if ( py::isinstance< py::float_ >( o ) )
+    {
+        return QVariant( double( py::cast< py::float_ >( o ) ) );
+    }
+    else if ( py::isinstance< py::str >( o ) )
+    {
+        return QVariant( QString::fromStdString( std::string( py::str( o ) ) ) );
+    }
+    else if ( py::isinstance< py::bool_ >( o ) )
+    {
+        return QVariant( bool( py::cast< py::bool_ >( o ) ) );
+    }
+
+    return QVariant();
+}
+
+QVariantList
+variantListFromPyList( const Calamares::Python::List& list )
+{
+    QVariantList l;
+    for ( const auto& h : list )
+    {
+        l.append( variantFromPyObject( h ) );
+    }
+    return l;
+}
+
+QVariantMap
+variantMapFromPyDict( const Calamares::Python::Dictionary& dict )
+{
+    QVariantMap m;
+    for ( const auto& item : dict )
+    {
+        m.insert( Calamares::Python::asQString( item.first ), variantFromPyObject( ( item.second ) ) );
+    }
+    return m;
+}
+
+QStringList
+stringListFromPyList( const Calamares::Python::List& list )
+{
+    QStringList l;
+    for ( const auto& h : list )
+    {
+        l.append( Calamares::Python::asQString( h ) );
+    }
+    return l;
+}
+
+const char output_prefix[] = "[PYTHON JOB]:";
+inline void
+log_action( unsigned int level, const std::string& s )
+{
+    Logger::CDebug( level ) << output_prefix << QString::fromStdString( s );
+}
+
+static Calamares::GlobalStorage*
+_global_storage()
+{
+    static Calamares::GlobalStorage* p = new Calamares::GlobalStorage;
+    return p;
+}
+
+static QStringList
+_gettext_languages()
+{
+    QStringList languages;
+
+    // There are two ways that Python jobs can be initialised:
+    //  - through JobQueue, in which case that has an instance which holds
+    //    a GlobalStorage object, or
+    //  - through the Python test-script, which initialises its
+    //    own GlobalStorageProxy, which then holds a
+    //    GlobalStorage object for all of Python.
+    Calamares::JobQueue* jq = Calamares::JobQueue::instance();
+    Calamares::GlobalStorage* gs = jq ? jq->globalStorage() : _global_storage();
+
+    QString lang = Calamares::Locale::readGS( *gs, QStringLiteral( "LANG" ) );
+    if ( !lang.isEmpty() )
+    {
+        languages.append( lang );
+        if ( lang.indexOf( '.' ) > 0 )
+        {
+            lang.truncate( lang.indexOf( '.' ) );
+            languages.append( lang );
+        }
+        if ( lang.indexOf( '_' ) > 0 )
+        {
+            lang.truncate( lang.indexOf( '_' ) );
+            languages.append( lang );
+        }
+    }
+    return languages;
+}
+
+static void
+_add_localedirs( QStringList& pathList, const QString& candidate )
+{
+    if ( !candidate.isEmpty() && !pathList.contains( candidate ) )
+    {
+        pathList.prepend( candidate );
+        if ( QDir( candidate ).cd( "lang" ) )
+        {
+            pathList.prepend( candidate + "/lang" );
+        }
+    }
+}
+
+int
+raise_on_error( const Calamares::ProcessResult& ec, const QStringList& commandList )
+{
+    if ( ec.first == 0 )
+    {
+        return 0;
+    }
+
+    QString raise = QString( "import subprocess\n"
+                             "e = subprocess.CalledProcessError(%1,\"%2\")\n" )
+                        .arg( ec.first )
+                        .arg( commandList.join( ' ' ) );
+    if ( !ec.second.isEmpty() )
+    {
+        raise.append( QStringLiteral( "e.output = \"\"\"%1\"\"\"\n" ).arg( ec.second ) );
+    }
+    raise.append( "raise e" );
+    py::exec( raise.toStdString() );
+    py::error_already_set();
+    return ec.first;
+}
+
+int
+process_output( Calamares::Utils::RunLocation location,
+                const QStringList& args,
+                const Calamares::Python::Object& callback,
+                const std::string& input,
+                int timeout )
+{
+    Calamares::Utils::Runner r( args );
+    r.setLocation( location );
+    if ( !callback.is_none() )
+    {
+        if ( py::isinstance< Calamares::Python::List >( callback ) )
+        {
+            QObject::connect( &r,
+                              &decltype( r )::output,
+                              [ list_append = callback.attr( "append" ) ]( const QString& s )
+                              { list_append( s.toStdString() ); } );
+        }
+        else
+        {
+            QObject::connect(
+                &r, &decltype( r )::output, [ &callback ]( const QString& s ) { callback( s.toStdString() ); } );
+        }
+        r.enableOutputProcessing();
+    }
+    if ( !input.empty() )
+    {
+        r.setInput( QString::fromStdString( input ) );
+    }
+    if ( timeout > 0 )
+    {
+        r.setTimeout( std::chrono::seconds( timeout ) );
+    }
+
+    auto result = r.run();
+    return raise_on_error( result, args );
+}
+
+}  // namespace
+
+/** @namespace
+ *
+ * This is where the "public Python API" lives. It does not need to
+ * be a namespace, and it does not need to be public, but it's
+ * convenient to group things together.
+ */
+namespace Calamares
+{
+namespace Python
+{
+
+std::string
+obscure( const std::string& string )
+{
+    return Calamares::String::obscure( QString::fromStdString( string ) ).toStdString();
+}
+
+void
+debug( const std::string& s )
+{
+    log_action( Logger::LOGDEBUG, s );
+}
+
+void
+warning( const std::string& s )
+{
+    log_action( Logger::LOGWARNING, s );
+}
+
+void
+error( const std::string& s )
+{
+    log_action( Logger::LOGERROR, s );
+}
+
+Dictionary
+load_yaml( const std::string& path )
+{
+    const QString filePath = QString::fromUtf8( path.c_str() );
+    bool ok = false;
+    auto map = Calamares::YAML::load( filePath, &ok );
+    if ( !ok )
+    {
+        cWarning() << "Loading YAML from" << filePath << "failed.";
+    }
+
+    return variantMapToPyDict( map );
+}
+
+py::list
+gettext_languages()
+{
+    py::list pyList;
+    for ( auto lang : _gettext_languages() )
+    {
+        pyList.append( lang.toStdString() );
+    }
+    return pyList;
+}
+
+py::object
+gettext_path()
+{
+    // Going to log informatively just once
+    static bool first_time = true;
+    cScopedAssignment( &first_time, false );
+
+    // TODO: distinguish between -d runs and normal runs
+    // TODO: can we detect DESTDIR-installs?
+    QStringList candidatePaths
+        = QStandardPaths::locateAll( QStandardPaths::GenericDataLocation, "locale", QStandardPaths::LocateDirectory );
+    QString extra = QCoreApplication::applicationDirPath();
+    _add_localedirs( candidatePaths, extra );  // Often /usr/local/bin
+    if ( !extra.isEmpty() )
+    {
+        QDir d( extra );
+        if ( d.cd( "../share/locale" ) )  // Often /usr/local/bin/../share/locale -> /usr/local/share/locale
+        {
+            _add_localedirs( candidatePaths, d.canonicalPath() );
+        }
+    }
+    _add_localedirs( candidatePaths, QDir().canonicalPath() );  // .
+
+    if ( first_time )
+    {
+        cDebug() << "Determining gettext path from" << candidatePaths;
+    }
+
+    QStringList candidateLanguages = _gettext_languages();
+    for ( const auto& lang : candidateLanguages )
+    {
+        for ( auto localedir : candidatePaths )
+        {
+            QDir ldir( localedir );
+            if ( ldir.cd( lang ) )
+            {
+                Logger::CDebug( Logger::LOGDEBUG )
+                    << output_prefix << "Found gettext" << lang << "in" << ldir.canonicalPath();
+                return String( localedir.toStdString() );
+            }
+        }
+    }
+    cWarning() << "No translation found for languages" << candidateLanguages;
+    return py::none();  // None
+}
+
+int
+target_env_call( const List& args, const std::string& input, int timeout )
+{
+    return Calamares::System::instance()
+        ->targetEnvCommand(
+            stringListFromPyList( args ), QString(), QString::fromStdString( input ), std::chrono::seconds( timeout ) )
+        .first;
+}
+
+int
+check_target_env_call( const List& args, const std::string& input, int timeout )
+{
+    const auto commandList = stringListFromPyList( args );
+    auto ec = Calamares::System::instance()->targetEnvCommand(
+        commandList, QString(), QString::fromStdString( input ), std::chrono::seconds( timeout ) );
+    return raise_on_error( ec, commandList );
+}
+
+std::string
+check_target_env_output( const List& args, const std::string& input, int timeout )
+{
+    const auto commandList = stringListFromPyList( args );
+    auto ec = Calamares::System::instance()->targetEnvCommand(
+        commandList, QString(), QString::fromStdString( input ), std::chrono::seconds( timeout ) );
+    raise_on_error( ec, commandList );
+    return ec.second.toStdString();
+}
+
+int
+target_env_process_output( const List& args, const Object& callback, const std::string& input, int timeout )
+{
+    return process_output(
+        Calamares::System::RunLocation::RunInTarget, stringListFromPyList( args ), callback, input, timeout );
+}
+int
+host_env_process_output( const List& args, const Object& callback, const std::string& input, int timeout )
+{
+    return process_output(
+        Calamares::System::RunLocation::RunInHost, stringListFromPyList( args ), callback, input, timeout );
+}
+
+
+JobProxy::JobProxy( Calamares::Python::Job* parent )
+    : prettyName( parent->prettyName().toStdString() )
+    , workingPath( parent->workingPath().toStdString() )
+    , moduleName( QDir( parent->workingPath() ).dirName().toStdString() )
+    , configuration( variantMapToPyDict( parent->configuration() ) )
+    , m_parent( parent )
+{
+}
+
+void
+JobProxy::setprogress( qreal progress )
+{
+    if ( progress >= 0.0 && progress <= 1.0 )
+    {
+        m_parent->emitProgress( progress );
+    }
+}
+
+
+Calamares::GlobalStorage* GlobalStorageProxy::s_gs_instance = nullptr;
+
+// The special handling for nullptr is only for the testing
+// script for the python bindings, which passes in None;
+// normal use will have a GlobalStorage from JobQueue::instance()
+// passed in. Testing use will leak the allocated GlobalStorage
+// object, but that's OK for testing.
+GlobalStorageProxy::GlobalStorageProxy( Calamares::GlobalStorage* gs )
+    : m_gs( gs ? gs : s_gs_instance )
+{
+    if ( !m_gs )
+    {
+        s_gs_instance = new Calamares::GlobalStorage;
+        m_gs = s_gs_instance;
+    }
+}
+
+bool
+GlobalStorageProxy::contains( const std::string& key ) const
+{
+    return m_gs->contains( QString::fromStdString( key ) );
+}
+
+int
+GlobalStorageProxy::count() const
+{
+    return m_gs->count();
+}
+
+void
+GlobalStorageProxy::insert( const std::string& key, const Object& value )
+{
+    m_gs->insert( QString::fromStdString( key ), variantFromPyObject( value ) );
+}
+
+List
+GlobalStorageProxy::keys() const
+{
+    List pyList;
+    const auto keys = m_gs->keys();
+    for ( const QString& key : keys )
+    {
+        pyList.append( key.toStdString() );
+    }
+    return pyList;
+}
+
+int
+GlobalStorageProxy::remove( const std::string& key )
+{
+    const QString gsKey( QString::fromStdString( key ) );
+    if ( !m_gs->contains( gsKey ) )
+    {
+        cWarning() << "Unknown GS key" << key.c_str();
+    }
+    return m_gs->remove( gsKey );
+}
+
+Object
+GlobalStorageProxy::value( const std::string& key ) const
+{
+    const QString gsKey( QString::fromStdString( key ) );
+    if ( !m_gs->contains( gsKey ) )
+    {
+        cWarning() << "Unknown GS key" << key.c_str();
+        return py::none();
+    }
+    return variantToPyObject( m_gs->value( gsKey ) );
+}
+
+}  // namespace Python
+}  // namespace Calamares
+
+PYBIND11_EMBEDDED_MODULE( utils, m )
+{
+    m.doc() = "Calamares Utility API for Python";
+
+    m.def( "obscure", &Calamares::Python::obscure, "A function that obscures (encodes) a string" );
+
+    m.def( "debug", &Calamares::Python::debug, "Log a debug-message" );
+    m.def( "warn", &Calamares::Python::warning, "Log a warning-message" );
+    m.def( "warning", &Calamares::Python::warning, "Log a warning-message" );
+    m.def( "error", &Calamares::Python::error, "Log an error-message" );
+
+    m.def( "load_yaml", &Calamares::Python::load_yaml, "Loads YAML from a file." );
+
+    m.def( "target_env_call",
+           &Calamares::Python::target_env_call,
+           "Runs command in target, returns exit code.",
+           py::arg( "command_list" ),
+           py::arg( "input" ) = std::string(),
+           py::arg( "timeout" ) = 0 );
+    m.def( "check_target_env_call",
+           &Calamares::Python::check_target_env_call,
+           "Runs command in target, raises on error exit.",
+           py::arg( "command_list" ),
+           py::arg( "input" ) = std::string(),
+           py::arg( "timeout" ) = 0 );
+    m.def( "check_target_env_output",
+           &Calamares::Python::check_target_env_output,
+           "Runs command in target, returns standard output or raises on error.",
+           py::arg( "command_list" ),
+           py::arg( "input" ) = std::string(),
+           py::arg( "timeout" ) = 0 );
+    m.def( "target_env_process_output",
+           &Calamares::Python::target_env_process_output,
+           "Runs command in target, updating callback and returns standard output or raises on error.",
+           py::arg( "command_list" ),
+           py::arg( "callback" ) = pybind11::none(),
+           py::arg( "input" ) = std::string(),
+           py::arg( "timeout" ) = 0 );
+    m.def( "host_env_process_output",
+           &Calamares::Python::host_env_process_output,
+           "Runs command in target, updating callback and returns standard output or raises on error.",
+           py::arg( "command_list" ),
+           py::arg( "callback" ) = pybind11::none(),
+           py::arg( "input" ) = std::string(),
+           py::arg( "timeout" ) = 0 );
+
+    m.def( "gettext_languages",
+           &Calamares::Python::gettext_languages,
+           "Returns list of languages (most to least-specific) for gettext." );
+    m.def( "gettext_path", &Calamares::Python::gettext_path, "Returns path for gettext search." );
+}
+
+PYBIND11_MODULE( libcalamares, m )
+{
+    m.doc() = "Calamares API for Python";
+
+    m.add_object( "ORGANIZATION_NAME", Calamares::Python::String( CALAMARES_ORGANIZATION_NAME ) );
+    m.add_object( "ORGANIZATION_DOMAIN", Calamares::Python::String( CALAMARES_ORGANIZATION_DOMAIN ) );
+    m.add_object( "APPLICATION_NAME", Calamares::Python::String( CALAMARES_APPLICATION_NAME ) );
+    m.add_object( "VERSION", Calamares::Python::String( CALAMARES_VERSION ) );
+    m.add_object( "VERSION_SHORT", Calamares::Python::String( CALAMARES_VERSION_SHORT ) );
+
+    m.add_object( "utils", py::module::import( "utils" ) );
+
+    py::class_< Calamares::Python::JobProxy >( m, "Job" )
+        .def_readonly( "module_name", &Calamares::Python::JobProxy::moduleName )
+        .def_readonly( "pretty_name", &Calamares::Python::JobProxy::prettyName )
+        .def_readonly( "working_path", &Calamares::Python::JobProxy::workingPath )
+        .def_readonly( "configuration", &Calamares::Python::JobProxy::configuration )
+        .def( "setprogress", &Calamares::Python::JobProxy::setprogress );
+
+    py::class_< Calamares::Python::GlobalStorageProxy >( m, "GlobalStorage" )
+        .def( "contains", &Calamares::Python::GlobalStorageProxy::contains )
+        .def( "count", &Calamares::Python::GlobalStorageProxy::count )
+        .def( "insert", &Calamares::Python::GlobalStorageProxy::insert )
+        .def( "keys", &Calamares::Python::GlobalStorageProxy::keys )
+        .def( "remove", &Calamares::Python::GlobalStorageProxy::remove )
+        .def( "value", &Calamares::Python::GlobalStorageProxy::value );
+}

src/libcalamares/python/Api.h

@@ -0,0 +1,100 @@
+/* === This file is part of Calamares - <https://calamares.io> ===
+ *
+ *   SPDX-FileCopyrightText: 2023 Adriaan de Groot <groot@kde.org>
+ *   SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ *   Calamares is Free Software: see the License-Identifier above.
+ *
+ */
+
+#ifndef CALAMARES_PYTHON_API_H
+#define CALAMARES_PYTHON_API_H
+
+/** @file
+ *
+ * Contains the API that Python modules use from the Python code
+ * of that module. This is the C++ side that implements the functions
+ * imported by the Python code as `import libcalamares`.
+ */
+
+#include "python/Pybind11Helpers.h"
+
+#include <string>
+
+namespace Calamares
+{
+
+class GlobalStorage;
+class PythonJob;
+
+namespace Python __attribute__( ( visibility( "hidden" ) ) )
+{
+    std::string obscure( const std::string& string );
+
+    void debug( const std::string& s );
+    void warning( const std::string& s );
+    // void warn( const std::string& s) is an alias of warning()
+    void error( const std::string& s );
+
+    Dictionary load_yaml( const std::string& path );
+
+    List gettext_languages();
+    Object gettext_path();
+
+    int target_env_call( const List& args, const std::string& input, int timeout );
+    int check_target_env_call( const List& args, const std::string& input, int timeout );
+    std::string check_target_env_output( const List& args, const std::string& input, int timeout );
+
+    int target_env_process_output( const List& args, const Object& callback, const std::string& input, int timeout );
+    int host_env_process_output( const List& args, const Object& callback, const std::string& input, int timeout );
+
+
+    class Job;
+    /** @brief Proxy class in Python for the Calamares Job class
+*
+* This is available as libcalamares.job in Python code.
+*/
+    class JobProxy
+    {
+    public:
+        explicit JobProxy( Calamares::Python::Job* parent );
+
+        std::string prettyName;
+        std::string workingPath;
+        std::string moduleName;
+
+        Dictionary configuration;
+
+        void setprogress( qreal progress );
+
+    private:
+        Calamares::Python::Job* m_parent;
+    };
+
+    class GlobalStorageProxy
+    {
+    public:
+        explicit GlobalStorageProxy( Calamares::GlobalStorage* gs );
+
+        bool contains( const std::string& key ) const;
+        int count() const;
+        void insert( const std::string& key, const Object& value );
+        List keys() const;
+        int remove( const std::string& key );
+        Object value( const std::string& key ) const;
+
+        // This is a helper for scripts that do not go through
+        // the JobQueue (i.e. the module testpython script),
+        // which allocate their own (singleton) GlobalStorage.
+        static Calamares::GlobalStorage* globalStorageInstance() { return s_gs_instance; }
+
+    private:
+        Calamares::GlobalStorage* m_gs;
+        static Calamares::GlobalStorage* s_gs_instance;  // See globalStorageInstance()
+    };
+
+
+}  // namespace )
+}  // namespace Calamares
+
+#endif

src/libcalamares/python/Logger.h

@@ -0,0 +1,36 @@
+/* === This file is part of Calamares - <https://calamares.io> ===
+ *
+ *   SPDX-FileCopyrightText: 2023 Adriaan de Groot <groot@kde.org>
+ *   SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ *   Calamares is Free Software: see the License-Identifier above.
+ *
+ *
+ */
+
+#ifndef CALAMARES_PYTHON_LOGGER_H
+#define CALAMARES_PYTHON_LOGGER_H
+
+/** @file
+ *
+ * Additional logging helpers for pybind11 types.
+ */
+
+#include "utils/Logger.h"
+
+#undef slots
+#include <pybind11/pybind11.h>
+
+#include <string>
+
+inline QDebug&
+operator<<( QDebug& s, const pybind11::handle& h )
+{
+#if QT_VERSION < QT_VERSION_CHECK( 6, 0, 0 )
+    return s << QString::fromUtf8( pybind11::str( h ).cast< std::string >().c_str() );
+#else
+    return s << pybind11::str( h ).cast< std::string >();
+#endif
+}
+
+#endif

src/libcalamares/python/Pybind11Helpers.h

@@ -0,0 +1,38 @@
+/* === This file is part of Calamares - <https://calamares.io> ===
+ *
+ *   SPDX-FileCopyrightText: 2023 Adriaan de Groot <groot@kde.org>
+ *   SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ *   Calamares is Free Software: see the License-Identifier above.
+ *
+ */
+
+#ifndef CALAMARES_PYTHON_PYBIND11_HELPERS_H
+#define CALAMARES_PYTHON_PYBIND11_HELPERS_H
+
+#include <QString>
+
+#include <string>
+
+#undef slots
+#include <pybind11/pybind11.h>
+
+namespace Calamares
+{
+namespace Python __attribute__( ( visibility( "hidden" ) ) )
+{
+    using Dictionary = pybind11::dict;
+    using String = pybind11::str;
+    using List = pybind11::list;
+    using Object = pybind11::object;
+
+    using Float = double;
+
+    inline QString asQString( const pybind11::handle& o )
+    {
+        return QString::fromUtf8( pybind11::str( o ).cast< std::string >().c_str() );
+    }
+
+}  // namespace )
+}  // namespace Calamares
+#endif

src/libcalamares/python/PythonJob.cpp

@@ -0,0 +1,261 @@
+/* === This file is part of Calamares - <https://calamares.io> ===
+ *
+ *   SPDX-FileCopyrightText: 2023 Adriaan de Groot <groot@kde.org>
+ *   SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ *   Calamares is Free Software: see the License-Identifier above.
+ *
+ */
+#include "python/PythonJob.h"
+
+#include "GlobalStorage.h"
+#include "JobQueue.h"
+#include "python/Api.h"
+#include "python/Logger.h"
+#include "utils/Logger.h"
+
+#include <QDir>
+#include <QFileInfo>
+#include <QString>
+
+#undef slots
+#include <pybind11/embed.h>
+#include <pybind11/eval.h>
+
+namespace py = pybind11;
+
+namespace
+{
+
+static const char* s_preScript = nullptr;
+
+QString
+getPrettyNameFromScope( const py::dict& scope )
+{
+    static constexpr char key_name[] = "pretty_name";
+
+    if ( scope.contains( key_name ) )
+    {
+        const py::object func = scope[ key_name ];
+        try
+        {
+            const auto s = func().cast< std::string >();
+            return QString::fromUtf8( s.c_str() );
+        }
+        catch ( const py::cast_error& e )
+        {
+            // Ignore, we will try __doc__ next
+        }
+    }
+
+    static constexpr char key_doc[] = "__doc__";
+    if ( scope.contains( key_doc ) )
+    {
+        const py::object doc = scope[ key_doc ];
+        try
+        {
+            const auto s = doc.cast< std::string >();
+            auto string = QString::fromUtf8( s.c_str() ).trimmed();
+            const auto newline_index = string.indexOf( '\n' );
+            if ( newline_index >= 0 )
+            {
+                string.truncate( newline_index );
+                return string;
+            }
+            // __doc__ is apparently empty, try next fallback
+        }
+        catch ( const py::cast_error& e )
+        {
+            // Ignore, try next fallback
+        }
+    }
+
+    // No more fallbacks
+    return QString();
+}
+
+}  // namespace
+
+namespace Calamares
+{
+namespace Python
+{
+
+struct Job::Private
+{
+    Private( const QString& script, const QString& path, const QVariantMap& configuration )
+        : scriptFile( script )
+        , workingPath( path )
+        , configurationMap( configuration )
+    {
+    }
+    QString scriptFile;  // From the module descriptor
+    QString workingPath;
+
+    QVariantMap configurationMap;  // The module configuration
+
+    QString description;  // Obtained from the Python code
+};
+
+Job::Job( const QString& scriptFile,
+          const QString& workingPath,
+          const QVariantMap& moduleConfiguration,
+          QObject* parent )
+    : m_d( std::make_unique< Job::Private >( scriptFile, workingPath, moduleConfiguration ) )
+{
+}
+
+Job::~Job() {}
+
+QString
+Job::prettyName() const
+{
+    return QDir( m_d->workingPath ).dirName();
+}
+
+QString
+Job::prettyStatusMessage() const
+{
+    // The description is updated when progress is reported, see emitProgress()
+    if ( m_d->description.isEmpty() )
+    {
+        return tr( "Running %1 operation." ).arg( prettyName() );
+    }
+    else
+    {
+        return m_d->description;
+    }
+}
+
+JobResult
+Job::exec()
+{
+    // We assume m_scriptFile to be relative to m_workingPath.
+    QDir workingDir( m_d->workingPath );
+    if ( !workingDir.exists() || !workingDir.isReadable() )
+    {
+        return JobResult::error( tr( "Bad working directory path" ),
+                                 tr( "Working directory %1 for python job %2 is not readable." )
+                                     .arg( m_d->workingPath )
+                                     .arg( prettyName() ) );
+    }
+
+    QFileInfo scriptFI( workingDir.absoluteFilePath( m_d->scriptFile ) );
+    if ( !scriptFI.exists() || !scriptFI.isFile() || !scriptFI.isReadable() )
+    {
+        return JobResult::error( tr( "Bad main script file" ),
+                                 tr( "Main script file %1 for python job %2 is not readable." )
+                                     .arg( scriptFI.absoluteFilePath() )
+                                     .arg( prettyName() ) );
+    }
+
+    py::scoped_interpreter guard {};
+    auto scope = py::module_::import( "__main__" ).attr( "__dict__" );
+    auto calamaresModule = py::module::import( "libcalamares" );
+    calamaresModule.attr( "job" ) = Calamares::Python::JobProxy( this );
+    calamaresModule.attr( "globalstorage" )
+        = Calamares::Python::GlobalStorageProxy( JobQueue::instance()->globalStorage() );
+
+    if ( s_preScript )
+    {
+        py::exec( s_preScript );
+    }
+    py::eval_file( scriptFI.absoluteFilePath().toUtf8().constData(), scope );
+
+    m_d->description = getPrettyNameFromScope( scope );
+
+    Q_EMIT progress( 0 );
+    static constexpr char key_run[] = "run";
+    if ( scope.contains( key_run ) )
+    {
+        const py::object run = scope[ key_run ];
+        try
+        {
+            py::object r;
+            try
+            {
+                r = run();
+            }
+            catch ( const py::error_already_set& e )
+            {
+                // This is an error in the Python code itself
+                cError() << e.what();
+                return JobResult::internalError( tr( "Bad main script file" ),
+                                                 tr( "Main script file %1 for python job %2 raised an exception." )
+                                                     .arg( scriptFI.absoluteFilePath() )
+                                                     .arg( prettyName() ),
+                                                 JobResult::PythonUncaughtException );
+            }
+
+            if ( r.is( py::none() ) )
+            {
+                return JobResult::ok();
+            }
+            const py::tuple items = r;
+            return JobResult::error( asQString( items[ 0 ] ), asQString( items[ 1 ] ) );
+        }
+        catch ( const py::cast_error& e )
+        {
+            cError() << e.what();
+            return JobResult::error( tr( "Bad main script file" ),
+                                     tr( "Main script file %1 for python job %2 returned invalid results." )
+                                         .arg( scriptFI.absoluteFilePath() )
+                                         .arg( prettyName() ) );
+        }
+        catch ( const py::error_already_set& e )
+        {
+            cError() << e.what();
+            return JobResult::error( tr( "Bad main script file" ),
+                                     tr( "Main script file %1 for python job %2 returned invalid results." )
+                                         .arg( scriptFI.absoluteFilePath() )
+                                         .arg( prettyName() ) );
+        }
+    }
+    else
+    {
+        return JobResult::error( tr( "Bad main script file" ),
+                                 tr( "Main script file %1 for python job %2 does not contain a run() function." )
+                                     .arg( scriptFI.absoluteFilePath() )
+                                     .arg( prettyName() ) );
+    }
+}
+
+QString
+Job::workingPath() const
+{
+    return m_d->workingPath;
+}
+QVariantMap
+Job::configuration() const
+{
+    return m_d->configurationMap;
+}
+
+void
+Job::emitProgress( double progressValue )
+{
+    // TODO: update prettyname
+    emit progress( progressValue );
+}
+
+/** @brief Sets the pre-run Python code for all PythonJobs
+ *
+ * A PythonJob runs the code from the scriptFile parameter to
+ * the constructor; the pre-run code is **also** run, before
+ * even the scriptFile code. Use this in testing mode
+ * to modify Python internals.
+ *
+ * No ownership of @p script is taken: pass in a pointer to
+ * a character literal or something that lives longer than the
+ * job. Pass in @c nullptr to switch off pre-run code.
+ */
+void
+Job::setInjectedPreScript( const char* script )
+{
+    s_preScript = script;
+    cDebug() << "Python pre-script set to string" << Logger::Pointer( script ) << "length"
+             << ( script ? strlen( script ) : 0 );
+}
+
+}  // namespace Python
+}  // namespace Calamares

src/libcalamares/python/PythonJob.h

@@ -0,0 +1,66 @@
+/* === This file is part of Calamares - <https://calamares.io> ===
+ *
+ *   SPDX-FileCopyrightText: 2023 Adriaan de Groot <groot@kde.org>
+ *   SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ *   Calamares is Free Software: see the License-Identifier above.
+ *
+ */
+
+#ifndef CALAMARES_PYTHON_PYTHONJOB_H
+#define CALAMARES_PYTHON_PYTHONJOB_H
+
+// This file is called PythonJob.h because it would otherwise
+// clashwith the Job.h in libcalamares proper.
+
+#include "Job.h"
+
+#include <QVariantMap>
+
+#include <memory>
+
+namespace Calamares
+{
+namespace Python
+{
+class Job : public ::Calamares::Job
+{
+    Q_OBJECT
+public:
+    explicit Job( const QString& scriptFile,
+                  const QString& workingPath,
+                  const QVariantMap& moduleConfiguration = QVariantMap(),
+                  QObject* parent = nullptr );
+    ~Job() override;
+
+    QString prettyName() const override;
+    QString prettyStatusMessage() const override;
+    ::Calamares::JobResult exec() override;
+
+    /** @brief Sets the pre-run Python code for all PythonJobs
+     *
+     * A PythonJob runs the code from the scriptFile parameter to
+     * the constructor; the pre-run code is **also** run, before
+     * even the scriptFile code. Use this in testing mode
+     * to modify Python internals.
+     *
+     * No ownership of @p script is taken: pass in a pointer to
+     * a character literal or something that lives longer than the
+     * job. Pass in @c nullptr to switch off pre-run code.
+     */
+    static void setInjectedPreScript( const char* script );
+
+    /** @brief Accessors for JobProxy */
+    QString workingPath() const;
+    QVariantMap configuration() const;
+    /** @brief Proxy functions */
+    void emitProgress( double progressValue );
+
+private:
+    struct Private;
+    std::unique_ptr< Private > m_d;
+};
+
+}  // namespace Python
+}  // namespace Calamares
+#endif

src/libcalamaresui/CMakeLists.txt

@@ -64,6 +64,10 @@ if(WITH_QML)
     target_link_libraries(calamaresui PUBLIC ${qtname}::QuickWidgets)
 endif()
 
+if(WITH_PYBIND11)
+    target_compile_definitions(calamaresui PRIVATE WITH_PYBIND11=1)
+endif()
+
 add_library(Calamares::calamaresui ALIAS calamaresui)
 
 ### Installation

src/libcalamaresui/modulesystem/PythonJobModule.cpp

@@ -1,6 +1,7 @@
 /* === This file is part of Calamares - <https://calamares.io> ===
  *
  *   SPDX-FileCopyrightText: 2014 Teo Mrnjavac <teo@kde.org>
+ *   SPDX-FileCopyrightText: 2023 Adriaan de Groot <groot@kde.org>
  *   SPDX-License-Identifier: GPL-3.0-or-later
  *
  *   Calamares is Free Software: see the License-Identifier above.
@@ -9,7 +10,14 @@
 
 #include "PythonJobModule.h"
 
+#if WITH_PYBIND11
+#include "python/PythonJob.h"
+using JobType = Calamares::Python::Job;
+#else
+// Old Boost::Python version
 #include "PythonJob.h"
+using JobType = Calamares::PythonJob;
+#endif
 
 #include <QDir>
 
@@ -40,7 +48,7 @@ PythonJobModule::loadSelf()
         return;
     }
 
-    m_job = Calamares::job_ptr( new PythonJob( m_scriptFileName, m_workingPath, m_configurationMap ) );
+    m_job = Calamares::job_ptr( new JobType( m_scriptFileName, m_workingPath, m_configurationMap ) );
     m_loaded = true;
 }
 

src/modules/README.md

@@ -334,7 +334,8 @@ description if something went wrong.
 The interface from a Python module to Calamares internals is
 found in the *libcalamares* module. This is not a standard Python
 module, and is only available inside the Calamares "runtime" for
-Python modules (it is implemented through Boost::Python in C++).
+Python modules (it is implemented in C++ and injected into the Python
+environment by Calamares).
 
 A module should start by importing the Calamares internals: