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* Adding initial README_smart_holder.rst. * Adding README_smart_holder.rst to MANIFEST.in and test_files.py.
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197 lines
8.0 KiB
ReStructuredText
.. figure:: https://github.com/pybind/pybind11/raw/master/docs/pybind11-logo.png
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:alt: pybind11 logo
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**pybind11 — Seamless operability between C++11 and Python**
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|Latest Documentation Status| |Stable Documentation Status| |Gitter chat| |CI| |Build status|
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|Repology| |PyPI package| |Conda-forge| |Python Versions|
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`Setuptools example <https://github.com/pybind/python_example>`_
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• `Scikit-build example <https://github.com/pybind/scikit_build_example>`_
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• `CMake example <https://github.com/pybind/cmake_example>`_
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.. start
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.. Note::
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This is the pybind11 **smart_holder** branch. Please refer to
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``README_smart_holder.rst`` for branch-specific information.
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.. warning::
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Combining older versions of pybind11 (< 2.6.0) with Python 3.9.0 will
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trigger undefined behavior that typically manifests as crashes during
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interpreter shutdown (but could also destroy your data. **You have been
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warned.**)
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We recommend that you update to the latest patch release of Python (3.9.1),
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which includes a `fix <https://github.com/python/cpython/pull/22670>`_
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that resolves this problem. If you do use Python 3.9.0, please update to
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the latest version of pybind11 (2.6.0 or newer), which includes a temporary
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workaround specifically when Python 3.9.0 is detected at runtime.
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**pybind11** is a lightweight header-only library that exposes C++ types
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in Python and vice versa, mainly to create Python bindings of existing
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C++ code. Its goals and syntax are similar to the excellent
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`Boost.Python <http://www.boost.org/doc/libs/1_58_0/libs/python/doc/>`_
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library by David Abrahams: to minimize boilerplate code in traditional
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extension modules by inferring type information using compile-time
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introspection.
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The main issue with Boost.Python—and the reason for creating such a
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similar project—is Boost. Boost is an enormously large and complex suite
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of utility libraries that works with almost every C++ compiler in
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existence. This compatibility has its cost: arcane template tricks and
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workarounds are necessary to support the oldest and buggiest of compiler
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specimens. Now that C++11-compatible compilers are widely available,
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this heavy machinery has become an excessively large and unnecessary
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dependency.
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Think of this library as a tiny self-contained version of Boost.Python
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with everything stripped away that isn’t relevant for binding
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generation. Without comments, the core header files only require ~4K
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lines of code and depend on Python (2.7 or 3.5+, or PyPy) and the C++
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standard library. This compact implementation was possible thanks to
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some of the new C++11 language features (specifically: tuples, lambda
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functions and variadic templates). Since its creation, this library has
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grown beyond Boost.Python in many ways, leading to dramatically simpler
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binding code in many common situations.
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Tutorial and reference documentation is provided at
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`pybind11.readthedocs.io <https://pybind11.readthedocs.io/en/latest>`_.
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A PDF version of the manual is available
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`here <https://pybind11.readthedocs.io/_/downloads/en/latest/pdf/>`_.
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And the source code is always available at
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`github.com/pybind/pybind11 <https://github.com/pybind/pybind11>`_.
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Core features
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-------------
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pybind11 can map the following core C++ features to Python:
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- Functions accepting and returning custom data structures per value,
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reference, or pointer
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- Instance methods and static methods
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- Overloaded functions
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- Instance attributes and static attributes
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- Arbitrary exception types
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- Enumerations
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- Callbacks
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- Iterators and ranges
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- Custom operators
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- Single and multiple inheritance
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- STL data structures
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- Smart pointers with reference counting like ``std::shared_ptr``
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- Internal references with correct reference counting
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- C++ classes with virtual (and pure virtual) methods can be extended
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in Python
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Goodies
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-------
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In addition to the core functionality, pybind11 provides some extra
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goodies:
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- Python 2.7, 3.5+, and PyPy/PyPy3 7.3 are supported with an
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implementation-agnostic interface.
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- It is possible to bind C++11 lambda functions with captured
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variables. The lambda capture data is stored inside the resulting
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Python function object.
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- pybind11 uses C++11 move constructors and move assignment operators
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whenever possible to efficiently transfer custom data types.
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- It’s easy to expose the internal storage of custom data types through
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Pythons’ buffer protocols. This is handy e.g. for fast conversion
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between C++ matrix classes like Eigen and NumPy without expensive
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copy operations.
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- pybind11 can automatically vectorize functions so that they are
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transparently applied to all entries of one or more NumPy array
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arguments.
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- Python’s slice-based access and assignment operations can be
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supported with just a few lines of code.
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- Everything is contained in just a few header files; there is no need
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to link against any additional libraries.
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- Binaries are generally smaller by a factor of at least 2 compared to
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equivalent bindings generated by Boost.Python. A recent pybind11
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conversion of PyRosetta, an enormous Boost.Python binding project,
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`reported <http://graylab.jhu.edu/RosettaCon2016/PyRosetta-4.pdf>`_
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a binary size reduction of **5.4x** and compile time reduction by
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**5.8x**.
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- Function signatures are precomputed at compile time (using
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``constexpr``), leading to smaller binaries.
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- With little extra effort, C++ types can be pickled and unpickled
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similar to regular Python objects.
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Supported compilers
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-------------------
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1. Clang/LLVM 3.3 or newer (for Apple Xcode’s clang, this is 5.0.0 or
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newer)
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2. GCC 4.8 or newer
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3. Microsoft Visual Studio 2015 Update 3 or newer
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4. Intel classic C++ compiler 18 or newer (ICC 20.2 tested in CI)
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5. Cygwin/GCC (previously tested on 2.5.1)
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6. NVCC (CUDA 11.0 tested in CI)
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7. NVIDIA PGI (20.9 tested in CI)
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About
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-----
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This project was created by `Wenzel
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Jakob <http://rgl.epfl.ch/people/wjakob>`_. Significant features and/or
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improvements to the code were contributed by Jonas Adler, Lori A. Burns,
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Sylvain Corlay, Eric Cousineau, Ralf Grosse-Kunstleve, Trent Houliston, Axel
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Huebl, @hulucc, Yannick Jadoul, Sergey Lyskov Johan Mabille, Tomasz Miąsko,
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Dean Moldovan, Ben Pritchard, Jason Rhinelander, Boris Schäling, Pim
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Schellart, Henry Schreiner, Ivan Smirnov, Boris Staletic, and Patrick Stewart.
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We thank Google for a generous financial contribution to the continuous
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integration infrastructure used by this project.
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Contributing
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~~~~~~~~~~~~
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See the `contributing
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guide <https://github.com/pybind/pybind11/blob/master/.github/CONTRIBUTING.md>`_
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for information on building and contributing to pybind11.
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License
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~~~~~~~
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pybind11 is provided under a BSD-style license that can be found in the
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`LICENSE <https://github.com/pybind/pybind11/blob/master/LICENSE>`_
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file. By using, distributing, or contributing to this project, you agree
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to the terms and conditions of this license.
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.. |Latest Documentation Status| image:: https://readthedocs.org/projects/pybind11/badge?version=latest
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:target: http://pybind11.readthedocs.org/en/latest
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.. |Stable Documentation Status| image:: https://img.shields.io/badge/docs-stable-blue.svg
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:target: http://pybind11.readthedocs.org/en/stable
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.. |Gitter chat| image:: https://img.shields.io/gitter/room/gitterHQ/gitter.svg
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:target: https://gitter.im/pybind/Lobby
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.. |CI| image:: https://github.com/pybind/pybind11/workflows/CI/badge.svg
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:target: https://github.com/pybind/pybind11/actions
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.. |Build status| image:: https://ci.appveyor.com/api/projects/status/riaj54pn4h08xy40?svg=true
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:target: https://ci.appveyor.com/project/wjakob/pybind11
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.. |PyPI package| image:: https://img.shields.io/pypi/v/pybind11.svg
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:target: https://pypi.org/project/pybind11/
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.. |Conda-forge| image:: https://img.shields.io/conda/vn/conda-forge/pybind11.svg
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:target: https://github.com/conda-forge/pybind11-feedstock
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.. |Repology| image:: https://repology.org/badge/latest-versions/python:pybind11.svg
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:target: https://repology.org/project/python:pybind11/versions
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.. |Python Versions| image:: https://img.shields.io/pypi/pyversions/pybind11.svg
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:target: https://pypi.org/project/pybind11/
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