mirror of
https://github.com/pybind/pybind11.git
synced 2026-03-14 20:27:47 +00:00
74b5242713
* Added weak_ptr test (currently failing)
* Cleanup
* [skip ci] Simplify test case.
* Add test_class_sp_trampoline_weak_ptr.cpp,py (using std::shared_ptr as holder). Tweak test_class_sh_trampoline_weak_ptr.py to pass, with `# THIS NEEDS FIXING` comment.
* Resolve clang-tidy errors
```
/__w/pybind11/pybind11/tests/test_class_sh_trampoline_weak_ptr.cpp:23:43: error: the parameter 'sp' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param,-warnings-as-errors]
23 | void set_wp(std::shared_ptr<VirtBase> sp) { wp = sp; }
| ^
| const &
4443 warnings generated.
```
```
/__w/pybind11/pybind11/tests/test_class_sp_trampoline_weak_ptr.cpp:23:43: error: the parameter 'sp' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param,-warnings-as-errors]
23 | void set_wp(std::shared_ptr<VirtBase> sp) { wp = sp; }
| ^
| const &
4430 warnings generated.
```
* PYPY, GRAALPY: skip last part of test_weak_ptr_base
* Rename test_weak_ptr_base → test_weak_ptr_owner
* Add SpOwner, test_with_sp_owner, test_with_sp_and_wp_owners
* Modify py::trampoline_self_life_support semantics: if trampoline class does not inherit from this class, preserve established Inheritance Slicing behavior.
rwgk reached this point with the help of ChatGPT:
* https://chatgpt.com/share/68056498-7d94-8008-8ff0-232e2aba451c
The only production code change in this commit is:
```
diff --git a/include/pybind11/detail/type_caster_base.h b/include/pybind11/detail/type_caster_base.h
index d4f9a41e..f3d45301 100644
--- a/include/pybind11/detail/type_caster_base.h
+++ b/include/pybind11/detail/type_caster_base.h
@@ -776,6 +776,14 @@ struct load_helper : value_and_holder_helper {
if (released_ptr) {
return std::shared_ptr<T>(released_ptr, type_raw_ptr);
}
+ auto *self_life_support
+ = dynamic_raw_ptr_cast_if_possible<trampoline_self_life_support>(type_raw_ptr);
+ if (self_life_support == nullptr) {
+ std::shared_ptr<void> void_shd_ptr = hld.template as_shared_ptr<void>();
+ std::shared_ptr<T> to_be_released(void_shd_ptr, type_raw_ptr);
+ vptr_gd_ptr->released_ptr = to_be_released;
+ return to_be_released;
+ }
std::shared_ptr<T> to_be_released(
type_raw_ptr, shared_ptr_trampoline_self_life_support(loaded_v_h.inst));
vptr_gd_ptr->released_ptr = to_be_released;
```
* Remove debug printf in include/pybind11/pybind11.h
* Resolve MSVC error
```
11>D:\a\pybind11\pybind11\tests\test_class_sp_trampoline_weak_ptr.cpp(44,50): error C2220: the following warning is treated as an error [D:\a\pybind11\pybind11\build\tests\pybind11_tests.vcxproj]
11>D:\a\pybind11\pybind11\tests\test_class_sp_trampoline_weak_ptr.cpp(44,50): warning C4458: declaration of 'sp' hides class member [D:\a\pybind11\pybind11\build\tests\pybind11_tests.vcxproj]
D:\a\pybind11\pybind11\tests\test_class_sp_trampoline_weak_ptr.cpp(54,31):
see declaration of 'pybind11_tests::class_sp_trampoline_weak_ptr::SpOwner::sp'
```
* [skip ci] Undo the production code change under 4638e017b6
Also undo the corresponding test change in test_class_sh_trampoline_weak_ptr.py
But keep all extra debugging code for now.
* [skip ci] Introduce lambda in `WpOwner::set_wp` bindings, but simply cast to `std::shared_ptr<VirtBase>` for now.
* Add `py::potentially_slicing_shared_ptr()`
* Add `type_id<T>()` to `py::potentially_slicing_shared_ptr()` error message and add test.
* test_potentially_slicing_shared_ptr.cpp,py (for smart_holder only)
* Generalize test_potentially_slicing_shared_ptr.cpp,py for testing with smart_holder and std::shared_ptr as holder.
* Add back test_potentially_slicing_shared_ptr_not_convertible_error(), it got lost accidentally in commit 56d23dc478
* Add simple trampoline state assertions.
* Resolve clang-tidy errors.
```
/__w/pybind11/pybind11/tests/test_potentially_slicing_shared_ptr.cpp:30:9: error: 'magic_token' should be initialized in a member initializer of the constructor [cppcoreguidelines-prefer-member-initializer,-warnings-as-errors]
29 | trampoline_is_alive_simple(const trampoline_is_alive_simple &other) {
| : magic_token(other.magic_token)
30 | magic_token = other.magic_token;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/__w/pybind11/pybind11/tests/test_potentially_slicing_shared_ptr.cpp:33:9: error: 'magic_token' should be initialized in a member initializer of the constructor [cppcoreguidelines-prefer-member-initializer,-warnings-as-errors]
32 | trampoline_is_alive_simple(trampoline_is_alive_simple &&other) noexcept {
| : magic_token(other.magic_token)
33 | magic_token = other.magic_token;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
* Add a (long) C++ comment for py::potentially_slicing_shared_ptr<>()
* [skip ci] Add new "Avoiding Inheritance Slicing and ``std::weak_ptr`` surprises" section in advanced/classes.rst
* [skip ci] Add introductory comment to test_potentially_slicing_shared_ptr.py
* Minimal (!) changes to have py::potentially_slicing_weak_ptr<T>(handle) as the public API. For CI testing, before changing the names around more widely, and the documentation.
* Rename test_potentially_slicing_shared_ptr.cpp,py → test_potentially_slicing_weak_ptr.cpp,py
* Update docs/advanced/classes.rst and C++ comments → potentially_slicing_weak_ptr
* Write "shared_ptr" instead of just "pointer" in a couple places in docs/advanced/classes.rst
* Add comment for force_potentially_slicing_shared_ptr in type_caster_base.h, to make a direct connection py::potentially_slicing_weak_ptr
---------
Co-authored-by: Ralf W. Grosse-Kunstleve <rgrossekunst@nvidia.com>
.. figure:: https://github.com/pybind/pybind11/raw/master/docs/pybind11-logo.png
:alt: pybind11 logo
**pybind11 (v3) — Seamless interoperability between C++ 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 (CPython 3.8+, PyPy, or GraalPy) and the C++
standard library. This compact implementation was possible thanks to some 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
- Integrated NumPy support (NumPy 2 requires pybind11 2.12+)
Goodies
-------
In addition to the core functionality, pybind11 provides some extra
goodies:
- Python 3.8+, PyPy3 7.3.17+, and GraalPy 24.1+ 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,
Dustin Spicuzza,
Boris Staletic,
Ethan Steinberg,
Patrick Stewart,
Ivor Wanders,
and
Xiaofei Wang.
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