Hi, If you got issues with using the Python C API <Python.h> in C++, please speak up! I'm looking for feedback :-)
Extending Python by writing C++ code is now easy with the pybind11 project: https://pybind11.readthedocs.io/ It seems like over the last years, building C++ extensions with the Python C API started to emit more C++ compiler warnings. One explanation may be that converting macros to static inline functions (PEP 670) introduce new warnings, even if the old and the new code is exactly the same. I just discover this issue recently. C and C++ compilers treat static inline functions differently. Macros are treated at legacy code which cannot be fixed, like system headers or old C header files, and so many warnings are made quiet. Static inline functions (defined in header files) are treated as regular code and compilers are more eager to emit warnings. I just modified the Python C API to use C++ static_cast<type>(expr) and reinterpret_cast<type>(expr) if it's used with C++. In C, the regular (type)expr cast (called "old-style cast" by C++ compilers ;-)) is still used as before. I'm also working on adding an unit test to make suite that using the Python C API works with a C++ compiler and doesn't emit compiler warnings: * https://github.com/python/cpython/issues/91321 * https://github.com/python/cpython/pull/32175 In terms of C++ version, it was proposed to target C++11. In the pythoncapi-compat project, I got warnings when the NULL constant is used in static inline functions. I modified the pythoncapi_compat.h header file to use nullptr if used with C++ to fix these compiler warnings. So far, I'm unable to reproduce the issue with <Python.h>, and so I didn't try to address this issue in Python. Victor -- Night gathers, and now my watch begins. It shall not end until my death. _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-le...@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/73UTO4MTKVJR7XWXTHLOV3V2L2QKP2TK/ Code of Conduct: http://python.org/psf/codeofconduct/
