Hi Antoine, I'm in favor of making the C API more strict. The limited C API of Python 3.11 no longer cast arguments to PyObject* ! The caller must now cast to PyObject*: see PEP 670 "convert macros to functions".
Converting macros to static inline functions (PEP 670) is already an important change. I prefer to not change too many things at the same time. Maybe in Python 3.12 (or later), we can consider requiring to not pass "const PyObject*" in C++: remove the cast dropping constness of the argument. My long term goal is to only use opaque "PyObject*" "handles" in the C API. But for practical reasons, changing the C API must be done slowly, step by step. To reduce the maintenance burden in third party C and C+ extensions. -- IMO it's a bad idea to use "const PyObject*" in the C API. Maybe today, a function doesn't modify the memory. But maybe tomorrow, the implementation will deeply change and will need to modify the memory. In C, using "const" (for something other than const char*) is just not convenient. Victor On Tue, May 3, 2022 at 9:22 AM Antoine Pitrou <anto...@python.org> wrote: > On Mon, 2 May 2022 15:21:24 +0200 > Victor Stinner <vstin...@python.org> wrote: > > > > Slowly, more and more tests can be added. For example, this change fixing > > compiler warnings when passing "const PyObject*" to Python C API > functions > > adds tests to _testcppext.cpp: > > https://github.com/python/cpython/pull/92138 > > Doesn't passing "const PyObject*" leak implementation details, for > example that the reference count does not change? It seems to go > counter the objective of making the C API more abstract and more stable. > > (C++ has the "mutable" keyword for such situat but I don't think C has > it yet) > > Regards > > Antoine. > > > _______________________________________________ > 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/YFD3WOOR6PRORTTKLTSSOSDNHRYAA2N7/ > Code of Conduct: http://python.org/psf/codeofconduct/ > -- Night gathers, and now my watch begins. It shall not end until my death.
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