Hi, Since Erlend and me posted PEP 670 on python-dev last October, we took all feedback (python-dev and Steering Council) in account to clarify the intent of the PEP and to reduce its scope (remove *any* risk of backward compatibility). PEP 670: https://python.github.io/peps/pep-0670/ Changes since the first version: * Stricter policy on not changing argument types and return type. * Better explain why pointer arguments require a cast to not emit new compiler warnings. * Macros which can be used as l-values are no longer modified by the PEP (I wrote PEP 674 just for that). * Macros having multiple return types are no longer modified by the PEP. * Limited C API version 3.11 no longer casts pointer arguments (move towards a cleaner API, but only if you opt in for that!). * No longer remove return values of macros "which should not have a return value" (this rule was complicated and in fact, all macros have already been fixed). * Add "Macros converted to functions since Python 3.8" section to show that macros already converted didn't introduce performance issue nor new compiler warnings. * Add "Benchmark comparing macros and static inline functions" section to prove that there is no significant impact on performance. Note: we already submitted PEP 670 to the Steering Council at the end of November, and the SC 2022 came with feedback, so we modified the PEP: https://mail.python.org/archives/list/python-dev@python.org/message/IJ3IBVY3... Following the SC decision, we already modified PEP 7 to add: "static inline functions should be preferred over macros in new code." https://www.python.org/dev/peps/pep-0007/#c-dialect Victor -- Night gathers, and now my watch begins. It shall not end until my death.