[docs] [issue17589] Make documentation about macros in C API explicit about rvalue vs statement

Antoine Pitrou added the comment: Py_INCREF usable as an rvalue sounds more like an accident than a deliberate feature, and it would be IMO counter-productive to codify this behaviour in the docs. As for the lvalue usage of Py_REFCNT and Py_SIZE, I think it would be better if it were limited to CPython core. But arguably writers of extension types may want to mutate the size field of a varsize object. ---------- nosy: +pitrou _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17589> _______________________________________