https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95700
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #1) > I don't think it is a good idea to allow (uintptr_t) 0 as valid sentinel. Definitely not. (uintptr_t)0 is not a null pointer constant, and is not a valid definition of NULL for C++.