https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65455
--- Comment #5 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- stdatomic.h uses both __auto_type and __typeof__. In the cases where __typeof__ is used, (a) const and _Atomic (and maybe volatile) must be removed and (b) __auto_type would not be correct (the type in question is not the type of the initializer, and if the types are different then the conversions from the type of the initializer to the type given with __typeof__ are required). The dropping of qualifiers only when _Atomic was present was the conservative minimal change that could not affect any existing code using typeof. It may well be that __typeof__ should always treat its argument as being an rvalue and so as having no qualifiers, but it wasn't necessary to resolve that issue at that time. __auto_type and __typeof__ should be consistent with each other to avoid making the language even more confusing.
