https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93745
--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> --- That's why I asked "What language relies on this?" But regardless of what language might have even looser rules than C/C++ in this area, it would seem like a rather unfortunate design limitation for GCC not to be able to analyze and optimize C/C++ code as well as other compilers can because it supports languages others don't (LLVM supports most of the languages GCC does). What would it take to get GCC to handle this case? Changing the front-end to implicitly declare p restrict? (That would only work in a small subset of cases and would be wrong in many more.)