https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108391
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |MOVED Status|UNCONFIRMED |RESOLVED --- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to jinci kang from comment #3) > So what do you think I should do? > ```cpp > #ifdef __clang__ > #define __cpp_sized_deallocation > #endif No, don't do that! That has undefined behaviour. > I think this is a bit troublesome, this API can be used directly after C++14. Well like I said, it's a clang bug. The C++ standard requires the macro to be defined, but if Clang doesn't do that, the library won't declare the corresponding API. You should report this to Clang, not here.