https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90784
--- Comment #2 from ensadc at mailnesia dot com --- But curiously, gcc does replace the loop with the constant if `#undef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED` is added before `#include <string>`: https://godbolt.org/z/mVdLVP . (Why) is `__builtin_is_constant_evaluated` pessimizing?
