https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127592
--- Comment #1 from Philip Craig <philip at pobox dot com> --- Still reproduces with the 20261101 snapshot (a7a46d303ca5). Only -fsanitize=null, -fsanitize=alignment and -fsanitize=vptr trigger it. The other -fsanitize=undefined checks and -fsanitize=address accept the testcase, and -fsanitize=undefined -fno-sanitize=null,alignment,vptr compiles it. Declaring enum_to_string constexpr shows the sanitizer making it an immediate function. Without the flag it compiles and runs; with -fsanitize=null: error: call to consteval function 'enum_to_string<Suit>(Suit::Clubs)' is not a constant expression
