https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104392
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- clang rejects this too: <source>:9:12: error: argument to 'operator<=>' cannot be narrowed from type 'unsigned int' to 'int' return left.a <=> right.a; ^ <source>:9:23: error: argument to 'operator<=>' cannot be narrowed from type 'unsigned int' to 'int' return left.a <=> right.a; ^