https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71125
--- Comment #2 from Casey Carter <Casey at Carter dot net> --- (In reply to Jonathan Wakely from comment #1) > Is this valid in C++20? Definitely not: there are no concept functions in C++20. > > I think G++ is correct to reject it due to redeclaring C1, C2 etc. as a > different kind of symbol. I agree. Only functions and function templates may be overloaded, and despite appearances to the contrary a function concept declaration declares a concept, not a function template. I suggest classifying this as a poor diagnostic for TS concepts.
