[Bug c++/120917] warning: use of 'auto' in template argument only available with '-fconcepts-ts'

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120917

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Hmm, except that -pedantic never warned about that for C++20 and C++23 modes.