[Bug c++/116696] function template not considered constexpr even with -fimplicit-constexpr

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116696

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Created attachment 59104
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=59104&action=edit
slightly modified std::format implementation

This is the code from the compiler explorer link.

Compile with -std=c++23 -fimplicit-constexpr to see the error, add -DFIX to add
'constexpr' to that one function.