[Bug libstdc++/96850] format missing from std

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96850

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Yes, as documented.

And also stated at https://en.cppreference.com/w/cpp/compiler_support