[Bug libstdc++/110860] std::format("{:f}",2e304) invokes undefined behaviour

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110860

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
__builtin_log10 isn't generic either. I was hoping to avoid including all of
<cmath> here, which is why I used the built-ins.