https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113500
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #6) > (In reply to Hirthammer from comment #5) > > This whole thing with std::format and std::chrono::time_point is currently a > > total minefield. > > That seems like an exaggeration. > > > In MSVC it is even more complicated and I already reported > > the bug in October 2023. See: > > > > https://developercommunity.visualstudio.com/t/Using-std::format-with- > > unsigned-integer-/10501153 > > > > If you change the clock to utc_clock or gps_clock the code compiles with > > MSVC (but not with GCC) on Compiler Explorer. > > It compiles fine with GCC for me. Ah, maybe you mean your original example. The one at in the MSVC bug report compiles fine with GCC using utc_clock and gps_clock. Your original example doesn't, because formatting a utc_time or gps_time is specified in terms of a sys_time, and that's how libstdc++ implements it. So if the utc_time or gps_time uses a float rep, we're back to square one. I'll ask the committee to clarify that too.
