[Bug libstdc++/107901] std::format isn't usable on 16-bit targets

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107901

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Or simply:

--- a/libstdc++-v3/include/std/format
+++ b/libstdc++-v3/include/std/format
@@ -3034,6 +3034,7 @@ namespace __format
              return std::forward<_Visitor>(__vis)(_M_val._M_ll);
            case _Arg_ull:
              return std::forward<_Visitor>(__vis)(_M_val._M_ull);
+#if __cpp_lib_to_chars
            case _Arg_flt:
              return std::forward<_Visitor>(__vis)(_M_val._M_flt);
            case _Arg_dbl:
@@ -3046,6 +3047,7 @@ namespace __format
              return std::forward<_Visitor>(__vis)(_M_val._M_f128);
            case _Arg_ibm128:
              return std::forward<_Visitor>(__vis)(_M_val._M_ibm128);
+#endif
 #endif
            case _Arg_str:
              return std::forward<_Visitor>(__vis)(_M_val._M_str);