libstdc++: Remove unused local type alias <format>.

After r16-4421-g59cabe08b57a26 the local type alias _String isn't used
anymore and therefore causes warnings when building the tests with
`-Wall -Wextra`.

libstdc++-v3/ChangeLog:

	* include/std/format (_M_format_range): Remove unused local type
	alias _String.

Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>0
Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>

diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format
index 8ba6af6bd4058c18d432b78735565dec5219e8ca..1102ac8f6e8ab7be23a9905d49bebf0ff59ab6b1 100644 (file)
--- a/libstdc++-v3/include/std/format
+++ b/libstdc++-v3/include/std/format
@@ -1426,7 +1426,6 @@ namespace __format
        _M_format_range(_Rg&& __rg, basic_format_context<_Out, _CharT>& __fc) const
        {
          using _Range = remove_reference_t<_Rg>;
-         using _String = basic_string<_CharT>;
          using _String_view = basic_string_view<_CharT>;
          if constexpr (!is_lvalue_reference_v<_Rg>)
            return _M_format_range<_Range&>(__rg, __fc);