[gcc r16-8407] libstdc++: Check right value of __cpp_lib_format for dynamic_string

[Jonathan Wakely]

https://gcc.gnu.org/g:4886afeb5c35e323714d4763f20858ee94edce8c

commit r16-8407-g4886afeb5c35e323714d4763f20858ee94edce8c
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Apr 1 15:25:14 2026 +0100

    libstdc++: Check right value of __cpp_lib_format for dynamic_string
    
    This doesn't matter in practice, but strictly speaking the right value
    for defining std::dynamic_format is 202603 not 202311 (which was the
    macro value for the old name, std::runtime_format).
    
    libstdc++-v3/ChangeLog:
    
            * include/std/format (dynamic_format): Check new value for
            feature test macro.
    
    Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>

Diff:
---
 libstdc++-v3/include/std/format | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format
index 2bcd06822b75..eca5bd213aa0 100644
--- a/libstdc++-v3/include/std/format
+++ b/libstdc++-v3/include/std/format
@@ -195,7 +195,7 @@ namespace __format
       = basic_format_string<wchar_t, type_identity_t<_Args>...>;
 #endif
 
-#if __cpp_lib_format >= 202311L // >= C++26
+#if __cpp_lib_format >= 202603L // >= C++26
   [[__gnu__::__always_inline__]]
   inline __format::_Dynamic_format_string<char>
   dynamic_format(string_view __fmt) noexcept