[Bug libstdc++/110653] Support std::stoi etc. without C99 APIs

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110653

--- Comment #10 from Jonathan Wakely <redi at gcc dot gnu.org> ---
And this should fix it:

--- a/libstdc++-v3/include/c_global/cstdlib
+++ b/libstdc++-v3/include/c_global/cstdlib
@@ -256,6 +256,20 @@ namespace std
   using ::__gnu_cxx::strtold;
 } // namespace std

+#else  // ! _GLIBCXX_USE_C99_STDLIB
+
+// We also check for strtof and strtold separately from
_GLIBCXX_USE_C99_STDLIB
+
+#if _GLIBCXX_HAVE_STRTOF
+#undef strtof
+namespace std { using ::strtof; }
+#endif
+
+#if _GLIBCXX_HAVE_STRTOLD
+#undef strtold
+namespace std { using ::strtold; }
+#endif
+
 #endif // _GLIBCXX_USE_C99_STDLIB

 } // extern "C++"