[gcc r11-9960] [PR105324] libstdc++: testsuite: pr105324 requires FP from_char

[gcc r11-9960] [PR105324] libstdc++: testsuite: pr105324 requires FP from_char

[Alexandre Oliva]

https://gcc.gnu.org/g:799ff8e3e38f62632a98f8931ca291d191e677d5

commit r11-9960-g799ff8e3e38f62632a98f8931ca291d191e677d5
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Fri May 6 07:33:50 2022 -0300

    [PR105324] libstdc++: testsuite: pr105324 requires FP from_char
    
    The floating-point overloads of from_char are only declared if
    _GLIBCXX_HAVE_USELOCALE is #defined as nonzero.  That's exposed from
    charconv as __cpp_lib_to_chars >= 201611L, so guard the test body with
    that.
    
    
    for  libstdc++-v3/ChangeLog
    
            PR c++/105324
            * testsuite/20_util/from_chars/pr105324.cc: Guard test body
            with conditional for floating-point overloads of from_char.
    
    (cherry picked from commit 25389f3de489c25a6983db96428a6bf06aedc829)

Diff:
---
 libstdc++-v3/testsuite/20_util/from_chars/pr105324.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libstdc++-v3/testsuite/20_util/from_chars/pr105324.cc b/libstdc++-v3/testsuite/20_util/from_chars/pr105324.cc
index cecb17e41cc..ef24b4c5c7b 100644
--- a/libstdc++-v3/testsuite/20_util/from_chars/pr105324.cc
+++ b/libstdc++-v3/testsuite/20_util/from_chars/pr105324.cc
@@ -5,10 +5,12 @@
 
 int main()
 {
+#if __cpp_lib_to_chars >= 201611L // FP from_char not available otherwise.
   // PR libstdc++/105324
   // std::from_chars() assertion at floating_from_chars.cc:78
   std::string s(512, '1');
   s[1] = '.';
   long double d;
   std::from_chars(s.data(), s.data() + s.size(), d);
+#endif
 }