Vendor import of libc++ release_40 branch r292009:vendor/libc++/libc++-release_40-r292009

https://llvm.org/svn/llvm-project/libcxx/branches/release_40@292009

1 files changed, 15 insertions, 0 deletions

diff --git a/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char16_t/compare.pass.cpp b/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char16_t/compare.pass.cpp
index 7356097a6677..b4be1402ad1c 100644
--- a/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char16_t/compare.pass.cpp
+++ b/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char16_t/compare.pass.cpp
@@ -12,12 +12,23 @@
 // template<> struct char_traits<char16_t>
 
 // static int compare(const char_type* s1, const char_type* s2, size_t n);
+// constexpr in C++17
 
 #include <string>
 #include <cassert>
 
 #include "test_macros.h"
 
+#if TEST_STD_VER > 14
+constexpr bool test_constexpr()
+{
+    return std::char_traits<char16_t>::compare(u"123", u"223", 3) < 0
+        && std::char_traits<char16_t>::compare(u"223", u"123", 3) > 0
+        && std::char_traits<char16_t>::compare(u"123", u"123", 3) == 0;
+}
+#endif
+
+
 int main()
 {
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
@@ -43,5 +54,9 @@ int main()
     assert(std::char_traits<char16_t>::compare(u"133", u"123", 3) > 0);
     assert(std::char_traits<char16_t>::compare(u"124", u"123", 3) > 0);
 #endif
+
+#if TEST_STD_VER > 14
+    static_assert(test_constexpr(), "" );
+#endif
 #endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
 }