From 7b5ef2dfe9433c0d4d3580c855945e8b79d223eb Mon Sep 17 00:00:00 2001
From: Elliot Haisley <35050275+Apache-HB@users.noreply.github.com>
Date: Mon, 5 Apr 2021 10:14:26 -0400
Subject: [PATCH] use const_check

---
 include/fmt/core.h | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/include/fmt/core.h b/include/fmt/core.h
index 73a3b0d3..f1684657 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -98,13 +98,6 @@
 #  define FMT_CONSTEXPR_DECL
 #endif
 
-// C++17's char_traits::length() is constexpr.
-#if __cplusplus >= 201703L
-#  define FMT_CONSTEXPR_CHAR_TRAITS_LENGTH FMT_CONSTEXPR
-#else
-#  define FMT_CONSTEXPR_CHAR_TRAITS_LENGTH
-#endif
-
 #ifndef FMT_OVERRIDE
 #  if FMT_HAS_FEATURE(cxx_override_control) || \
       (FMT_GCC_VERSION >= 408 && FMT_HAS_GXX_CXX11) || FMT_MSC_VER >= 1900
@@ -399,8 +392,12 @@ template <typename Char> class basic_string_view {
     the size with ``std::char_traits<Char>::length``.
     \endrst
    */
-  FMT_CONSTEXPR_CHAR_TRAITS_LENGTH FMT_INLINE basic_string_view(const Char* s) : data_(s) {
-    if FMT_CONSTEXPR_CHAR_TRAITS_LENGTH (std::is_same<Char, char>::value && !detail::is_constant_evaluated())
+// C++17's char_traits::length() is constexpr.
+#if __cplusplus >= 201703L
+  constexpr
+#endif
+  FMT_INLINE basic_string_view(const Char* s) : data_(s) {
+    if (detail::const_check(std::is_same<Char, char>::value && !detail::is_constant_evaluated()))
       size_ = std::strlen(reinterpret_cast<const char*>(s));
     else
       size_ = std::char_traits<Char>::length(s);