From cac99da8dc88be719a728dc1b597b0ac307c1800 Mon Sep 17 00:00:00 2001
From: Howard Hinnant <howard.hinnant@gmail.com>
Date: Tue, 2 Jun 2020 21:08:57 -0400
Subject: [PATCH] For traits in constexpr context use ::value

* Fixes #542
---
 include/date/date.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/date/date.h b/include/date/date.h
index 3d9d7768..7e8aa9e8 100644
--- a/include/date/date.h
+++ b/include/date/date.h
@@ -4148,10 +4148,10 @@ operator+(std::basic_string<CharT, Traits, Alloc> x, const string_literal<CharT,
                            && (!defined(__SUNPRO_CC) || __SUNPRO_CC > 0x5150)
 
 template <class CharT,
-          class = std::enable_if_t<std::is_same<CharT, char>{} ||
-                                   std::is_same<CharT, wchar_t>{} ||
-                                   std::is_same<CharT, char16_t>{} ||
-                                   std::is_same<CharT, char32_t>{}>>
+          class = std::enable_if_t<std::is_same<CharT, char>::value ||
+                                   std::is_same<CharT, wchar_t>::value ||
+                                   std::is_same<CharT, char16_t>::value ||
+                                   std::is_same<CharT, char32_t>::value>>
 CONSTCD14
 inline
 string_literal<CharT, 2>