From 5726b70bb7a6dffed542101a54e634b4abab3663 Mon Sep 17 00:00:00 2001
From: Howard Hinnant <howard.hinnant@gmail.com>
Date: Mon, 24 Jul 2017 08:26:37 -0400
Subject: [PATCH] Turn off constexpr when using clang + VS-2013 std::lib

---
 date.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/date.h b/date.h
index 5876bed..c753b29 100644
--- a/date.h
+++ b/date.h
@@ -69,7 +69,7 @@ namespace date
 // Configuration |
 //---------------+
 
-#if defined(_MSC_VER) && !defined(__clang__)
+#if defined(_MSC_VER) && (!defined(__clang__) || (_MSC_VER < 1910))
 // MSVC
 #  if _MSC_VER < 1910
 //   before VS2017