From 4832ea0ddb844ee9752bde42a6ce1441bc5ae09e Mon Sep 17 00:00:00 2001
From: Howard Hinnant <howard.hinnant@gmail.com>
Date: Fri, 17 Nov 2017 11:08:39 -0500
Subject: [PATCH] Move HAS_STRING_VIEW to date.h

---
 include/date/date.h | 12 +++++++++++-
 include/date/tz.h   |  8 --------
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/include/date/date.h b/include/date/date.h
index 1bad46d..c97936d 100644
--- a/include/date/date.h
+++ b/include/date/date.h
@@ -30,8 +30,15 @@
 // been invented (that would involve another several millennia of evolution).
 // We did not mean to shout.
 
-#include <cassert>
+#ifndef HAS_STRING_VIEW
+#  if __cplusplus >= 201703
+#    define HAS_STRING_VIEW 1
+#  else
+#    define HAS_STRING_VIEW 0
+#  endif
+#endif  // HAS_STRING_VIEW
 
+#include <cassert>
 #include <algorithm>
 #include <cctype>
 #include <chrono>
@@ -53,6 +60,9 @@
 #include <sstream>
 #include <stdexcept>
 #include <string>
+#if HAS_STRING_VIEW
+# include <string_view>
+#endif
 #include <utility>
 #include <type_traits>
 
diff --git a/include/date/tz.h b/include/date/tz.h
index d85d6f9..532fe69 100644
--- a/include/date/tz.h
+++ b/include/date/tz.h
@@ -104,14 +104,6 @@ static_assert(HAS_REMOTE_API == 0 ? AUTO_DOWNLOAD == 0 : true,
 #  endif
 #endif  // HAS_DEDUCTION_GUIDES
 
-#ifndef HAS_STRING_VIEW
-#  if __cplusplus >= 201703
-#    define HAS_STRING_VIEW 1
-#  else
-#    define HAS_STRING_VIEW 0
-#  endif
-#endif  // HAS_STRING_VIEW
-
 #include "date.h"
 
 #if defined(_MSC_VER) && (_MSC_VER < 1900)