From c9b1d15ebe7aaa05ccb62cc4bbb5b47fd784ef62 Mon Sep 17 00:00:00 2001
From: Alexander van Gessel <ai0867@gmail.com>
Date: Wed, 22 Nov 2017 15:48:42 +0100
Subject: [PATCH] Bump minimum boost version for external string_view

---
 src/serialization/string_view.hpp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/serialization/string_view.hpp b/src/serialization/string_view.hpp
index e530b7b8b87a0..af9afa87c4d21 100644
--- a/src/serialization/string_view.hpp
+++ b/src/serialization/string_view.hpp
@@ -21,7 +21,14 @@ that class. */
 
 #include <boost/version.hpp>
 
-#if BOOST_VERSION > 106100
+/*
+ * Boost 1.61 already has string_view, but it fails to compile on some compilers.
+ * The problem is that in string_view::at's ternary expression,
+ * BOOST_THROW_EXCEPTION is not seen as a throw-expression. If a ternary branch
+ * is not a throw-expression, it must be of the same type as the other branch,
+ * necessitating the ', res[0]' workaround.
+ */
+#if BOOST_VERSION > 106400
 
 /* Boost string_view is available, so we can just use it. */
 #include <boost/utility/string_view.hpp>