From ecadcdb5938fb17ef238dcad031de0de37ccf57f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matthias=20M=C3=B6ller?= <m_moeller@live.de>
Date: Thu, 31 May 2018 16:36:16 +0200
Subject: [PATCH] added char cast

should fix the GCC unittest
---
 include/nlohmann/detail/output/serializer.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/nlohmann/detail/output/serializer.hpp b/include/nlohmann/detail/output/serializer.hpp
index f6fa152a..19ab9894 100644
--- a/include/nlohmann/detail/output/serializer.hpp
+++ b/include/nlohmann/detail/output/serializer.hpp
@@ -415,7 +415,7 @@ class serializer
         {
             // we finish reading, but do not accept: string was incomplete
             std::string sn(3,'\0');
-            snprintf(&sn[0], sn.size(), "%.2X", s.back());
+            snprintf(&sn[0], sn.size(), "%.2X", static_cast<uint8_t>(s.back()));
             JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + sn));
         }
     }