From 54c67dcfec158324201a8db84a423e2ba3b7c507 Mon Sep 17 00:00:00 2001
From: traits <os@traits.de>
Date: Thu, 10 Aug 2017 09:05:00 +0200
Subject: [PATCH] Update json.hpp

---
 src/json.hpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/json.hpp b/src/json.hpp
index 9a04a62b..efd76da7 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -14492,7 +14492,8 @@ struct hash<nlohmann::json>
 
 /// specialization for std::less<value_t>
 template<>
-struct less<nlohmann::detail::value_t>
+struct less< ::nlohmann::detail::value_t> // do not remove the space after '<', 
+                                          // see https://github.com/nlohmann/json/pull/679
 {
     /*!
     @brief compare two value_t enum values