1 files changed, 16 insertions, 0 deletions
diff --git a/src/common/Common.h b/src/common/Common.h
index 605b6dc4ae8..2a492e0eeee 100644
--- a/src/common/Common.h
+++ b/src/common/Common.h
@@ -45,6 +45,7 @@
 
 #include <boost/optional.hpp>
 #include <boost/utility/in_place_factory.hpp>
+#include <boost/functional/hash.hpp>
 
 #include "Debugging/Errors.h"
 
@@ -178,4 +179,19 @@ namespace Trinity
     }
 }
 
+//! Hash implementation for std::pair to allow using pairs in unordered_set or as key for unordered_map
+//! Individual types used in pair must be hashable by boost::hash
+namespace std
+{
+    template<class K, class V>
+    struct hash<std::pair<K, V>>
+    {
+    public:
+        size_t operator()(std::pair<K, V> const& key) const
+        {
+            return boost::hash_value(key);
+        }
+    };
+}
+
 #endif