Move array hasher defintion to util.cpp

surfseg/include/util.h

@@ -16,16 +16,7 @@ namespace std {
 
     template <size_t N>
     struct hash<std::array<int, N>> {
-        size_t operator()(const std::array<int, N>& key) const
-        {
-            // Code from https://codereview.stackexchange.com/q/171999
-            static std::hash<int> hasher;
-            size_t result = 0;
-            for (int k : key) {
-                result = result * 31 + hasher(k);
-            }
-            return result;
-        }
+        size_t operator()(const std::array<int, N>& key) const noexcept;
     };
 } // std
 

surfseg/src/util.cpp

@@ -8,6 +8,18 @@ size_t std::hash<std::pair<int, int>>::operator()(const std::pair<int, int>& key
     return hasher(tohash);
 }
 
+template <size_t N>
+size_t std::hash<std::array<int, N>>::operator()(const std::array<int, N>& key) const noexcept
+{
+    // Code from https://codereview.stackexchange.com/q/171999
+    static std::hash<int> hasher;
+    size_t result = 0;
+    for (int k : key) {
+        result = result * 31 + hasher(k);
+    }
+    return result;
+}
+
 void graphErrFunc(const char *msg)
 {
 	// To avoid crashing the program we throw an exception here since Graph will otherwise call exit(1)