From bce2f81d2f74ecd919704d43fb0c0f5499d50254 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Fri, 19 Dec 2014 15:00:33 +1100
Subject: [PATCH] point: add trivial std::hash specialisation

---
 point.hpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/point.hpp b/point.hpp
index b9553d8e..2e3693b6 100644
--- a/point.hpp
+++ b/point.hpp
@@ -82,6 +82,24 @@ namespace util {
     typedef point<2,size_t> point2u;
 }
 
+#include <functional>
+
+namespace std {
+    template <>
+    template <size_t S, typename T>
+    struct hash<util::point<S,T>> {
+        size_t operator() (const util::point<S,T> &p) const {
+            std::hash<T> h;
+
+            size_t k = 0;
+            for (size_t i = 0; i < S; ++i)
+                k = h (p.data[i] ^ k);
+
+            return k;
+        }
+    };
+}
+
 #include "point.ipp"
 
 #endif // __UTIL_POINT_HPP