Added HashCombine function

Former-commit-id: 852deae33143138f2841e226690bfef94d3ba2b9

include/Nazara/Core/Algorithm.inl

@@ -30,6 +30,23 @@ struct NzImplTupleUnpack<0>
 	}
 };
 
+// Algorithme venant de CityHash par Google
+// http://stackoverflow.com/questions/8513911/how-to-create-a-good-hash-combine-with-64-bit-output-inspired-by-boosthash-co
+template<typename T>
+void NzHashCombine(std::size_t& seed, const T& v)
+{
+    const std::size_t kMul = 0x9ddfea08eb382d69ULL;
+
+    std::hash<T> hasher;
+    std::size_t a = (hasher(v) ^ seed) * kMul;
+    a ^= (a >> 47);
+
+    std::size_t b = (seed ^ a) * kMul;
+    b ^= (b >> 47);
+
+    seed = b * kMul;
+}
+
 template<typename F, typename... ArgsT>
 void NzUnpackTuple(F func, const std::tuple<ArgsT...>& t)
 {