Added std::hash for String, made use of unordered_map

Former-commit-id: 20f3d12bc3222873706949f0a7d0a131e237a247

include/Nazara/Core/String.hpp

@@ -323,4 +323,6 @@ namespace std
 	NAZARA_API void swap(NzString& lhs, NzString& rhs);
 }
 
+#include <Nazara/Core/String.inl>
+
 #endif // NAZARA_STRING_HPP

include/Nazara/Core/String.inl

@@ -0,0 +1,33 @@
+// Copyright (C) 2013 Jérôme Leclercq
+// This file is part of the "Nazara Engine - Core module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Core/Debug.hpp>
+
+namespace std
+{
+    template<>
+    struct hash<NzString>
+    {
+		public:
+			size_t operator()(const NzString& str) const
+			{
+				// Algorithme DJB2
+				// http://www.cse.yorku.ca/~oz/hash.html
+
+				size_t h = 5381;
+				if (!str.IsEmpty())
+				{
+					const char* ptr = str.GetConstBuffer();
+
+					do
+						h = ((h << 5) + h) + *ptr;
+					while (*++ptr);
+				}
+
+				return h;
+			}
+    };
+}
+
+#include <Nazara/Core/DebugOff.hpp>