From 091efebaa174289ade2a13b34ac8f9188c1bc683 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Tue, 30 Jul 2013 23:07:30 +0200
Subject: [PATCH] Make explicit `std::hash` specialization for ResourceKey.

Allows users to use ResourceKey in `std::unordered_map` more
conveniently.
---
 src/Magnum.h          |  7 +++++++
 src/Resource.h        | 11 +++++++++++
 src/ResourceManager.h |  8 +-------
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/Magnum.h b/src/Magnum.h
index a54c2467c..13eeb2b92 100644
--- a/src/Magnum.h
+++ b/src/Magnum.h
@@ -419,4 +419,11 @@ class Timeline;
 
 }
 
+namespace std {
+    #ifndef DOXYGEN_GENERATING_OUTPUT
+    template<class> struct hash;
+    #endif
+    template<> struct hash<Magnum::ResourceKey>;
+}
+
 #endif
diff --git a/src/Resource.h b/src/Resource.h
index cf71f7998..888f2b6dd 100644
--- a/src/Resource.h
+++ b/src/Resource.h
@@ -277,6 +277,17 @@ template<class T, class U> void Resource<T, U>::acquire() {
 
 }
 
+namespace std {
+    /** @brief `std::hash` specialization for @ref Magnum::ResourceKey */
+    template<> struct hash<Magnum::ResourceKey> {
+        #ifndef DOXYGEN_GENERATING_OUTPUT
+        std::size_t operator()(Magnum::ResourceKey key) const {
+            return *reinterpret_cast<const std::size_t*>(key.byteArray());
+        }
+        #endif
+    };
+}
+
 /* Make the definition complete */
 #include "ResourceManager.h"
 
diff --git a/src/ResourceManager.h b/src/ResourceManager.h
index 0831ac727..acb3a1553 100644
--- a/src/ResourceManager.h
+++ b/src/ResourceManager.h
@@ -91,12 +91,6 @@ template<class> class AbstractResourceLoader;
 
 namespace Implementation {
 
-struct ResourceKeyHash {
-    std::size_t operator()(ResourceKey key) const {
-        return *reinterpret_cast<const std::size_t*>(key.byteArray());
-    }
-};
-
 template<class T> class ResourceManagerData {
     template<class, class> friend class Magnum::Resource;
     friend class AbstractResourceLoader<T>;
@@ -147,7 +141,7 @@ template<class T> class ResourceManagerData {
 
         void decrementReferenceCount(ResourceKey key);
 
-        std::unordered_map<ResourceKey, Data, ResourceKeyHash> _data;
+        std::unordered_map<ResourceKey, Data> _data;
         T* _fallback;
         AbstractResourceLoader<T>* _loader;
         std::size_t _lastChange;