diff --git a/src/Extensions.h b/src/Extensions.h
index a99f9d569..472b45a91 100644
--- a/src/Extensions.h
+++ b/src/Extensions.h
@@ -51,6 +51,7 @@ namespace Extensions {
 namespace GL {
     #line 1
     namespace AMD {
+        _extension(GL,AMD,vertex_shader_layer,          GL210,  None) // #417
         _extension(GL,AMD,shader_trinary_minmax,        GL210,  None) // #428
     } namespace APPLE {
         _extension(GL,APPLE,flush_buffer_range,         GL210, GL300) // #321
diff --git a/src/Physics/CMakeLists.txt b/src/Physics/CMakeLists.txt
index e3eec9146..f577e1594 100644
--- a/src/Physics/CMakeLists.txt
+++ b/src/Physics/CMakeLists.txt
@@ -12,7 +12,9 @@ set(MagnumPhysics_SRCS
     ShapeGroup.cpp
     Sphere.cpp
 
+    Implementation/AbstractBoxRenderer.cpp
     Implementation/AbstractDebugRenderer.cpp
+    Implementation/AxisAlignedBoxRenderer.cpp
     Implementation/BoxRenderer.cpp)
 
 set(MagnumPhysics_HEADERS
diff --git a/src/Physics/DebugDrawResourceManager.cpp b/src/Physics/DebugDrawResourceManager.cpp
index c2f35c2f3..8e958bc57 100644
--- a/src/Physics/DebugDrawResourceManager.cpp
+++ b/src/Physics/DebugDrawResourceManager.cpp
@@ -13,6 +13,8 @@
     GNU Lesser General Public License version 3 for more details.
 */
 
+#define MAGNUM_RESOURCEMANAGER_DEFINE_INTERNALINSTANCE
+
 #include "DebugDrawResourceManager.h"
 
 #include "AbstractShaderProgram.h"
@@ -21,9 +23,11 @@
 #include "ResourceManager.h"
 #include "Shaders/FlatShader.h"
 #include "AbstractShape.h"
+#include "AxisAlignedBox.h"
 #include "Box.h"
 #include "ObjectShape.h"
 #include "ShapeGroup.h"
+#include "Implementation/AxisAlignedBoxRenderer.h"
 #include "Implementation/BoxRenderer.h"
 #include "Implementation/DebugRenderer.h"
 
@@ -39,11 +43,13 @@ template<std::uint8_t dimensions> SceneGraph::Drawable<dimensions>* DebugDrawRes
     return renderer;
 }
 
-template SceneGraph::Drawable<2>* DebugDrawResourceManager::createDebugRenderer(ObjectShape<2>* shape, ResourceKey options);
-template SceneGraph::Drawable<3>* DebugDrawResourceManager::createDebugRenderer(ObjectShape<3>* shape, ResourceKey options);
+template SceneGraph::Drawable<2> PHYSICS_EXPORT * DebugDrawResourceManager::createDebugRenderer(ObjectShape<2>* shape, ResourceKey options);
+template SceneGraph::Drawable<3> PHYSICS_EXPORT * DebugDrawResourceManager::createDebugRenderer(ObjectShape<3>* shape, ResourceKey options);
 
 void DebugDrawResourceManager::createDebugMesh(Implementation::DebugRenderer<2>* renderer, AbstractShape2D* shape) {
     switch(shape->type()) {
+        case AbstractShape2D::Type::AxisAlignedBox:
+            renderer->addRenderer(new Implementation::AxisAlignedBoxRenderer<2>(*static_cast<AxisAlignedBox2D*>(shape)));
         case AbstractShape2D::Type::Box:
             renderer->addRenderer(new Implementation::BoxRenderer<2>(*static_cast<Box2D*>(shape)));
             break;
diff --git a/src/Physics/DebugDrawResourceManager.h b/src/Physics/DebugDrawResourceManager.h
index 618b594eb..c8253dfbf 100644
--- a/src/Physics/DebugDrawResourceManager.h
+++ b/src/Physics/DebugDrawResourceManager.h
@@ -21,7 +21,12 @@
 
 #include "Magnum.h"
 #include "Color.h"
+
+#ifndef MAGNUM_RESOURCEMANAGER_DEFINE_INTERNALINSTANCE
+#define MAGNUM_RESOURCEMANAGER_DONT_DEFINE_INTERNALINSTANCE
+#endif
 #include "ResourceManager.h"
+
 #include "SceneGraph/SceneGraph.h"
 
 #include "magnumPhysicsVisibility.h"
@@ -41,6 +46,8 @@ namespace Physics { namespace Implementation {
 }}
 #endif
 
+extern template ResourceManager<AbstractShaderProgram, Buffer, Mesh, Physics::Implementation::Options> PHYSICS_EXPORT *& ResourceManager<AbstractShaderProgram, Buffer, Mesh, Physics::Implementation::Options>::internalInstance();
+
 namespace Physics {
 
 template<std::uint8_t> class AbstractShape;
diff --git a/src/Physics/Implementation/AbstractBoxRenderer.cpp b/src/Physics/Implementation/AbstractBoxRenderer.cpp
new file mode 100644
index 000000000..95e7cdaeb
--- /dev/null
+++ b/src/Physics/Implementation/AbstractBoxRenderer.cpp
@@ -0,0 +1,70 @@
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+#include "AbstractBoxRenderer.h"
+
+#include "Buffer.h"
+#include "Physics/DebugDrawResourceManager.h"
+#include "Primitives/Cube.h"
+#include "Primitives/Square.h"
+#include "Shaders/FlatShader.h"
+
+namespace Magnum { namespace Physics { namespace Implementation {
+
+namespace {
+    template<std::uint8_t> struct BoxMesh {};
+
+    template<> struct BoxMesh<2> {
+        static ResourceKey shader() { return {"shader2d"}; }
+        static ResourceKey key() { return {"box2d"}; }
+
+        static Mesh* mesh(Buffer* buffer) {
+            Primitives::Square square;
+            Mesh* mesh = new Mesh;
+            buffer->setData(*square.positions(0), Buffer::Usage::StaticDraw);
+            return mesh->setPrimitive(square.primitive())
+                ->setVertexCount(square.positions(0)->size())
+                ->addVertexBuffer(buffer, Shaders::FlatShader<2>::Position());
+        }
+    };
+
+    template<> struct BoxMesh<3> {
+        static ResourceKey shader() { return {"shader3d"}; }
+        static ResourceKey key() { return {"box3d"}; }
+
+        static Mesh* mesh(Buffer* buffer) {
+            Primitives::Cube cube;
+            Mesh* mesh = new Mesh;
+            buffer->setData(*cube.positions(0), Buffer::Usage::StaticDraw);
+            return mesh->setPrimitive(cube.primitive())
+                ->setVertexCount(cube.positions(0)->size())
+                ->addVertexBuffer(buffer, Shaders::FlatShader<2>::Position());
+        }
+    };
+}
+
+template<std::uint8_t dimensions> AbstractBoxRenderer<dimensions>::AbstractBoxRenderer(): AbstractDebugRenderer<dimensions>(BoxMesh<dimensions>::shader(), BoxMesh<dimensions>::key()), buffer(DebugDrawResourceManager::instance()->get<Buffer>(BoxMesh<dimensions>::key())) {
+    if(!this->mesh) {
+        DebugDrawResourceManager::instance()->set(this->buffer.key(), new Buffer, ResourceDataState::Final, ResourcePolicy::Manual);
+        DebugDrawResourceManager::instance()->set<Mesh>(this->mesh.key(), BoxMesh<dimensions>::mesh(buffer), ResourceDataState::Final, ResourcePolicy::Manual);
+    }
+}
+
+template<std::uint8_t dimensions> AbstractBoxRenderer<dimensions>::~AbstractBoxRenderer() {}
+
+template class AbstractBoxRenderer<2>;
+template class AbstractBoxRenderer<3>;
+
+}}}
diff --git a/src/Physics/Implementation/AbstractBoxRenderer.h b/src/Physics/Implementation/AbstractBoxRenderer.h
new file mode 100644
index 000000000..87c57687e
--- /dev/null
+++ b/src/Physics/Implementation/AbstractBoxRenderer.h
@@ -0,0 +1,40 @@
+#ifndef Magnum_Physics_Implementation_AbstractBoxRenderer_h
+#define Magnum_Physics_Implementation_AbstractBoxRenderer_h
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+#include "AbstractDebugRenderer.h"
+
+#include "magnumCompatibility.h"
+
+namespace Magnum {
+
+class Buffer;
+
+namespace Physics { namespace Implementation {
+
+template<std::uint8_t dimensions> class AbstractBoxRenderer: public AbstractDebugRenderer<dimensions> {
+    public:
+        AbstractBoxRenderer();
+
+        ~AbstractBoxRenderer();
+
+    protected:
+        Resource<Buffer> buffer;
+};
+
+}}}
+
+#endif
diff --git a/src/Physics/Implementation/AbstractShapeRenderer.cpp b/src/Physics/Implementation/AbstractShapeRenderer.cpp
new file mode 100644
index 000000000..ee4d3596e
--- /dev/null
+++ b/src/Physics/Implementation/AbstractShapeRenderer.cpp
@@ -0,0 +1,32 @@
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+#include "AbstractShapeRenderer.h"
+
+#include "AbstractShaderProgram.h"
+#include "Mesh.h"
+#include "Physics/DebugDrawResourceManager.h"
+#include "Shaders/FlatShader.h"
+
+namespace Magnum { namespace Physics { namespace Implementation {
+
+template<std::uint8_t dimensions> AbstractShapeRenderer<dimensions>::AbstractShapeRenderer(ResourceKey shader, ResourceKey mesh): shader(DebugDrawResourceManager::instance()->get<AbstractShaderProgram, Shaders::FlatShader<dimensions>>(shader)), mesh(DebugDrawResourceManager::instance()->get<Mesh>(mesh)) {}
+
+template<std::uint8_t dimensions> AbstractShapeRenderer<dimensions>::~AbstractShapeRenderer() {}
+
+template class AbstractShapeRenderer<2>;
+template class AbstractShapeRenderer<3>;
+
+}}}
diff --git a/src/Physics/Implementation/AbstractShapeRenderer.h b/src/Physics/Implementation/AbstractShapeRenderer.h
new file mode 100644
index 000000000..276d53ba2
--- /dev/null
+++ b/src/Physics/Implementation/AbstractShapeRenderer.h
@@ -0,0 +1,50 @@
+#ifndef Magnum_Physics_Implementation_AbstractShapeRenderer_h
+#define Magnum_Physics_Implementation_AbstractShapeRenderer_h
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+#include "DimensionTraits.h"
+#include "ResourceManager.h"
+#include "SceneGraph/SceneGraph.h"
+
+namespace Magnum {
+
+class AbstractShaderProgram;
+class Mesh;
+
+namespace Shaders {
+    template<std::uint8_t> class FlatShader;
+}
+
+namespace Physics { namespace Implementation {
+
+struct Options;
+
+template<std::uint8_t dimensions> class AbstractShapeRenderer {
+    public:
+        AbstractShapeRenderer(ResourceKey shader, ResourceKey mesh);
+
+        virtual ~AbstractShapeRenderer();
+
+        virtual void draw(Resource<Options>& options, const typename DimensionTraits<dimensions>::MatrixType& transformationMatrix, SceneGraph::AbstractCamera<dimensions, GLfloat>* camera) = 0;
+
+    protected:
+        Resource<AbstractShaderProgram, Shaders::FlatShader<dimensions>> shader;
+        Resource<Mesh> mesh;
+};
+
+}}}
+
+#endif
diff --git a/src/Physics/Implementation/AxisAlignedBoxRenderer.cpp b/src/Physics/Implementation/AxisAlignedBoxRenderer.cpp
new file mode 100644
index 000000000..57e701116
--- /dev/null
+++ b/src/Physics/Implementation/AxisAlignedBoxRenderer.cpp
@@ -0,0 +1,38 @@
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+#include "AxisAlignedBoxRenderer.h"
+
+#include "Mesh.h"
+#include "Physics/DebugDrawResourceManager.h"
+#include "SceneGraph/AbstractCamera.h"
+#include "Shaders/FlatShader.h"
+
+namespace Magnum { namespace Physics { namespace Implementation {
+
+template<std::uint8_t dimensions> void AxisAlignedBoxRenderer<dimensions>::draw(Resource<Options>& options, const typename DimensionTraits<dimensions, GLfloat>::MatrixType&, typename SceneGraph::AbstractCamera<dimensions>* camera) {
+    typename DimensionTraits<dimensions>::MatrixType transformation =
+        DimensionTraits<dimensions>::MatrixType::translation(axisAlignedBox.transformedPosition())*
+        DimensionTraits<dimensions>::MatrixType::scaling(axisAlignedBox.transformedSize());
+    this->shader->setTransformationProjection(camera->projectionMatrix()*camera->cameraMatrix()*transformation)
+        ->setColor(options->color)
+        ->use();
+    this->mesh->draw();
+}
+
+template class AxisAlignedBoxRenderer<2>;
+template class AxisAlignedBoxRenderer<3>;
+
+}}}
diff --git a/src/Physics/Implementation/AxisAlignedBoxRenderer.h b/src/Physics/Implementation/AxisAlignedBoxRenderer.h
new file mode 100644
index 000000000..5ee7062ec
--- /dev/null
+++ b/src/Physics/Implementation/AxisAlignedBoxRenderer.h
@@ -0,0 +1,38 @@
+#ifndef Magnum_Physics_Implementation_AxisAlignedBoxRenderer_h
+#define Magnum_Physics_Implementation_AxisAlignedBoxRenderer_h
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+#include "AbstractBoxRenderer.h"
+
+#include "Physics/AxisAlignedBox.h"
+
+#include "magnumCompatibility.h"
+
+namespace Magnum { namespace Physics { namespace Implementation {
+
+template<std::uint8_t dimensions> class AxisAlignedBoxRenderer: public AbstractBoxRenderer<dimensions> {
+    public:
+        inline AxisAlignedBoxRenderer(AxisAlignedBox<dimensions>& axisAlignedBox): axisAlignedBox(axisAlignedBox) {}
+
+        void draw(Resource<Options>& options, const typename DimensionTraits<dimensions>::MatrixType& transformation, typename SceneGraph::AbstractCamera<dimensions>* camera) override;
+
+    private:
+        AxisAlignedBox<dimensions>& axisAlignedBox;
+};
+
+}}}
+
+#endif
diff --git a/src/Physics/Implementation/BoxRenderer.cpp b/src/Physics/Implementation/BoxRenderer.cpp
index a6cc9d4ca..1624e7aa3 100644
--- a/src/Physics/Implementation/BoxRenderer.cpp
+++ b/src/Physics/Implementation/BoxRenderer.cpp
@@ -15,55 +15,13 @@
 
 #include "BoxRenderer.h"
 
-#include "Buffer.h"
-#include "Physics/Box.h"
+#include "Mesh.h"
 #include "Physics/DebugDrawResourceManager.h"
-#include "Primitives/Cube.h"
-#include "Primitives/Square.h"
 #include "SceneGraph/AbstractCamera.h"
 #include "Shaders/FlatShader.h"
 
 namespace Magnum { namespace Physics { namespace Implementation {
 
-namespace {
-    template<std::uint8_t> struct BoxMesh {};
-
-    template<> struct BoxMesh<2> {
-        static ResourceKey shader() { return {"shader2d"}; }
-        static ResourceKey key() { return {"box2d"}; }
-
-        static Mesh* mesh(Buffer* buffer) {
-            Primitives::Square square;
-            Mesh* mesh = new Mesh;
-            buffer->setData(*square.positions(0), Buffer::Usage::StaticDraw);
-            return mesh->setPrimitive(square.primitive())
-                ->setVertexCount(square.positions(0)->size())
-                ->addVertexBuffer(buffer, Shaders::FlatShader<2>::Position());
-        }
-    };
-
-    template<> struct BoxMesh<3> {
-        static ResourceKey shader() { return {"shader3d"}; }
-        static ResourceKey key() { return {"box3d"}; }
-
-        static Mesh* mesh(Buffer* buffer) {
-            Primitives::Cube cube;
-            Mesh* mesh = new Mesh;
-            buffer->setData(*cube.positions(0), Buffer::Usage::StaticDraw);
-            return mesh->setPrimitive(cube.primitive())
-                ->setVertexCount(cube.positions(0)->size())
-                ->addVertexBuffer(buffer, Shaders::FlatShader<2>::Position());
-        }
-    };
-}
-
-template<std::uint8_t dimensions> BoxRenderer<dimensions>::BoxRenderer(Box<dimensions>& box): AbstractDebugRenderer<dimensions>(BoxMesh<dimensions>::shader(), BoxMesh<dimensions>::key()), buffer(DebugDrawResourceManager::instance()->get<Buffer>(BoxMesh<dimensions>::key())), box(box) {
-    if(!this->mesh) {
-        DebugDrawResourceManager::instance()->set(this->buffer.key(), new Buffer, ResourceDataState::Final, ResourcePolicy::Manual);
-        DebugDrawResourceManager::instance()->set<Mesh>(this->mesh.key(), BoxMesh<dimensions>::mesh(buffer), ResourceDataState::Final, ResourcePolicy::Manual);
-    }
-}
-
 template<std::uint8_t dimensions> void BoxRenderer<dimensions>::draw(Resource<Options>& options, const typename DimensionTraits<dimensions, GLfloat>::MatrixType&, typename SceneGraph::AbstractCamera<dimensions>* camera) {
     this->shader->setTransformationProjection(camera->projectionMatrix()*camera->cameraMatrix()*box.transformedTransformation())
         ->setColor(options->color)
diff --git a/src/Physics/Implementation/BoxRenderer.h b/src/Physics/Implementation/BoxRenderer.h
index d563c7c63..c1e248478 100644
--- a/src/Physics/Implementation/BoxRenderer.h
+++ b/src/Physics/Implementation/BoxRenderer.h
@@ -15,28 +15,21 @@
     GNU Lesser General Public License version 3 for more details.
 */
 
-#include "AbstractDebugRenderer.h"
+#include "AbstractBoxRenderer.h"
 
-#include "magnumCompatibility.h"
-
-namespace Magnum {
-
-class Buffer;
+#include "Physics/Box.h"
 
-namespace Physics {
-
-template<std::uint8_t> class Box;
+#include "magnumCompatibility.h"
 
-namespace Implementation {
+namespace Magnum { namespace Physics { namespace Implementation {
 
-template<std::uint8_t dimensions> class BoxRenderer: public AbstractDebugRenderer<dimensions> {
+template<std::uint8_t dimensions> class BoxRenderer: public AbstractBoxRenderer<dimensions> {
     public:
-        BoxRenderer(Box<dimensions>& box);
+        inline BoxRenderer(Box<dimensions>& box): box(box) {}
 
         void draw(Resource<Options>& options, const typename DimensionTraits<dimensions>::MatrixType& transformation, typename SceneGraph::AbstractCamera<dimensions, GLfloat>* camera) override;
 
     private:
-        Resource<Buffer> buffer;
         Box<dimensions>& box;
 };
 
diff --git a/src/ResourceManager.h b/src/ResourceManager.h
index 0d0a3538d..bd164e741 100644
--- a/src/ResourceManager.h
+++ b/src/ResourceManager.h
@@ -461,7 +461,10 @@ cube->draw();
 template<class... Types> class ResourceManager: protected Implementation::ResourceManagerData<Types>... {
     public:
         /** @brief Global instance */
-        inline static ResourceManager<Types...>* instance() { return _instance; }
+        inline static ResourceManager<Types...>* instance() {
+            CORRADE_ASSERT(internalInstance(), "ResourceManager::instance(): no instance exists", nullptr);
+            return internalInstance();
+        }
 
         /**
          * @brief Constructor
@@ -472,8 +475,8 @@ template<class... Types> class ResourceManager: protected Implementation::Resour
          * @see instance()
          */
         inline ResourceManager() {
-            CORRADE_ASSERT(!_instance, "ResourceManager: another instance is already created!", );
-            _instance = this;
+            CORRADE_ASSERT(!internalInstance(), "ResourceManager::ResourceManager(): another instance is already created", );
+            internalInstance() = this;
         }
 
         /**
@@ -482,7 +485,10 @@ template<class... Types> class ResourceManager: protected Implementation::Resour
          * Sets global instance pointer to `nullptr`.
          * @see instance()
          */
-        inline ~ResourceManager() { _instance = nullptr; }
+        inline ~ResourceManager() {
+            CORRADE_INTERNAL_ASSERT(internalInstance() == this);
+            internalInstance() = nullptr;
+        }
 
         /** @brief Count of resources of given type */
         template<class T> inline std::size_t count() {
@@ -567,16 +573,21 @@ template<class... Types> class ResourceManager: protected Implementation::Resour
         }
         inline void freeInternal() const {}
 
-        static ResourceManager<Types...>* _instance;
+        static ResourceManager<Types...>*& internalInstance();
 };
 
+#ifndef MAGNUM_RESOURCEMANAGER_DONT_DEFINE_INTERNALINSTANCE
+template<class ...Types> ResourceManager<Types...>*& ResourceManager<Types...>::internalInstance() {
+    static ResourceManager<Types...>* _instance(nullptr);
+    return _instance;
+}
+#endif
+
 /** @debugoperator{Magnum::ResourceKey} */
 template<class T> inline Corrade::Utility::Debug operator<<(Corrade::Utility::Debug debug, const ResourceKey& value) {
     return debug << static_cast<const Corrade::Utility::HashDigest<sizeof(std::size_t)>&>(value);
 }
 
-template<class ...Types> ResourceManager<Types...>* ResourceManager<Types...>::_instance(nullptr);
-
 }
 
 #endif