I didn't expect new GCC would behave worse with deprecation warnings.

By now I tested on GCC 4.8, various Clang versions, most MSVC versions,
building the library was without warnings on all those, and so I
expected newer GCC to be also silent when it should be. Nope. Ugh.

src/Magnum/Resource.h

@@ -66,7 +66,10 @@ namespace Magnum {
 
 @see @ref Resource::state(), @ref ResourceManager::state()
 */
-enum class CORRADE_DEPRECATED_ENUM("the ResourceManager class is obsolete") ResourceState: UnsignedByte {
+/* No CORRADE_DEPRECATED_ENUM() here, as it's already on the declaration in
+   Magnum.h and GCC stupidly warns that "type attributes ignored after type is
+   already defined". Happens for the other Resource* enums as well. */
+enum class ResourceState: UnsignedByte {
     /** The resource is not yet loaded (and no fallback is available). */
     NotLoaded,
 
@@ -179,15 +182,21 @@ class
          * Creates empty resource. Resources are acquired from the manager by
          * calling @ref ResourceManager::get().
          */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         explicit Resource(): _manager{nullptr}, _lastCheck{0}, _state{ResourceState::Final}, _data{nullptr} {}
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @brief Copy constructor */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         Resource(const Resource<T, U>& other): _manager{other._manager}, _key{other._key}, _lastCheck{other._lastCheck}, _state{other._state}, _data{other._data} {
             if(_manager) _manager->incrementReferenceCount(_key);
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @brief Move constructor */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         Resource(Resource<T, U>&& other) noexcept;
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @brief Destructor */
         ~Resource() {
@@ -195,15 +204,21 @@ class
         }
 
         /** @brief Copy assignment */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         Resource<T, U>& operator=(const Resource<T, U>& other);
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @brief Move assignment */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         Resource<T, U>& operator=(Resource<T, U>&& other) noexcept;
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @brief Equality comparison */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         bool operator==(const Resource<T, U>& other) const {
             return _manager == other._manager && _key == other._key;
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @brief Equality comparison with other types is explicitly disallowed */
         CORRADE_IGNORE_DEPRECATED_PUSH /* MSVC warns here */
@@ -211,9 +226,11 @@ class
         CORRADE_IGNORE_DEPRECATED_POP
 
         /** @brief Non-equality comparison */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         bool operator!=(const Resource<T, U>& other) const {
             return !operator==(other);
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @brief Non-equality comparison with other types is explicitly disallowed */
         CORRADE_IGNORE_DEPRECATED_PUSH /* MSVC warns here */

src/Magnum/ResourceManager.h

@@ -60,7 +60,10 @@ namespace Magnum {
 @see @ref ResourceManager::set(), @ref ResourceState
 */
 CORRADE_IGNORE_DEPRECATED_PUSH /* MSVC warns for ResourceState usage */
-enum class CORRADE_DEPRECATED_ENUM("the ResourceManager class is obsolete") ResourceDataState: UnsignedByte {
+/* No CORRADE_DEPRECATED_ENUM() here, as it's already on the declaration in
+   Magnum.h and GCC stupidly warns that "type attributes ignored after type is
+   already defined". Happens for the other Resource* enums as well. */
+enum class ResourceDataState: UnsignedByte {
     /**
      * The resource is currently loading. Parameter @p data in
      * @ref ResourceManager::set() should be set to @cpp nullptr @ce.
@@ -99,7 +102,10 @@ CORRADE_IGNORE_DEPRECATED_POP
 
 @see @ref ResourceManager::set(), @ref ResourceManager::free()
  */
-enum class CORRADE_DEPRECATED_ENUM("the ResourceManager class is obsolete") ResourcePolicy: UnsignedByte {
+/* No CORRADE_DEPRECATED_ENUM() here, as it's already on the declaration in
+   Magnum.h and GCC stupidly warns that "type attributes ignored after type is
+   already defined". Happens for the other Resource* enums as well. */
+enum class ResourcePolicy: UnsignedByte {
     /** The resource will stay resident for whole lifetime of resource manager. */
     Resident,
 
@@ -386,42 +392,52 @@ template<class... Types> class CORRADE_DEPRECATED("the ResourceManager class is
          * @brief Set fallback for not found resources
          * @return Reference to self (for method chaining)
          */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         template<class T> ResourceManager<Types...>& setFallback(T* data) {
             this->Implementation::ResourceManagerData<T>::setFallback(data);
             return *this;
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /**
          * @overload
          * @m_since{2019,10}
          */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         template<class T> ResourceManager<Types...>& setFallback(Containers::Pointer<T>&& data) {
             setFallback(data.release());
             return *this;
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @overload */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         template<class U> ResourceManager<Types...>& setFallback(U&& data) {
             return setFallback(new typename std::decay<U>::type(std::forward<U>(data)));
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /**
          * @brief Free all resources of given type which are not referenced
          * @return Reference to self (for method chaining)
          */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         template<class T> ResourceManager<Types...>& free() {
             this->Implementation::ResourceManagerData<T>::free();
             return *this;
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /**
          * @brief Free all resources which are not referenced
          * @return Reference to self (for method chaining)
          */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         ResourceManager<Types...>& free() {
             freeInternal(Implementation::ResourceTypePack<Types...>{});
             return *this;
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /**
          * @brief Clear all resources of given type
@@ -430,10 +446,12 @@ template<class... Types> class CORRADE_DEPRECATED("the ResourceManager class is
          * Unlike @ref free() this function assumes that no resource is
          * referenced.
          */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         template<class T> ResourceManager<Types...>& clear() {
             this->Implementation::ResourceManagerData<T>::clear();
             return *this;
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /**
          * @brief Clear all resources
@@ -442,10 +460,12 @@ template<class... Types> class CORRADE_DEPRECATED("the ResourceManager class is
          * Unlike @ref free() this function assumes that no resource is
          * referenced.
          */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         ResourceManager<Types...>& clear() {
             clearInternal(Implementation::ResourceTypePack<Types...>{});
             return *this;
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @brief Loader for given type of resources */
         template<class T> AbstractResourceLoader<T>* loader() {
@@ -467,15 +487,19 @@ template<class... Types> class CORRADE_DEPRECATED("the ResourceManager class is
          * @attention The loader is deleted on destruction before unloading
          *      all resources.
          */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         template<class T> ResourceManager<Types...>& setLoader(AbstractResourceLoader<T>* loader) {
             this->Implementation::ResourceManagerData<T>::setLoader(loader);
             return *this;
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
         /** @overload */
+        CORRADE_IGNORE_DEPRECATED_PUSH /* GCC except for 4.8 (!) warns here */
         template<class T> ResourceManager<Types...>& setLoader(Containers::Pointer<AbstractResourceLoader<T>>&& loader) {
             return setLoader(loader.release());
         }
+        CORRADE_IGNORE_DEPRECATED_POP
 
     private:
         template<class FirstType, class ...NextTypes> void freeInternal(Implementation::ResourceTypePack<FirstType, NextTypes...>) {