traits: add is_native/is_wrapper queries

traits.hpp

@@ -118,6 +118,52 @@ namespace cruft::vk {
     using native_t = typename native_traits<T>::type;
 
 
+    ///////////////////////////////////////////////////////////////////////////
+    /// defines whether a type is a native vulkan object.
+    ///
+    /// note that this only returns true for handle types, not parameter types.
+    /// eg, VkDevice will return true, but VkDeviceCreateInfo will not.
+    template <typename>
+    struct is_native : public std::false_type { };
+
+
+    //-------------------------------------------------------------------------
+    #define DEFINE_IS_HANDLE(KLASS)     \
+    template <>                         \
+    struct is_native<native_t<KLASS>> : \
+         public std::true_type          \
+    { };
+
+    VK_TYPE_MAP (DEFINE_IS_HANDLE)
+    #undef DEFINE_IS_HANDLE
+
+
+    //-------------------------------------------------------------------------
+    template <typename T>
+    static constexpr auto is_native_v = is_native<T>::value;
+
+
+    ///////////////////////////////////////////////////////////////////////////
+    template <typename>
+    struct is_wrapper : public std::false_type { };
+
+
+    //-------------------------------------------------------------------------
+    #define IS_WRAPPER(KLASS)   \
+    template <>                 \
+    struct is_wrapper<KLASS> :  \
+        public std::true_type   \
+    { };
+
+    VK_TYPE_MAP(IS_WRAPPER)
+    #undef IS_WRAPPER
+
+
+    //-------------------------------------------------------------------------
+    template <typename T>
+    static constexpr auto is_wrapper_v = is_wrapper<T>::value;
+
+
     ///////////////////////////////////////////////////////////////////////////
     /// describes the native type that owns a given native type, and hence
     /// forms part of the create/destroy process.