Implement optional static polymorphism instead of direct inheritance from interface

cpp/Platform.Memory/ArrayMemory.h

@@ -1,7 +1,7 @@
 namespace Platform::Memory
 {
     template <typename ...> class ArrayMemory;
-    template <typename TElement> class ArrayMemory<TElement> : public IArrayMemory<TElement>
+    template <typename TElement> class ArrayMemory<TElement> : public Polymorph<ArrayMemory<TElement>, IArrayMemory<TElement>>
     {
         private: std::vector<TElement> _array{};
 

cpp/Platform.Memory/DirectMemoryAsArrayMemoryAdapter.h

@@ -2,7 +2,7 @@
 {
     template <typename ...> class DirectMemoryAsArrayMemoryAdapter;
     template <typename TElement> class DirectMemoryAsArrayMemoryAdapter<TElement> :
-        public IArrayMemory<TElement>, public IDirectMemory
+        public Polymorph<DirectMemoryAsArrayMemoryAdapter<TElement>, IArrayMemory<TElement>, IDirectMemory>
     {
         using Self = DirectMemoryAsArrayMemoryAdapter<TElement>;
         using IDirectMemory::pointer_t;
@@ -14,12 +14,12 @@
             return _memory.Size();
         }
 
-        public: pointer_t& Pointer()
+        public: IDirectMemory::pointer_t& Pointer()
         {
             return _memory.Pointer();
         }
 
-        public: const pointer_t& Pointer() const
+        public: const IDirectMemory::pointer_t& Pointer() const
         {
             return _memory.Pointer();
         }

cpp/Platform.Memory/FileArrayMemory.h

@@ -10,7 +10,7 @@
     };
 
     template <typename ...> class FileArrayMemory;
-    template <typename TElement> class FileArrayMemory<TElement> final : public IArrayMemory<TElement>
+    template <typename TElement> class FileArrayMemory<TElement> final : public Polymorph<FileArrayMemory<TElement>, IArrayMemory<TElement>>
         //where TElement : struct
     {
         using Self = FileArrayMemory<TElement>;

cpp/Platform.Memory/FileMappedResizableDirectMemory.h

@@ -1,6 +1,6 @@
 namespace Platform::Memory
 {
-    class FileMappedResizableDirectMemory final : public ResizableDirectMemoryBase
+    class FileMappedResizableDirectMemory final : public Polymorph<FileMappedResizableDirectMemory, ResizableDirectMemoryBase>
     {
       using base = ResizableDirectMemoryBase;
         protected: using base::capacity_t;

cpp/Platform.Memory/HeapResizableDirectMemory.h

@@ -20,7 +20,7 @@
         }
     }
 
-    class HeapResizableDirectMemory final : public ResizableDirectMemoryBase
+    class HeapResizableDirectMemory final : public Polymorph<HeapResizableDirectMemory, ResizableDirectMemoryBase>
     {
         using ResizableDirectMemoryBase::capacity_t;
         //protected: override std::string ObjectName

cpp/Platform.Memory/Platform.Memory.h

@@ -15,6 +15,7 @@
 #include "memory_mapped_file.hpp"
 #include "memory_mapped_file.cpp"
 
+#include "Polymorph.h"
 #include "IMemory.h"
 #include "IDirectMemory.h"
 #include "IArrayMemory.h"

cpp/Platform.Memory/Polymorph.h

@@ -0,0 +1,18 @@
+namespace Platform::Memory
+{
+    template <typename TSelf, typename... TBase>
+    class Polymorph : public TBase...
+    {
+    public:
+        // Optional static polymorphism - allows getting the derived type
+        TSelf& self() { return static_cast<TSelf&>(*this); }
+        const TSelf& self() const { return static_cast<const TSelf&>(*this); }
+
+        // Enable perfect forwarding to derived class methods
+        template<typename T = TSelf>
+        T& as() { return static_cast<T&>(*this); }
+
+        template<typename T = TSelf>
+        const T& as() const { return static_cast<const T&>(*this); }
+    };
+}

cpp/Platform.Memory/ResizableDirectMemoryBase.h

@@ -1,4 +1,6 @@
-namespace Platform::Memory
+#include <type_traits>
+
+namespace Platform::Memory
 {
     namespace Internal
     {

cpp/Platform.Memory/TemporaryFileMappedResizableDirectMemory.h

@@ -1,6 +1,6 @@
 namespace Platform::Memory
 {
-    class TemporaryFileMappedResizableDirectMemory final : public ResizableDirectMemoryBase
+    class TemporaryFileMappedResizableDirectMemory final : public Polymorph<TemporaryFileMappedResizableDirectMemory, ResizableDirectMemoryBase>
     {
         using base_t = FileMappedResizableDirectMemory;
         base_t base;