unique_handle.hpp

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
#pragma once
#include <memory>
 
namespace Azure { namespace Core {
  namespace _detail {
    // *** Given just T, map it to the corresponding FreeFunc
    template <typename T> struct UniqueHandleHelper;
  } // namespace _detail
 
  namespace _internal {
    template <typename T, void (&Deleter)(T*)> struct UniqueHandleDeleter
    {
      void operator()(T* obj) { Deleter(obj); }
    };
 
    template <typename T, void (&FreeFunc)(T*)>
    using BasicUniqueHandle = std::unique_ptr<T, UniqueHandleDeleter<T, FreeFunc>>;
 
    // *** Now users can say UniqueHandle<T> if they want:
    template <typename T, template <typename> class U = _detail::UniqueHandleHelper>
    using UniqueHandle = typename U<T>::type;
  } // namespace _internal
 
  namespace _detail {
    void FreeWinHttpHandleImpl(void* obj);
 
    template <> struct UniqueHandleHelper<void*>
    {
      static void FreeWinHttpHandle(void* obj) { FreeWinHttpHandleImpl(obj); }
 
      using type = _internal::BasicUniqueHandle<void, FreeWinHttpHandle>;
    };
  } // namespace _detail
}} // namespace Azure::Core