polymorphic_allocator_deleter.hpp

/*****************************************************************************
 * \file
 * \brief This header defines an allocator deleter that operates polymorphically
 *        with types, which comes at the cost of storing the size with each
 *        allocation
 *****************************************************************************/

/*
  The MIT License (MIT)

  Copyright (c) 2018 Matthew Rodusek

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
#ifndef BIT_MEMORY_ADAPTERS_POLYMORPHIC_ALLOCATOR_DELETER_HPP
#define BIT_MEMORY_ADAPTERS_POLYMORPHIC_ALLOCATOR_DELETER_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include "../utilities/ebo_storage.hpp"
#include "../utilities/pointer_utilities.hpp" // to_raw_pointer

#include "../concepts/AllocatorStorage.hpp"

#include "../traits/allocator_traits.hpp"

#include <cstddef>     // std::size_t, std::ptrdiff_t
#include <tuple>       // std::forward_as_tuple
#include <type_traits> // std::is_reference, std::is_const, etc
#include <utility>     // std::move
#include <memory>      // std::pointer_traits

namespace bit {
  namespace memory {

    template<typename T, typename AllocatorStorage>
    class polymorphic_allocator_deleter
      : private ebo_storage<AllocatorStorage>
    {
      using base_type = ebo_storage<AllocatorStorage>;
      using allocator_type = typename AllocatorStorage::allocator_type;

      using alloc_traits   = allocator_traits<allocator_type>;
      using pointer_traits = std::pointer_traits<typename alloc_traits::pointer>;

      static_assert( !std::is_reference<T>::value, "Unable to delete reference type" );
      static_assert( !std::is_const<T>::value, "Unable to delete const type" );
      static_assert( !std::is_void<T>::value, "Unable to delete void type" );
      static_assert( is_allocator_storage<AllocatorStorage>::value,
                     "AllocatorStorage must satisfy AllocatorStorage requirements" );

      //-----------------------------------------------------------------------
      // Public Member Types
      //-----------------------------------------------------------------------
    public:

      using void_pointer    = typename alloc_traits::pointer;
      using pointer         = typename pointer_traits::template rebind<T>;
      using size_type       = typename alloc_traits::size_type;
      using difference_type = typename alloc_traits::difference_type;

      //-----------------------------------------------------------------------
      // Constructor
      //-----------------------------------------------------------------------
    public:

      explicit polymorphic_allocator_deleter( AllocatorStorage storage ) noexcept;

      polymorphic_allocator_deleter( polymorphic_allocator_deleter&& other ) noexcept = default;

      polymorphic_allocator_deleter( const polymorphic_allocator_deleter& other ) noexcept = default;

      //-----------------------------------------------------------------------

      template<typename U,
               typename = std::enable_if_t<std::is_convertible<U,T>::value>>
      polymorphic_allocator_deleter( polymorphic_allocator_deleter<U,AllocatorStorage>&& other ) noexcept;

      template<typename U,
               typename = std::enable_if_t<std::is_convertible<U,T>::value>>
      polymorphic_allocator_deleter( const polymorphic_allocator_deleter<U,AllocatorStorage>& other ) noexcept;

      //-----------------------------------------------------------------------

      polymorphic_allocator_deleter&
        operator=( polymorphic_allocator_deleter&& other ) noexcept = default;

      polymorphic_allocator_deleter& operator=( const polymorphic_allocator_deleter& other ) noexcept = default;

      //-----------------------------------------------------------------------

      template<typename U,
               typename = std::enable_if_t<std::is_convertible<U,T>::value>>
      polymorphic_allocator_deleter&
        operator=( polymorphic_allocator_deleter<U,AllocatorStorage>&& other ) noexcept;

      template<typename U,
               typename = std::enable_if_t<std::is_convertible<U,T>::value>>
      polymorphic_allocator_deleter&
        operator=( const polymorphic_allocator_deleter<U,AllocatorStorage>& other ) noexcept;

      //-----------------------------------------------------------------------
      // Deallocation
      //-----------------------------------------------------------------------
    public:

      void operator()( pointer p );

      //-----------------------------------------------------------------------
      // Private Members
      //-----------------------------------------------------------------------
    private:

      size_type m_size;

      template<typename,typename> friend class polymorphic_allocator_deleter;

      //-----------------------------------------------------------------------
      // Private Observers
      //-----------------------------------------------------------------------
    private:

      AllocatorStorage storage() const noexcept;

      std::size_t size() const noexcept;
    };


    template<typename T, typename AllocatorStorage>
    class polymorphic_allocator_deleter<T[],AllocatorStorage>
      : private ebo_storage<AllocatorStorage>
    {
      using base_type = ebo_storage<AllocatorStorage>;
      using allocator_type = typename AllocatorStorage::allocator_type;

      using alloc_traits   = allocator_traits<allocator_type>;
      using pointer_traits = std::pointer_traits<typename alloc_traits::pointer>;

      static_assert( !std::is_reference<T>::value, "Unable to delete reference type" );
      static_assert( !std::is_const<T>::value, "Unable to delete const type" );
      static_assert( !std::is_void<T>::value, "Unable to delete void type" );
      static_assert( is_allocator_storage<AllocatorStorage>::value,
                     "AllocatorStorage must satisfy AllocatorStorage requirements" );

      //-----------------------------------------------------------------------
      // Public Member Types
      //-----------------------------------------------------------------------
    public:

      using void_pointer    = typename alloc_traits::pointer;
      using pointer         = typename pointer_traits::template rebind<T>;
      using size_type       = typename alloc_traits::size_type;
      using difference_type = typename alloc_traits::difference_type;

      //-----------------------------------------------------------------------
      // Constructor
      //-----------------------------------------------------------------------
    public:

      polymorphic_allocator_deleter( AllocatorStorage storage,
                                     size_type size ) noexcept;

      polymorphic_allocator_deleter( polymorphic_allocator_deleter&& other ) noexcept = default;

      polymorphic_allocator_deleter( const polymorphic_allocator_deleter& other ) noexcept = default;

      // polymorphic conversions of arrays would be UB

      //-----------------------------------------------------------------------

      polymorphic_allocator_deleter&
        operator=( polymorphic_allocator_deleter&& other ) noexcept = default;

      polymorphic_allocator_deleter& operator=( const polymorphic_allocator_deleter& other ) noexcept = default;

      //-----------------------------------------------------------------------
      // Deallocation
      //-----------------------------------------------------------------------
    public:

      void operator()( pointer p );

      //-----------------------------------------------------------------------
      // Private Members
      //-----------------------------------------------------------------------
    private:

      size_type m_size;
    };
  } // namespace memory
} // namespace bit

#include "detail/polymorphic_allocator_deleter.inl"

#endif /* BIT_MEMORY_ADAPTERS_POLYMORPHIC_ALLOCATOR_DELETER_HPP */