native_allocator.h

// Description: Native allocator
// Detail: An allocator wrapper for new and delete

#ifndef PASTELSYS_NATIVE_ALLOCATOR_H
#define PASTELSYS_NATIVE_ALLOCATOR_H

#include "pastel/sys/mytypes.h"

#include <boost/operators.hpp>

namespace Pastel
{

    //! A uniform allocator wrapper for new and delete.

    class NativeAllocator
        : boost::equality_comparable<
        NativeAllocator
        , boost::less_than_comparable<
        NativeAllocator
        > >
    {
    public:
        //! Constructs an allocator with the given 'unitSize'.
        /*!
       Time complexity: constant
       Exception safety: nothrow

       The parameter 'isPodDataIgnored' has no meaning with
       this allocator.
       */
        explicit NativeAllocator(
            integer unitSize,
            bool isPodDataIgnored = false);

        //! Destructs the allocator.
        /*!
       Time complexity: constant
       Exception safety: nothrow
       */
        ~NativeAllocator();

        //! Compares two allocators.
        /*!
       Time complexity: constant
       Exception safety: nothrow

       The comparison is done by memory addresses.
       */
        bool operator==(const NativeAllocator& that) const;

        //! Compares two allocators.
        /*!
       Time complexity: constant
       Exception safety: nothrow

       The comparison is done by memory addresses.
       */
        bool operator<(const NativeAllocator& that) const;

        //! Swaps two allocators.
        /*!
       Time complexity: constant
       Exception safety: nothrow
       */
        void swap(NativeAllocator& that);

        //! A no-op.
        /*!
       Time complexity: constant
       Exception safety: nothrow
       */
        void clear();

        //! Returns the unit size.
        /*!
       Time complexity: constant
       Exception safety: nothrow
       */
        integer unitSize() const;

        //! Returns the amount of requested memory.
        /*!
       Time complexity: constant
       Exception safety: nothrow
       */
        integer size() const;

        //! Returns the actual amount of allocated memory.
        /*!
       Time complexity: constant
       Exception safety: nothrow
       */
        integer capacity() const;

        //! Allocates unitSize-sized memory area.
        /*!
       Time complexity: constant
       Exception safety: strong
       */
        void* allocate();

        //! Deallocates a previously allocated area.
        /*!
       Time complexity: constant
       Exception safety: nothrow
       */
        void deallocate(const void* memAddress);

    private:
        NativeAllocator(const NativeAllocator& that) = delete;
        NativeAllocator& operator=(const NativeAllocator& that) = delete;

        integer unitSize_;
        integer unitsAllocated_;
    };

    void swap(NativeAllocator& left, NativeAllocator& right);

}

#include "pastel/sys/allocator/native_allocator.hpp"

#endif