//

// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)

//

// Distributed under the Boost Software License, Version 1.0. (See accompanying

// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

//

// Official repository: https://github.com/boostorg/json

//

#ifndef BOOST_JSON_DEFAULT_RESOURCE_HPP

#define BOOST_JSON_DEFAULT_RESOURCE_HPP

#include <boost/json/detail/config.hpp>

#include <new>

namespace boost {

namespace json {

namespace detail {

#ifdef _MSC_VER

#pragma warning(push)

#pragma warning(disable: 4251) // class needs to have dll-interface to be used by clients of class

#pragma warning(disable: 4275) // non dll-interface class used as base for dll-interface class

#endif

// A simple memory resource that uses operator new and delete.

class

    BOOST_SYMBOL_VISIBLE

    BOOST_JSON_CLASS_DECL

    default_resource final

    : public memory_resource

{

    union holder;

#ifndef BOOST_JSON_WEAK_CONSTINIT

# ifndef BOOST_JSON_NO_DESTROY

    static holder instance_;

# else

    BOOST_JSON_NO_DESTROY

    static default_resource instance_;

# endif

#endif

public:

    static

    memory_resource*

    get() noexcept

    {

    #ifdef BOOST_JSON_WEAK_CONSTINIT

        static default_resource instance_;

    #endif

        return reinterpret_cast<memory_resource*>(

            reinterpret_cast<std::uintptr_t*>(

                &instance_));

    }

    ~default_resource();

    void*

    do_allocate(

        std::size_t n,

        std::size_t) override;

    void

    do_deallocate(

        void* p,

        std::size_t,

        std::size_t) override;

    bool

    do_is_equal(

        memory_resource const& mr) const noexcept override;

};

#ifdef _MSC_VER

#pragma warning(pop)

#endif

union default_resource::

    holder

{

#ifndef BOOST_JSON_WEAK_CONSTINIT

    constexpr

#endif

    holder()

        : mr()

    {

    }

    ~holder()

    {

    }

    default_resource mr;

};

} // detail

} // namespace json

} // namespace boost

#endif