#ifndef BOOST_DETAIL_SP_COUNTED_BASE_NT_HPP_INCLUDED

#define BOOST_DETAIL_SP_COUNTED_BASE_NT_HPP_INCLUDED

// MS compatible compilers support #pragma once

#if defined(_MSC_VER) && (_MSC_VER >= 1020)

# pragma once

#endif

//

//  detail/sp_counted_base_nt.hpp

//

//  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.

//  Copyright 2004-2005 Peter Dimov

//

// 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)

//

#include <typeinfo>

namespace boost

{

namespace detail

{

class sp_counted_base

{

private:

    sp_counted_base( sp_counted_base const & );

    sp_counted_base & operator= ( sp_counted_base const & );

    long use_count_;        // #shared

    long weak_count_;       // #weak + (#shared != 0)

public:

    sp_counted_base(): use_count_( 1 ), weak_count_( 1 )

    {

    }

    virtual ~sp_counted_base() // nothrow

    {

    }

    // dispose() is called when use_count_ drops to zero, to release

    // the resources managed by *this.

    virtual void dispose() = 0; // nothrow

    // destroy() is called when weak_count_ drops to zero.

    virtual void destroy() // nothrow

    {

        delete this;

    }

    virtual void * get_deleter( std::type_info const & ti ) = 0;

    void add_ref_copy()

    {

        ++use_count_;

    }

    bool add_ref_lock() // true on success

    {

        if( use_count_ == 0 ) return false;

        ++use_count_;

        return true;

    }

    void release() // nothrow

    {

        if( --use_count_ == 0 )

        {

            dispose();

            weak_release();

        }

    }

    void weak_add_ref() // nothrow

    {

        ++weak_count_;

    }

    void weak_release() // nothrow

    {

        if( --weak_count_ == 0 )

        {

            destroy();

        }

    }

    long use_count() const // nothrow

    {

        return use_count_;

    }

};

} // namespace detail

} // namespace boost

#endif  // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_NT_HPP_INCLUDED