#ifndef BOOST_SMART_PTR_DETAIL_SHARED_PTR_NMT_HPP_INCLUDED

#define BOOST_SMART_PTR_DETAIL_SHARED_PTR_NMT_HPP_INCLUDED

//

//  detail/shared_ptr_nmt.hpp - shared_ptr.hpp without member templates

//

//  (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.

//  Copyright (c) 2001, 2002 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)

//

//  See http://www.boost.org/libs/smart_ptr/shared_ptr.htm for documentation.

//

#include <boost/assert.hpp>

#include <boost/checked_delete.hpp>

#include <boost/throw_exception.hpp>

#include <boost/smart_ptr/detail/atomic_count.hpp>

#ifndef BOOST_NO_AUTO_PTR

# include <memory>          // for std::auto_ptr

#endif

#include <algorithm>        // for std::swap

#include <functional>       // for std::less

#include <new>              // for std::bad_alloc

namespace boost

{

template<class T> class shared_ptr

{

private:

    typedef detail::atomic_count count_type;

public:

    typedef T element_type;

    typedef T value_type;

    explicit shared_ptr(T * p = 0): px(p)

    {

#ifndef BOOST_NO_EXCEPTIONS

        try  // prevent leak if new throws

        {

            pn = new count_type(1);

        }

        catch(...)

        {

            boost::checked_delete(p);

            throw;

        }

#else

        pn = new count_type(1);

        if(pn == 0)

        {

            boost::checked_delete(p);

            boost::throw_exception(std::bad_alloc());

        }

#endif

    }

    ~shared_ptr()

    {

        if(--*pn == 0)

        {

            boost::checked_delete(px);

            delete pn;

        }

    }

    shared_ptr(shared_ptr const & r): px(r.px)  // never throws

    {

        pn = r.pn;

        ++*pn;

    }

    shared_ptr & operator=(shared_ptr const & r)

    {

        shared_ptr(r).swap(*this);

        return *this;

    }

#ifndef BOOST_NO_AUTO_PTR

    explicit shared_ptr(std::auto_ptr<T> & r)

    { 

        pn = new count_type(1); // may throw

        px = r.release(); // fix: moved here to stop leak if new throws

    } 

    shared_ptr & operator=(std::auto_ptr<T> & r)

    {

        shared_ptr(r).swap(*this);

        return *this;

    }

#endif

    void reset(T * p = 0)

    {

        BOOST_ASSERT(p == 0 || p != px);

        shared_ptr(p).swap(*this);

    }

    T & operator*() const  // never throws

    {

        BOOST_ASSERT(px != 0);

        return *px;

    }

    T * operator->() const  // never throws

    {

        BOOST_ASSERT(px != 0);

        return px;

    }

    T * get() const  // never throws

    {

        return px;

    }

    long use_count() const  // never throws

    {

        return *pn;

    }

    bool unique() const  // never throws

    {

        return *pn == 1;

    }

    void swap(shared_ptr<T> & other)  // never throws

    {

        std::swap(px, other.px);

        std::swap(pn, other.pn);

    }

private:

    T * px;            // contained pointer

    count_type * pn;   // ptr to reference counter

};

template<class T, class U> inline bool operator==(shared_ptr<T> const & a, shared_ptr<U> const & b)

{

    return a.get() == b.get();

}

template<class T, class U> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<U> const & b)

{

    return a.get() != b.get();

}

template<class T> inline bool operator<(shared_ptr<T> const & a, shared_ptr<T> const & b)

{

    return std::less<T*>()(a.get(), b.get());

}

template<class T> void swap(shared_ptr<T> & a, shared_ptr<T> & b)

{

    a.swap(b);

}

// get_pointer() enables boost::mem_fn to recognize shared_ptr

template<class T> inline T * get_pointer(shared_ptr<T> const & p)

{

    return p.get();

}

} // namespace boost

#endif  // #ifndef BOOST_SMART_PTR_DETAIL_SHARED_PTR_NMT_HPP_INCLUDED