//  This header intentionally has no include guards.

//

//  Copyright (c) 2001-2009 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

#if ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, < 0x570) ) || defined(__CINT__)

    operator bool () const

    {

        return px != 0;

    }

#elif defined( _MANAGED )

    static void unspecified_bool( this_type*** )

    {

    }

    typedef void (*unspecified_bool_type)( this_type*** );

    operator unspecified_bool_type() const // never throws

    {

        return px == 0? 0: unspecified_bool;

    }

#elif \

    ( defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, < 0x3200) ) || \

    ( defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 304) ) || \

    ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590) )

    typedef T * (this_type::*unspecified_bool_type)() const;

    operator unspecified_bool_type() const // never throws

    {

        return px == 0? 0: &this_type::get;

    }

#else

    typedef T * this_type::*unspecified_bool_type;

    operator unspecified_bool_type() const // never throws

    {

        return px == 0? 0: &this_type::px;

    }

#endif

    // operator! is redundant, but some compilers need it

    bool operator! () const // never throws

    {

        return px == 0;

    }