operator_bool.hpp

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//  This header intentionally has no include guards.
//
//  Copyright (c) 2001-2009, 2012 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( BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS ) && !defined( BOOST_NO_CXX11_NULLPTR )\
    && !(defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x5130))
 
    explicit operator bool () const BOOST_NOEXCEPT
    {
        return px != 0;
    }
 
#elif ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, < 0x570) ) || defined(__CINT__)
 
    operator bool () const BOOST_NOEXCEPT
    {
        return px != 0;
    }
 
#elif defined( _MANAGED )
 
    static void unspecified_bool( this_type*** )
    {
    }
 
    typedef void (*unspecified_bool_type)( this_type*** );
 
    operator unspecified_bool_type() const BOOST_NOEXCEPT
    {
        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 element_type * (this_type::*unspecified_bool_type)() const;
 
    operator unspecified_bool_type() const BOOST_NOEXCEPT
    {
        return px == 0? 0: &this_type::get;
    }
 
#else
 
    typedef element_type * this_type::*unspecified_bool_type;
 
    operator unspecified_bool_type() const BOOST_NOEXCEPT
    {
        return px == 0? 0: &this_type::px;
    }
 
#endif
 
    // operator! is redundant, but some compilers need it
    bool operator! () const BOOST_NOEXCEPT
    {
        return px == 0;
    }