ext-boost/boost/smart_ptr/detail/sp_convertible.hpp
2015-08-16 20:45:50 -03:00

93 lines
2.1 KiB
C++

#ifndef BOOST_SMART_PTR_DETAIL_SP_CONVERTIBLE_HPP_INCLUDED
#define BOOST_SMART_PTR_DETAIL_SP_CONVERTIBLE_HPP_INCLUDED
// MS compatible compilers support #pragma once
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
// detail/sp_convertible.hpp
//
// Copyright 2008 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 <boost/config.hpp>
#include <cstddef>
#if !defined( BOOST_SP_NO_SP_CONVERTIBLE ) && defined( BOOST_NO_SFINAE )
# define BOOST_SP_NO_SP_CONVERTIBLE
#endif
#if !defined( BOOST_SP_NO_SP_CONVERTIBLE ) && defined( __GNUC__ ) && ( __GNUC__ * 100 + __GNUC_MINOR__ < 303 )
# define BOOST_SP_NO_SP_CONVERTIBLE
#endif
#if !defined( BOOST_SP_NO_SP_CONVERTIBLE ) && defined( __BORLANDC__ ) && ( __BORLANDC__ < 0x630 )
# define BOOST_SP_NO_SP_CONVERTIBLE
#endif
#if !defined( BOOST_SP_NO_SP_CONVERTIBLE )
namespace boost
{
namespace detail
{
template< class Y, class T > struct sp_convertible
{
typedef char (&yes) [1];
typedef char (&no) [2];
static yes f( T* );
static no f( ... );
enum _vt { value = sizeof( (f)( static_cast<Y*>(0) ) ) == sizeof(yes) };
};
template< class Y, class T > struct sp_convertible< Y, T[] >
{
enum _vt { value = false };
};
template< class Y, class T > struct sp_convertible< Y[], T[] >
{
enum _vt { value = sp_convertible< Y[1], T[1] >::value };
};
template< class Y, std::size_t N, class T > struct sp_convertible< Y[N], T[] >
{
enum _vt { value = sp_convertible< Y[1], T[1] >::value };
};
struct sp_empty
{
};
template< bool > struct sp_enable_if_convertible_impl;
template<> struct sp_enable_if_convertible_impl<true>
{
typedef sp_empty type;
};
template<> struct sp_enable_if_convertible_impl<false>
{
};
template< class Y, class T > struct sp_enable_if_convertible: public sp_enable_if_convertible_impl< sp_convertible< Y, T >::value >
{
};
} // namespace detail
} // namespace boost
#endif // !defined( BOOST_SP_NO_SP_CONVERTIBLE )
#endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_CONVERTIBLE_HPP_INCLUDED