/Src/Dependencies/Boost/boost/mpl/tag.hpp

 1
 2#ifndef BOOST_MPL_TAG_HPP_INCLUDED
 3#define BOOST_MPL_TAG_HPP_INCLUDED
 4
 5// Copyright Aleksey Gurtovoy 2004
 6//
 7// Distributed under the Boost Software License, Version 1.0. 
 8// (See accompanying file LICENSE_1_0.txt or copy at 
 9// http://www.boost.org/LICENSE_1_0.txt)
10//
11// See http://www.boost.org/libs/mpl for documentation.
12
13// $Id: tag.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
14// $Date: 2008-10-11 17:19:02 +1100 (Sat, 11 Oct 2008) $
15// $Revision: 49267 $
16
17#include <boost/mpl/eval_if.hpp>
18#include <boost/mpl/void.hpp>
19#include <boost/mpl/aux_/has_tag.hpp>
20#include <boost/mpl/aux_/config/eti.hpp>
21
22namespace boost { namespace mpl {
23
24namespace aux {
25template< typename T > struct tag_impl
26{
27    typedef typename T::tag type;
28};
29}
30
31template< typename T, typename Default = void_ > struct tag
32#if !defined(BOOST_MPL_CFG_MSVC_ETI_BUG)
33    : if_< 
34          aux::has_tag<T>
35        , aux::tag_impl<T>
36        , Default
37        >::type
38{
39#else
40{
41    typedef typename eval_if< 
42          aux::has_tag<T>
43        , aux::tag_impl<T>
44        , Default
45        >::type type;
46
47#endif
48};
49
50}}
51
52#endif // BOOST_MPL_TAG_HPP_INCLUDED