mpl/aux_/yes_no.hpp

0001
0002 #ifndef BOOST_MPL_AUX_YES_NO_HPP_INCLUDED
0003 #define BOOST_MPL_AUX_YES_NO_HPP_INCLUDED
0004
0005 // Copyright Aleksey Gurtovoy 2000-2004
0006 //
0007 // Distributed under the Boost Software License, Version 1.0.
0008 // (See accompanying file LICENSE_1_0.txt or copy at
0009 // http://www.boost.org/LICENSE_1_0.txt)
0010 //
0011 // See http://www.boost.org/libs/mpl for documentation.
0012
0013 // $Id$
0014 // $Date$
0015 // $Revision$
0016
0017 #include <boost/mpl/aux_/nttp_decl.hpp>
0018 #include <boost/mpl/aux_/config/arrays.hpp>
0019 #include <boost/mpl/aux_/config/msvc.hpp>
0020 #include <boost/mpl/aux_/config/workaround.hpp>
0021 #include <cstddef>
0022
0023
0024 namespace boost { namespace mpl { namespace aux {
0025
0026 typedef char (&no_tag)[1];
0027 typedef char (&yes_tag)[2];
0028
0029 template< bool C_ > struct yes_no_tag
0030 {
0031     typedef no_tag type;
0032 };
0033
0034 template<> struct yes_no_tag<true>
0035 {
0036     typedef yes_tag type;
0037 };
0038
0039
0040 template< BOOST_MPL_AUX_NTTP_DECL(std::size_t, n) > struct weighted_tag
0041 {
0042 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
0043     typedef char (&type)[n];
0044 #else
0045     char buf[n];
0046     typedef weighted_tag type;
0047 #endif
0048 };
0049
0050 #if defined(BOOST_MPL_CFG_NO_DEPENDENT_ARRAY_TYPES)
0051 template<> struct weighted_tag<0>
0052 {
0053     typedef char (&type)[1];
0054 };
0055 #endif
0056
0057 }}}
0058
0059 #endif // BOOST_MPL_AUX_YES_NO_HPP_INCLUDED