boost/mpl/switch.hpp

0001
0002 #ifndef BOOST_MPL_SWITCH_HPP_INCLUDED
0003 #define BOOST_MPL_SWITCH_HPP_INCLUDED
0004
0005 // Copyright Aleksey Gurtovoy 2003-2004
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/find_if.hpp>
0018 #include <boost/mpl/deref.hpp>
0019 #include <boost/mpl/lambda.hpp>
0020 #include <boost/mpl/apply.hpp>
0021 #include <boost/mpl/pair.hpp>
0022 #include <boost/mpl/aux_/na_spec.hpp>
0023 #include <boost/mpl/aux_/lambda_support.hpp>
0024
0025 namespace boost { namespace mpl {
0026
0027 template<
0028       typename BOOST_MPL_AUX_NA_PARAM(Body)
0029     , typename BOOST_MPL_AUX_NA_PARAM(T)
0030     >
0031 struct switch_
0032 {
0033     typedef typename find_if<
0034           Body
0035         , apply1< lambda< first<_1> >, T >
0036         >::type iter_;
0037
0038     typedef typename deref<iter_>::type pair_;
0039     typedef typename lambda< typename second<pair_>::type >::type f_;
0040     typedef typename apply1<f_,T>::type type;
0041
0042     BOOST_MPL_AUX_LAMBDA_SUPPORT(2,switch_,(Body,T))
0043 };
0044
0045 BOOST_MPL_AUX_NA_SPEC(2, switch_)
0046
0047 }}
0048
0049 #endif // BOOST_MPL_SWITCH_HPP_INCLUDED