1 2 #ifndef BOOST_MPL_SWITCH_HPP_INCLUDED 3 #define BOOST_MPL_SWITCH_HPP_INCLUDED 4 5 // Copyright Aleksey Gurtovoy 2003-2004 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 // $Id$ 14 // $Date$ 15 // $Revision$ 16 17 #include <boost/mpl/find_if.hpp> 18 #include <boost/mpl/deref.hpp> 19 #include <boost/mpl/lambda.hpp> 20 #include <boost/mpl/apply.hpp> 21 #include <boost/mpl/pair.hpp> 22 #include <boost/mpl/aux_/na_spec.hpp> 23 #include <boost/mpl/aux_/lambda_support.hpp> 24 25 namespace boost { namespace mpl { 26 27 template< 28 typename BOOST_MPL_AUX_NA_PARAM(Body) 29 , typename BOOST_MPL_AUX_NA_PARAM(T) 30 > 31 struct switch_ 32 { 33 typedef typename find_if< 34 Body 35 , apply1< lambda< first<_1> >, T > 36 >::type iter_; 37 38 typedef typename deref<iter_>::type pair_; 39 typedef typename lambda< typename second<pair_>::type >::type f_; 40 typedef typename apply1<f_,T>::type type; 41 42 BOOST_MPL_AUX_LAMBDA_SUPPORT(2,switch_,(Body,T)) 43 }; 44 45 BOOST_MPL_AUX_NA_SPEC(2, switch_) 46 47 }} 48 49 #endif // BOOST_MPL_SWITCH_HPP_INCLUDED 50