support/auxiliary/attr_cast.hpp

0001 //  Copyright (c) 2001-2011 Hartmut Kaiser
0002 //
0003 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
0004 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0005
0006 #ifndef BOOST_SPIRIT_SUPPORT_AUXILIARY_ATTR_CAST_HPP
0007 #define BOOST_SPIRIT_SUPPORT_AUXILIARY_ATTR_CAST_HPP
0008
0009 #if defined(_MSC_VER)
0010 #pragma once
0011 #endif
0012
0013 #include <boost/spirit/home/support/common_terminals.hpp>
0014 #include <boost/spirit/home/support/attributes.hpp>
0015 #include <boost/core/enable_if.hpp>
0016 #include <boost/proto/traits.hpp>
0017
0018 namespace boost { namespace spirit
0019 {
0020     ///////////////////////////////////////////////////////////////////////////
0021     // This one is the function that the user can call directly in order
0022     // to create a customized attr_cast component
0023     template <typename Expr>
0024     typename enable_if<proto::is_expr<Expr>
0025       , stateful_tag_type<Expr, tag::attr_cast> >::type
0026     attr_cast(Expr const& expr)
0027     {
0028         return stateful_tag_type<Expr, tag::attr_cast>(expr);
0029     }
0030
0031     template <typename Exposed, typename Expr>
0032     typename enable_if<proto::is_expr<Expr>
0033       , stateful_tag_type<Expr, tag::attr_cast, Exposed> >::type
0034     attr_cast(Expr const& expr)
0035     {
0036         return stateful_tag_type<Expr, tag::attr_cast, Exposed>(expr);
0037     }
0038
0039     template <typename Exposed, typename Transformed, typename Expr>
0040     typename enable_if<proto::is_expr<Expr>
0041       , stateful_tag_type<Expr, tag::attr_cast, Exposed, Transformed> >::type
0042     attr_cast(Expr const& expr)
0043     {
0044         return stateful_tag_type<Expr, tag::attr_cast, Exposed, Transformed>(expr);
0045     }
0046 }}
0047
0048 #endif