boost/xpressive/detail/static/transforms/as_marker.hpp
///////////////////////////////////////////////////////////////////////////////
// as_marker.hpp
//
// Copyright 2008 Eric Niebler. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_XPRESSIVE_DETAIL_STATIC_TRANSFORMS_AS_MARKER_HPP_EAN_04_01_2007
#define BOOST_XPRESSIVE_DETAIL_STATIC_TRANSFORMS_AS_MARKER_HPP_EAN_04_01_2007
// MS compatible compilers support #pragma once
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/static/static.hpp>
#include <boost/xpressive/proto/proto.hpp>
namespace boost { namespace xpressive { namespace grammar_detail
{
///////////////////////////////////////////////////////////////////////////////
// as_marker
// Insert mark tags before and after the expression
struct as_marker : proto::callable
{
template<typename Sig> struct result {};
template<typename This, typename Expr, typename State, typename Visitor>
struct result<This(Expr, State, Visitor)>
{
typedef
typename shift_right<
terminal<detail::mark_begin_matcher>::type
, typename shift_right<
typename proto::result_of::right<Expr>::type
, terminal<detail::mark_end_matcher>::type
>::type
>::type
type;
};
template<typename Expr, typename State, typename Visitor>
typename result<void(Expr, State, Visitor)>::type
operator ()(Expr const &expr, State const &, Visitor &) const
{
int mark_nbr = detail::get_mark_number(proto::left(expr));
detail::mark_begin_matcher begin(mark_nbr);
detail::mark_end_matcher end(mark_nbr);
typename result<void(Expr, State, Visitor)>::type that
= {{begin}, {proto::right(expr), {end}}};
return that;
}
};
}}}
#endif