1/*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3
4 Distributed under the Boost Software License, Version 1.0. (See accompanying
5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6==============================================================================*/
7#if !defined(BOOST_SPIRIT_REFERENCE_OCTOBER_31_2008_1218AM)
8#define BOOST_SPIRIT_REFERENCE_OCTOBER_31_2008_1218AM
9
10#if defined(_MSC_VER)
11#pragma once
12#endif
13
14#include <boost/spirit/home/qi/meta_compiler.hpp>
15#include <boost/spirit/home/qi/parser.hpp>
16#include <boost/spirit/home/support/info.hpp>
17#include <boost/spirit/home/support/handles_container.hpp>
18#include <boost/type_traits/remove_const.hpp>
19#include <boost/ref.hpp>
20
21namespace boost { namespace spirit { namespace qi
22{
23 ///////////////////////////////////////////////////////////////////////////
24 // reference is a parser that references another parser (its Subject)
25 ///////////////////////////////////////////////////////////////////////////
26 template <typename Subject>
27 struct reference : parser<reference<Subject> >
28 {
29 typedef Subject subject_type;
30
31 reference(Subject& subject)
32 : ref(subject) {}
33
34 template <typename Context, typename Iterator>
35 struct attribute : Subject::template attribute<Context, Iterator> {};
36
37 template <typename Iterator, typename Context
38 , typename Skipper, typename Attribute>
39 bool parse(Iterator& first, Iterator const& last
40 , Context& context, Skipper const& skipper
41 , Attribute& attr_) const
42 {
43 return ref.get().parse(first, last, context, skipper, attr_);
44 }
45
46 template <typename Context>
47 info what(Context& context) const
48 {
49 // the reference is transparent (does not add any info)
50 return ref.get().what(context);
51 }
52
53 boost::reference_wrapper<Subject> ref;
54 };
55}}}
56
57namespace boost { namespace spirit { namespace traits
58{
59 ///////////////////////////////////////////////////////////////////////////
60 template <typename Subject, typename Attribute, typename Context
61 , typename Iterator>
62 struct handles_container<qi::reference<Subject>, Attribute, Context
63 , Iterator>
64 : handles_container<typename remove_const<Subject>::type
65 , Attribute, Context, Iterator>
66 {};
67}}}
68
69#endif
70

source code of boost/libs/spirit/include/boost/spirit/home/qi/reference.hpp