1// Copyright (c) 2001 Daniel C. Nuffer
2// Copyright (c) 2001-2011 Hartmut Kaiser
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_ITERATOR_INPUT_ITERATOR_POLICY_MAR_16_2007_1156AM)
8#define BOOST_SPIRIT_ITERATOR_INPUT_ITERATOR_POLICY_MAR_16_2007_1156AM
9
10#include <boost/spirit/home/support/iterators/multi_pass_fwd.hpp>
11#include <boost/spirit/home/support/iterators/detail/multi_pass.hpp>
12#include <boost/assert.hpp>
13#include <iterator> // for std::iterator_traits
14
15namespace boost { namespace spirit { namespace iterator_policies
16{
17 namespace input_iterator_is_valid_test_
18 {
19 ///////////////////////////////////////////////////////////////////////
20 template <typename Token>
21 inline bool token_is_valid(Token const& c)
22 {
23 return c ? true : false;
24 }
25 }
26
27 ///////////////////////////////////////////////////////////////////////////
28 // class input_iterator
29 // Implementation of the InputPolicy used by multi_pass
30 //
31 // The input_iterator encapsulates an input iterator of type T
32 ///////////////////////////////////////////////////////////////////////////
33 struct input_iterator
34 {
35 ///////////////////////////////////////////////////////////////////////
36 template <typename T>
37 class unique // : public detail::default_input_policy
38 {
39 private:
40 typedef
41 typename std::iterator_traits<T>::value_type
42 result_type;
43
44 public:
45 typedef
46 typename std::iterator_traits<T>::difference_type
47 difference_type;
48 typedef
49 typename std::iterator_traits<T>::difference_type
50 distance_type;
51 typedef
52 typename std::iterator_traits<T>::pointer
53 pointer;
54 typedef
55 typename std::iterator_traits<T>::reference
56 reference;
57 typedef result_type value_type;
58
59 protected:
60 unique() {}
61 explicit unique(T) {}
62
63 void swap(unique&) {}
64
65 public:
66 template <typename MultiPass>
67 static void destroy(MultiPass&) {}
68
69 template <typename MultiPass>
70 static typename MultiPass::reference get_input(MultiPass& mp)
71 {
72 return *mp.shared()->input_;
73 }
74
75 template <typename MultiPass>
76 static void advance_input(MultiPass& mp)
77 {
78 ++mp.shared()->input_;
79 }
80
81 // test, whether we reached the end of the underlying stream
82 template <typename MultiPass>
83 static bool input_at_eof(MultiPass const& mp)
84 {
85 static T const end_iter;
86 return mp.shared()->input_ == end_iter;
87 }
88
89 template <typename MultiPass>
90 static bool input_is_valid(MultiPass const&, value_type const& t)
91 {
92 using namespace input_iterator_is_valid_test_;
93 return token_is_valid(t);
94 }
95
96 // no unique data elements
97 };
98
99 ///////////////////////////////////////////////////////////////////////
100 template <typename T>
101 struct shared
102 {
103 explicit shared(T const& input) : input_(input) {}
104
105 T input_;
106 };
107 };
108
109}}}
110
111#endif
112

source code of boost/libs/spirit/include/boost/spirit/home/support/iterators/detail/input_iterator_policy.hpp