1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
// Copyright 2009 (C) Dean Michael Berris <me@deanberris.com>
// 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_FUNCTION_INPUT_ITERATOR
#define BOOST_FUNCTION_INPUT_ITERATOR
#include <boost/mpl/if.hpp>
#include <boost/function_types/is_function_pointer.hpp>
#include <boost/function_types/is_function_reference.hpp>
#include <boost/function_types/result_type.hpp>
#include <boost/iterator/iterator_facade.hpp>
namespace boost {
namespace impl {
template <class Function, class Input>
class function_input_iterator
: public iterator_facade<
function_input_iterator<Function, Input>,
typename Function::result_type,
single_pass_traversal_tag,
typename Function::result_type const &
>
{
public:
function_input_iterator() {}
function_input_iterator(Function & f_, Input state_ = Input())
: f(&f_), state(state_), value((*f)()) {}
void increment() {
value = (*f)();
++state;
}
typename Function::result_type const &
dereference() const {
return value;
}
bool equal(function_input_iterator const & other) const {
return f == other.f && state == other.state;
}
private:
Function * f;
Input state;
typename Function::result_type value;
};
template <class Function, class Input>
class function_pointer_input_iterator
: public iterator_facade<
function_pointer_input_iterator<Function, Input>,
typename function_types::result_type<Function>::type,
single_pass_traversal_tag,
typename function_types::result_type<Function>::type const &
>
{
public:
function_pointer_input_iterator() {}
function_pointer_input_iterator(Function &f_, Input state_ = Input())
: f(f_), state(state_), value((*f)())
{}
void increment() {
value = (*f)();
++state;
}
typename function_types::result_type<Function>::type const &
dereference() const {
return value;
}
bool equal(function_pointer_input_iterator const & other) const {
return f == other.f && state == other.state;
}
private:
Function f;
Input state;
typename function_types::result_type<Function>::type value;
};
template <class Function, class Input>
class function_reference_input_iterator
: public function_pointer_input_iterator<Function*,Input>
{
public:
function_reference_input_iterator(Function & f_, Input state_ = Input())
: function_pointer_input_iterator<Function*,Input>(&f_, state_)
{}
};
} // namespace impl
template <class Function, class Input>
class function_input_iterator
: public mpl::if_<
function_types::is_function_pointer<Function>,
impl::function_pointer_input_iterator<Function,Input>,
typename mpl::if_<
function_types::is_function_reference<Function>,
impl::function_reference_input_iterator<Function,Input>,
impl::function_input_iterator<Function,Input>
>::type
>::type
{
typedef typename mpl::if_<
function_types::is_function_pointer<Function>,
impl::function_pointer_input_iterator<Function,Input>,
typename mpl::if_<
function_types::is_function_reference<Function>,
impl::function_reference_input_iterator<Function,Input>,
impl::function_input_iterator<Function,Input>
>::type
>::type base_type;
public:
function_input_iterator(Function & f, Input i)
: base_type(f, i) {}
};
template <class Function, class Input>
inline function_input_iterator<Function, Input>
make_function_input_iterator(Function & f, Input state) {
typedef function_input_iterator<Function, Input> result_t;
return result_t(f, state);
}
template <class Function, class Input>
inline function_input_iterator<Function*, Input>
make_function_input_iterator(Function * f, Input state) {
typedef function_input_iterator<Function*, Input> result_t;
return result_t(f, state);
}
struct infinite {
infinite & operator++() { return *this; }
infinite & operator++(int) { return *this; }
bool operator==(infinite &) const { return false; };
bool operator==(infinite const &) const { return false; };
};
}
#endif
|
