Chris@16
|
1 // (C) Copyright David Abrahams 2002.
|
Chris@16
|
2 // (C) Copyright Jeremy Siek 2002.
|
Chris@16
|
3 // (C) Copyright Thomas Witt 2002.
|
Chris@16
|
4 // Distributed under the Boost Software License, Version 1.0. (See
|
Chris@16
|
5 // accompanying file LICENSE_1_0.txt or copy at
|
Chris@16
|
6 // http://www.boost.org/LICENSE_1_0.txt)
|
Chris@16
|
7 #ifndef BOOST_TRANSFORM_ITERATOR_23022003THW_HPP
|
Chris@16
|
8 #define BOOST_TRANSFORM_ITERATOR_23022003THW_HPP
|
Chris@16
|
9
|
Chris@16
|
10 #include <boost/iterator.hpp>
|
Chris@16
|
11 #include <boost/iterator/detail/enable_if.hpp>
|
Chris@16
|
12 #include <boost/iterator/iterator_adaptor.hpp>
|
Chris@16
|
13 #include <boost/iterator/iterator_categories.hpp>
|
Chris@16
|
14 #include <boost/mpl/not.hpp>
|
Chris@16
|
15 #include <boost/mpl/bool.hpp>
|
Chris@16
|
16 #include <boost/type_traits/function_traits.hpp>
|
Chris@16
|
17 #include <boost/type_traits/is_const.hpp>
|
Chris@16
|
18 #include <boost/type_traits/is_class.hpp>
|
Chris@16
|
19 #include <boost/type_traits/is_function.hpp>
|
Chris@16
|
20 #include <boost/type_traits/is_reference.hpp>
|
Chris@16
|
21 #include <boost/type_traits/remove_const.hpp>
|
Chris@16
|
22 #include <boost/type_traits/remove_reference.hpp>
|
Chris@16
|
23 #include <boost/utility/result_of.hpp>
|
Chris@16
|
24
|
Chris@16
|
25
|
Chris@16
|
26 #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1310))
|
Chris@16
|
27 # include <boost/type_traits/is_base_and_derived.hpp>
|
Chris@16
|
28
|
Chris@101
|
29 #endif
|
Chris@16
|
30 #include <boost/iterator/detail/config_def.hpp>
|
Chris@16
|
31
|
Chris@16
|
32
|
Chris@101
|
33 namespace boost {
|
Chris@101
|
34 namespace iterators {
|
Chris@101
|
35
|
Chris@16
|
36 template <class UnaryFunction, class Iterator, class Reference = use_default, class Value = use_default>
|
Chris@16
|
37 class transform_iterator;
|
Chris@16
|
38
|
Chris@101
|
39 namespace detail
|
Chris@16
|
40 {
|
Chris@16
|
41 // Compute the iterator_adaptor instantiation to be used for transform_iterator
|
Chris@16
|
42 template <class UnaryFunc, class Iterator, class Reference, class Value>
|
Chris@16
|
43 struct transform_iterator_base
|
Chris@16
|
44 {
|
Chris@16
|
45 private:
|
Chris@16
|
46 // By default, dereferencing the iterator yields the same as
|
Chris@16
|
47 // the function.
|
Chris@16
|
48 typedef typename ia_dflt_help<
|
Chris@16
|
49 Reference
|
Chris@16
|
50 , result_of<const UnaryFunc(typename std::iterator_traits<Iterator>::reference)>
|
Chris@16
|
51 >::type reference;
|
Chris@16
|
52
|
Chris@16
|
53 // To get the default for Value: remove any reference on the
|
Chris@16
|
54 // result type, but retain any constness to signal
|
Chris@16
|
55 // non-writability. Note that if we adopt Thomas' suggestion
|
Chris@16
|
56 // to key non-writability *only* on the Reference argument,
|
Chris@16
|
57 // we'd need to strip constness here as well.
|
Chris@16
|
58 typedef typename ia_dflt_help<
|
Chris@16
|
59 Value
|
Chris@16
|
60 , remove_reference<reference>
|
Chris@16
|
61 >::type cv_value_type;
|
Chris@16
|
62
|
Chris@16
|
63 public:
|
Chris@16
|
64 typedef iterator_adaptor<
|
Chris@16
|
65 transform_iterator<UnaryFunc, Iterator, Reference, Value>
|
Chris@16
|
66 , Iterator
|
Chris@16
|
67 , cv_value_type
|
Chris@16
|
68 , use_default // Leave the traversal category alone
|
Chris@16
|
69 , reference
|
Chris@16
|
70 > type;
|
Chris@16
|
71 };
|
Chris@16
|
72 }
|
Chris@16
|
73
|
Chris@16
|
74 template <class UnaryFunc, class Iterator, class Reference, class Value>
|
Chris@16
|
75 class transform_iterator
|
Chris@101
|
76 : public boost::iterators::detail::transform_iterator_base<UnaryFunc, Iterator, Reference, Value>::type
|
Chris@16
|
77 {
|
Chris@16
|
78 typedef typename
|
Chris@101
|
79 boost::iterators::detail::transform_iterator_base<UnaryFunc, Iterator, Reference, Value>::type
|
Chris@16
|
80 super_t;
|
Chris@16
|
81
|
Chris@16
|
82 friend class iterator_core_access;
|
Chris@16
|
83
|
Chris@16
|
84 public:
|
Chris@16
|
85 transform_iterator() { }
|
Chris@16
|
86
|
Chris@16
|
87 transform_iterator(Iterator const& x, UnaryFunc f)
|
Chris@16
|
88 : super_t(x), m_f(f) { }
|
Chris@16
|
89
|
Chris@16
|
90 explicit transform_iterator(Iterator const& x)
|
Chris@16
|
91 : super_t(x)
|
Chris@16
|
92 {
|
Chris@16
|
93 // Pro8 is a little too aggressive about instantiating the
|
Chris@16
|
94 // body of this function.
|
Chris@16
|
95 #if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
|
Chris@16
|
96 // don't provide this constructor if UnaryFunc is a
|
Chris@16
|
97 // function pointer type, since it will be 0. Too dangerous.
|
Chris@16
|
98 BOOST_STATIC_ASSERT(is_class<UnaryFunc>::value);
|
Chris@101
|
99 #endif
|
Chris@16
|
100 }
|
Chris@16
|
101
|
Chris@16
|
102 template <
|
Chris@16
|
103 class OtherUnaryFunction
|
Chris@16
|
104 , class OtherIterator
|
Chris@16
|
105 , class OtherReference
|
Chris@16
|
106 , class OtherValue>
|
Chris@16
|
107 transform_iterator(
|
Chris@16
|
108 transform_iterator<OtherUnaryFunction, OtherIterator, OtherReference, OtherValue> const& t
|
Chris@16
|
109 , typename enable_if_convertible<OtherIterator, Iterator>::type* = 0
|
Chris@16
|
110 #if !BOOST_WORKAROUND(BOOST_MSVC, == 1310)
|
Chris@16
|
111 , typename enable_if_convertible<OtherUnaryFunction, UnaryFunc>::type* = 0
|
Chris@101
|
112 #endif
|
Chris@16
|
113 )
|
Chris@16
|
114 : super_t(t.base()), m_f(t.functor())
|
Chris@16
|
115 {}
|
Chris@16
|
116
|
Chris@16
|
117 UnaryFunc functor() const
|
Chris@16
|
118 { return m_f; }
|
Chris@16
|
119
|
Chris@16
|
120 private:
|
Chris@16
|
121 typename super_t::reference dereference() const
|
Chris@16
|
122 { return m_f(*this->base()); }
|
Chris@16
|
123
|
Chris@16
|
124 // Probably should be the initial base class so it can be
|
Chris@16
|
125 // optimized away via EBO if it is an empty class.
|
Chris@16
|
126 UnaryFunc m_f;
|
Chris@16
|
127 };
|
Chris@16
|
128
|
Chris@16
|
129 template <class UnaryFunc, class Iterator>
|
Chris@101
|
130 inline transform_iterator<UnaryFunc, Iterator>
|
Chris@16
|
131 make_transform_iterator(Iterator it, UnaryFunc fun)
|
Chris@16
|
132 {
|
Chris@16
|
133 return transform_iterator<UnaryFunc, Iterator>(it, fun);
|
Chris@16
|
134 }
|
Chris@16
|
135
|
Chris@16
|
136 // Version which allows explicit specification of the UnaryFunc
|
Chris@16
|
137 // type.
|
Chris@16
|
138 //
|
Chris@16
|
139 // This generator is not provided if UnaryFunc is a function
|
Chris@16
|
140 // pointer type, because it's too dangerous: the default-constructed
|
Chris@16
|
141 // function pointer in the iterator be 0, leading to a runtime
|
Chris@16
|
142 // crash.
|
Chris@16
|
143 template <class UnaryFunc, class Iterator>
|
Chris@101
|
144 inline typename iterators::enable_if<
|
Chris@16
|
145 is_class<UnaryFunc> // We should probably find a cheaper test than is_class<>
|
Chris@16
|
146 , transform_iterator<UnaryFunc, Iterator>
|
Chris@16
|
147 >::type
|
Chris@16
|
148 make_transform_iterator(Iterator it)
|
Chris@16
|
149 {
|
Chris@16
|
150 return transform_iterator<UnaryFunc, Iterator>(it, UnaryFunc());
|
Chris@16
|
151 }
|
Chris@16
|
152
|
Chris@16
|
153 #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION ) && !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
|
Chris@16
|
154 template <class Return, class Argument, class Iterator>
|
Chris@101
|
155 inline transform_iterator< Return (*)(Argument), Iterator, Return>
|
Chris@16
|
156 make_transform_iterator(Iterator it, Return (*fun)(Argument))
|
Chris@16
|
157 {
|
Chris@16
|
158 return transform_iterator<Return (*)(Argument), Iterator, Return>(it, fun);
|
Chris@16
|
159 }
|
Chris@16
|
160 #endif
|
Chris@16
|
161
|
Chris@101
|
162 } // namespace iterators
|
Chris@101
|
163
|
Chris@101
|
164 using iterators::transform_iterator;
|
Chris@101
|
165 using iterators::make_transform_iterator;
|
Chris@101
|
166
|
Chris@16
|
167 } // namespace boost
|
Chris@16
|
168
|
Chris@16
|
169 #include <boost/iterator/detail/config_undef.hpp>
|
Chris@16
|
170
|
Chris@16
|
171 #endif // BOOST_TRANSFORM_ITERATOR_23022003THW_HPP
|