1 /////////////////////////////////////////////////////////////////////////////
3 // (C) Copyright Ion Gaztanaga 2007-2009
5 // Distributed under the Boost Software License, Version 1.0.
6 // (See accompanying file LICENSE_1_0.txt or copy at
7 // http://www.boost.org/LICENSE_1_0.txt)
9 // See http://www.boost.org/libs/intrusive for documentation.
11 /////////////////////////////////////////////////////////////////////////////
13 #ifndef BOOST_INTRUSIVE_DETAIL_TRANSFORM_ITERATOR_HPP
14 #define BOOST_INTRUSIVE_DETAIL_TRANSFORM_ITERATOR_HPP
16 #include <boost/intrusive/detail/config_begin.hpp>
18 #include <boost/intrusive/detail/mpl.hpp>
24 template <class PseudoReference>
25 struct operator_arrow_proxy
27 operator_arrow_proxy(const PseudoReference &px)
31 PseudoReference* operator->() const { return &m_value; }
32 // This function is needed for MWCW and BCC, which won't call operator->
33 // again automatically per 13.3.1.2 para 8
34 // operator T*() const { return &m_value; }
35 mutable PseudoReference m_value;
39 struct operator_arrow_proxy<T&>
41 operator_arrow_proxy(T &px)
45 T* operator->() const { return &m_value; }
46 // This function is needed for MWCW and BCC, which won't call operator->
47 // again automatically per 13.3.1.2 para 8
48 // operator T*() const { return &m_value; }
52 template <class Iterator, class UnaryFunction>
53 class transform_iterator
54 : public std::iterator
55 < typename Iterator::iterator_category
56 , typename detail::remove_reference<typename UnaryFunction::result_type>::type
57 , typename Iterator::difference_type
58 , operator_arrow_proxy<typename UnaryFunction::result_type>
59 , typename UnaryFunction::result_type>
62 explicit transform_iterator(const Iterator &it, const UnaryFunction &f = UnaryFunction())
66 explicit transform_iterator()
70 Iterator get_it() const
71 { return members_.m_it; }
74 transform_iterator& operator++()
75 { increment(); return *this; }
77 transform_iterator operator++(int)
79 transform_iterator result (*this);
84 friend bool operator== (const transform_iterator& i, const transform_iterator& i2)
85 { return i.equal(i2); }
87 friend bool operator!= (const transform_iterator& i, const transform_iterator& i2)
88 { return !(i == i2); }
91 friend bool operator> (const transform_iterator& i, const transform_iterator& i2)
94 friend bool operator<= (const transform_iterator& i, const transform_iterator& i2)
97 friend bool operator>= (const transform_iterator& i, const transform_iterator& i2)
100 friend typename Iterator::difference_type operator- (const transform_iterator& i, const transform_iterator& i2)
101 { return i2.distance_to(i); }
104 transform_iterator& operator+=(typename Iterator::difference_type off)
105 { this->advance(off); return *this; }
107 transform_iterator operator+(typename Iterator::difference_type off) const
109 transform_iterator other(*this);
114 friend transform_iterator operator+(typename Iterator::difference_type off, const transform_iterator& right)
115 { return right + off; }
117 transform_iterator& operator-=(typename Iterator::difference_type off)
118 { this->advance(-off); return *this; }
120 transform_iterator operator-(typename Iterator::difference_type off) const
121 { return *this + (-off); }
123 typename UnaryFunction::result_type operator*() const
124 { return dereference(); }
126 operator_arrow_proxy<typename UnaryFunction::result_type>
128 { return operator_arrow_proxy<typename UnaryFunction::result_type>(dereference()); }
134 members(const Iterator &it, const UnaryFunction &f)
135 : UnaryFunction(f), m_it(it)
151 bool equal(const transform_iterator &other) const
152 { return members_.m_it == other.members_.m_it; }
154 bool less(const transform_iterator &other) const
155 { return other.members_.m_it < members_.m_it; }
157 typename UnaryFunction::result_type dereference() const
158 { return members_(*members_.m_it); }
160 void advance(typename Iterator::difference_type n)
161 { std::advance(members_.m_it, n); }
163 typename Iterator::difference_type distance_to(const transform_iterator &other)const
164 { return std::distance(other.members_.m_it, members_.m_it); }
168 } //namespace intrusive
171 #include <boost/intrusive/detail/config_end.hpp>
173 #endif //BOOST_INTRUSIVE_DETAIL_TRANSFORM_ITERATOR_HPP