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+/////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2007-2009
+//
+// 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)
+//
+// See http://www.boost.org/libs/intrusive for documentation.
+//
+/////////////////////////////////////////////////////////////////////////////
+
+#ifndef BOOST_INTRUSIVE_DETAIL_TRANSFORM_ITERATOR_HPP
+#define BOOST_INTRUSIVE_DETAIL_TRANSFORM_ITERATOR_HPP
+
+#include <boost/intrusive/detail/config_begin.hpp>
+#include <iterator>
+#include <boost/intrusive/detail/mpl.hpp>
+
+namespace boost {
+namespace intrusive {
+namespace detail {
+
+template <class PseudoReference>
+struct operator_arrow_proxy
+{
+ operator_arrow_proxy(const PseudoReference &px)
+ : m_value(px)
+ {}
+
+ PseudoReference* operator->() const { return &m_value; }
+ // This function is needed for MWCW and BCC, which won't call operator->
+ // again automatically per 13.3.1.2 para 8
+// operator T*() const { return &m_value; }
+ mutable PseudoReference m_value;
+};
+
+template <class T>
+struct operator_arrow_proxy<T&>
+{
+ operator_arrow_proxy(T &px)
+ : m_value(px)
+ {}
+
+ T* operator->() const { return &m_value; }
+ // This function is needed for MWCW and BCC, which won't call operator->
+ // again automatically per 13.3.1.2 para 8
+// operator T*() const { return &m_value; }
+ T &m_value;
+};
+
+template <class Iterator, class UnaryFunction>
+class transform_iterator
+ : public std::iterator
+ < typename Iterator::iterator_category
+ , typename detail::remove_reference<typename UnaryFunction::result_type>::type
+ , typename Iterator::difference_type
+ , operator_arrow_proxy<typename UnaryFunction::result_type>
+ , typename UnaryFunction::result_type>
+{
+ public:
+ explicit transform_iterator(const Iterator &it, const UnaryFunction &f = UnaryFunction())
+ : members_(it, f)
+ {}
+
+ explicit transform_iterator()
+ : members_()
+ {}
+
+ Iterator get_it() const
+ { return members_.m_it; }
+
+ //Constructors
+ transform_iterator& operator++()
+ { increment(); return *this; }
+
+ transform_iterator operator++(int)
+ {
+ transform_iterator result (*this);
+ increment();
+ return result;
+ }
+
+ friend bool operator== (const transform_iterator& i, const transform_iterator& i2)
+ { return i.equal(i2); }
+
+ friend bool operator!= (const transform_iterator& i, const transform_iterator& i2)
+ { return !(i == i2); }
+
+/*
+ friend bool operator> (const transform_iterator& i, const transform_iterator& i2)
+ { return i2 < i; }
+
+ friend bool operator<= (const transform_iterator& i, const transform_iterator& i2)
+ { return !(i > i2); }
+
+ friend bool operator>= (const transform_iterator& i, const transform_iterator& i2)
+ { return !(i < i2); }
+*/
+ friend typename Iterator::difference_type operator- (const transform_iterator& i, const transform_iterator& i2)
+ { return i2.distance_to(i); }
+
+ //Arithmetic
+ transform_iterator& operator+=(typename Iterator::difference_type off)
+ { this->advance(off); return *this; }
+
+ transform_iterator operator+(typename Iterator::difference_type off) const
+ {
+ transform_iterator other(*this);
+ other.advance(off);
+ return other;
+ }
+
+ friend transform_iterator operator+(typename Iterator::difference_type off, const transform_iterator& right)
+ { return right + off; }
+
+ transform_iterator& operator-=(typename Iterator::difference_type off)
+ { this->advance(-off); return *this; }
+
+ transform_iterator operator-(typename Iterator::difference_type off) const
+ { return *this + (-off); }
+
+ typename UnaryFunction::result_type operator*() const
+ { return dereference(); }
+
+ operator_arrow_proxy<typename UnaryFunction::result_type>
+ operator->() const
+ { return operator_arrow_proxy<typename UnaryFunction::result_type>(dereference()); }
+
+ private:
+ struct members
+ : UnaryFunction
+ {
+ members(const Iterator &it, const UnaryFunction &f)
+ : UnaryFunction(f), m_it(it)
+ {}
+
+ members()
+ {}
+
+ Iterator m_it;
+ } members_;
+
+
+ void increment()
+ { ++members_.m_it; }
+
+ void decrement()
+ { --members_.m_it; }
+
+ bool equal(const transform_iterator &other) const
+ { return members_.m_it == other.members_.m_it; }
+
+ bool less(const transform_iterator &other) const
+ { return other.members_.m_it < members_.m_it; }
+
+ typename UnaryFunction::result_type dereference() const
+ { return members_(*members_.m_it); }
+
+ void advance(typename Iterator::difference_type n)
+ { std::advance(members_.m_it, n); }
+
+ typename Iterator::difference_type distance_to(const transform_iterator &other)const
+ { return std::distance(other.members_.m_it, members_.m_it); }
+};
+
+} //namespace detail
+} //namespace intrusive
+} //namespace boost
+
+#include <boost/intrusive/detail/config_end.hpp>
+
+#endif //BOOST_INTRUSIVE_DETAIL_TRANSFORM_ITERATOR_HPP