text: //////////////////////////////////////////////////////////////////////////////
  //
  // (C) Copyright Ion Gaztanaga 2005-2013.
  // (C) Copyright Gennaro Prota 2003 - 2004.
  //
  // 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/container for documentation.
  //
  //////////////////////////////////////////////////////////////////////////////
  
  #ifndef BOOST_CONTAINER_DETAIL_TRANSFORM_ITERATORS_HPP
  #define BOOST_CONTAINER_DETAIL_TRANSFORM_ITERATORS_HPP
  
  #ifndef BOOST_CONFIG_HPP
  #  include <boost/config.hpp>
  #endif
  
  #if defined(BOOST_HAS_PRAGMA_ONCE)
  #  pragma once
  #endif
  
  #include <boost/container/detail/config_begin.hpp>
  #include <boost/container/detail/workaround.hpp>
  #include <boost/container/detail/type_traits.hpp>
  #include <boost/container/detail/iterator.hpp>
  
  namespace boost {
  namespace container {
  
  template <class PseudoReference>
  struct operator_arrow_proxy
  {
     operator_arrow_proxy(const PseudoReference &px)
        :  m_value(px)
     {}
  
     typedef PseudoReference element_type;
  
     PseudoReference* operator->() const { return &m_value; }
  
     mutable PseudoReference m_value;
  };
  
  template <class T>
  struct operator_arrow_proxy<T&>
  {
     operator_arrow_proxy(T &px)
        :  m_value(px)
     {}
  
     typedef T element_type;
  
     T* operator->() const { return const_cast<T*>(&m_value); }
  
     T &m_value;
  };
  
  template <class Iterator, class UnaryFunction>
  class transform_iterator
     : public UnaryFunction
     , public boost::container::iterator
        < typename Iterator::iterator_category
        , typename container_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())
        :  UnaryFunction(f), m_it(it)
     {}
  
     explicit transform_iterator()
        :  UnaryFunction(), 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());  }
  
     Iterator & base()
     {  return m_it;   }
  
     const Iterator & base() const
     {  return m_it;   }
  
     private:
     Iterator m_it;
  
     void increment()
     { ++m_it; }
  
     void decrement()
     { --m_it; }
  
     bool equal(const transform_iterator &other) const
     {  return m_it == other.m_it;   }
  
     bool less(const transform_iterator &other) const
     {  return other.m_it < m_it;   }
  
     typename UnaryFunction::result_type dereference() const
     { return UnaryFunction::operator()(*m_it); }
  
     void advance(typename Iterator::difference_type n)
     {  boost::container::iterator_advance(m_it, n); }
  
     typename Iterator::difference_type distance_to(const transform_iterator &other)const
     {  return boost::container::iterator_distance(other.m_it, m_it); }
  };
  
  template <class Iterator, class UnaryFunc>
  transform_iterator<Iterator, UnaryFunc>
  make_transform_iterator(Iterator it, UnaryFunc fun)
  {
     return transform_iterator<Iterator, UnaryFunc>(it, fun);
  }
  
  }  //namespace container {
  }  //namespace boost {
  
  #include <boost/container/detail/config_end.hpp>
  
  #endif   //#ifndef BOOST_CONTAINER_DETAIL_TRANSFORM_ITERATORS_HPP
  