ceph/src/boost/libs/intrusive/include/boost/intrusive/detail/transform_iterator.hpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2007-2013
   4 //
   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)
   8 //
   9 // See http://www.boost.org/libs/intrusive for documentation.
  10 //
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #ifndef BOOST_INTRUSIVE_DETAIL_TRANSFORM_ITERATOR_HPP
  14 #define BOOST_INTRUSIVE_DETAIL_TRANSFORM_ITERATOR_HPP
  15
  16 #ifndef BOOST_CONFIG_HPP
  17 #  include <boost/config.hpp>
  18 #endif
  19
  20 #if defined(BOOST_HAS_PRAGMA_ONCE)
  21 #  pragma once
  22 #endif
  23
  24 #include <boost/intrusive/detail/config_begin.hpp>
  25 #include <boost/intrusive/detail/workaround.hpp>
  26 #include <boost/intrusive/detail/mpl.hpp>
  27 #include <boost/intrusive/detail/iterator.hpp>
  28
  29 namespace boost {
  30 namespace intrusive {
  31 namespace detail {
  32
  33 template <class PseudoReference>
  34 struct operator_arrow_proxy
  35 {
  36    BOOST_INTRUSIVE_FORCEINLINE operator_arrow_proxy(const PseudoReference &px)
  37       :  m_value(px)
  38    {}
  39
  40    BOOST_INTRUSIVE_FORCEINLINE PseudoReference* operator->() const { return &m_value; }
  41    // This function is needed for MWCW and BCC, which won't call operator->
  42    // again automatically per 13.3.1.2 para 8
  43 //   operator T*() const { return &m_value; }
  44    mutable PseudoReference m_value;
  45 };
  46
  47 template <class T>
  48 struct operator_arrow_proxy<T&>
  49 {
  50    BOOST_INTRUSIVE_FORCEINLINE operator_arrow_proxy(T &px)
  51       :  m_value(px)
  52    {}
  53
  54    BOOST_INTRUSIVE_FORCEINLINE T* operator->() const { return &m_value; }
  55    // This function is needed for MWCW and BCC, which won't call operator->
  56    // again automatically per 13.3.1.2 para 8
  57 //   operator T*() const { return &m_value; }
  58    T &m_value;
  59 };
  60
  61 template <class Iterator, class UnaryFunction>
  62 class transform_iterator
  63 {
  64    public:
  65    typedef typename Iterator::iterator_category                                           iterator_category;
  66    typedef typename detail::remove_reference<typename UnaryFunction::result_type>::type   value_type;
  67    typedef typename Iterator::difference_type                                             difference_type;
  68    typedef operator_arrow_proxy<typename UnaryFunction::result_type>                      pointer;
  69    typedef typename UnaryFunction::result_type                                            reference;
  70
  71    explicit transform_iterator(const Iterator &it, const UnaryFunction &f = UnaryFunction())
  72       :  members_(it, f)
  73    {}
  74
  75    explicit transform_iterator()
  76       :  members_()
  77    {}
  78
  79    BOOST_INTRUSIVE_FORCEINLINE Iterator get_it() const
  80    {  return members_.m_it;   }
  81
  82    //Constructors
  83    BOOST_INTRUSIVE_FORCEINLINE transform_iterator& operator++()
  84    { increment();   return *this;   }
  85
  86    BOOST_INTRUSIVE_FORCEINLINE transform_iterator operator++(int)
  87    {
  88       transform_iterator result (*this);
  89       increment();
  90       return result;
  91    }
  92
  93    BOOST_INTRUSIVE_FORCEINLINE friend bool operator== (const transform_iterator& i, const transform_iterator& i2)
  94    { return i.equal(i2); }
  95
  96    BOOST_INTRUSIVE_FORCEINLINE friend bool operator!= (const transform_iterator& i, const transform_iterator& i2)
  97    { return !(i == i2); }
  98
  99    BOOST_INTRUSIVE_FORCEINLINE friend typename Iterator::difference_type operator- (const transform_iterator& i, const transform_iterator& i2)
 100    { return i2.distance_to(i); }
 101
 102    //Arithmetic
 103    transform_iterator& operator+=(typename Iterator::difference_type off)
 104    {  this->advance(off); return *this;   }
 105
 106    BOOST_INTRUSIVE_FORCEINLINE transform_iterator operator+(typename Iterator::difference_type off) const
 107    {
 108       transform_iterator other(*this);
 109       other.advance(off);
 110       return other;
 111    }
 112
 113    BOOST_INTRUSIVE_FORCEINLINE friend transform_iterator operator+(typename Iterator::difference_type off, const transform_iterator& right)
 114    {  return right + off; }
 115
 116    BOOST_INTRUSIVE_FORCEINLINE transform_iterator& operator-=(typename Iterator::difference_type off)
 117    {  this->advance(-off); return *this;   }
 118
 119    BOOST_INTRUSIVE_FORCEINLINE transform_iterator operator-(typename Iterator::difference_type off) const
 120    {  return *this + (-off);  }
 121
 122    BOOST_INTRUSIVE_FORCEINLINE typename UnaryFunction::result_type operator*() const
 123    { return dereference(); }
 124
 125    BOOST_INTRUSIVE_FORCEINLINE operator_arrow_proxy<typename UnaryFunction::result_type>
 126       operator->() const
 127    { return operator_arrow_proxy<typename UnaryFunction::result_type>(dereference());  }
 128
 129    private:
 130    struct members
 131       :  UnaryFunction
 132    {
 133       BOOST_INTRUSIVE_FORCEINLINE members(const Iterator &it, const UnaryFunction &f)
 134          :  UnaryFunction(f), m_it(it)
 135       {}
 136
 137       BOOST_INTRUSIVE_FORCEINLINE members()
 138       {}
 139
 140       Iterator m_it;
 141    } members_;
 142
 143
 144    BOOST_INTRUSIVE_FORCEINLINE void increment()
 145    { ++members_.m_it; }
 146
 147    BOOST_INTRUSIVE_FORCEINLINE void decrement()
 148    { --members_.m_it; }
 149
 150    BOOST_INTRUSIVE_FORCEINLINE bool equal(const transform_iterator &other) const
 151    {  return members_.m_it == other.members_.m_it;   }
 152
 153    BOOST_INTRUSIVE_FORCEINLINE bool less(const transform_iterator &other) const
 154    {  return other.members_.m_it < members_.m_it;   }
 155
 156    typename UnaryFunction::result_type dereference() const
 157    { return members_(*members_.m_it); }
 158
 159    void advance(typename Iterator::difference_type n)
 160    {  boost::intrusive::iterator_advance(members_.m_it, n); }
 161
 162    typename Iterator::difference_type distance_to(const transform_iterator &other)const
 163    {  return boost::intrusive::iterator_distance(other.members_.m_it, members_.m_it); }
 164 };
 165
 166 } //namespace detail
 167 } //namespace intrusive
 168 } //namespace boost
 169
 170 #include <boost/intrusive/detail/config_end.hpp>
 171
 172 #endif //BOOST_INTRUSIVE_DETAIL_TRANSFORM_ITERATOR_HPP