src/Util/CastIterator.hpp

   1 /*
   2  * Copyright (C) 2010-2011 Max Kellermann <max@duempel.org>
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * - Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * - Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the
  14  * distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  19  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  20  * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  27  * OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #ifndef XCSOAR_CAST_ITERATOR_HPP
  31 #define XCSOAR_CAST_ITERATOR_HPP
  32
  33 #include <iterator>
  34
  35 template<typename VT, typename IT>
  36 class CastIterator {
  37   IT iterator;
  38
  39 public:
  40   typedef typename IT::iterator_category iterator_category;
  41   typedef typename IT::difference_type difference_type;
  42   typedef VT value_type;
  43   typedef VT *pointer;
  44   typedef VT &reference;
  45
  46   CastIterator() = default;
  47
  48   constexpr
  49   CastIterator(const IT _iterator):iterator(_iterator) {}
  50
  51   reference operator*() const {
  52     return static_cast<reference>(*iterator);
  53   }
  54
  55   pointer operator->() const {
  56     return static_cast<pointer>(iterator.IT::operator->());
  57   }
  58
  59   CastIterator<VT,IT> &operator++() {
  60     iterator = ++iterator;
  61     return *this;
  62   }
  63
  64   CastIterator<VT,IT> operator++(int) {
  65     CastIterator<VT,IT> old = *this;
  66     iterator++;
  67     return old;
  68   }
  69
  70   CastIterator<VT,IT> &operator--() {
  71     iterator = --iterator;
  72     return *this;
  73   }
  74
  75   CastIterator<VT,IT> operator--(int) {
  76     CastIterator<VT,IT> old = *this;
  77     iterator--;
  78     return old;
  79   }
  80
  81   bool operator==(const CastIterator<VT,IT> &other) const {
  82     return iterator == other.iterator;
  83   }
  84
  85   bool operator!=(const CastIterator<VT,IT> &other) const {
  86     return iterator != other.iterator;
  87   }
  88 };
  89
  90 #endif