stl_iterator.h

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// Iterators -*- C++ -*-

// Copyright (C) 2001, 2002, 2004 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996-1998
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */

#ifndef _ITERATOR_H
#define _ITERATOR_H 1

namespace std
{
  // 24.4.1 Reverse iterators
  template<typename _Iterator>
    class reverse_iterator
    : public iterator<typename iterator_traits<_Iterator>::iterator_category,
              typename iterator_traits<_Iterator>::value_type,
              typename iterator_traits<_Iterator>::difference_type,
              typename iterator_traits<_Iterator>::pointer,
                      typename iterator_traits<_Iterator>::reference>
    {
    protected:
      _Iterator current;

    public:
      typedef _Iterator                        iterator_type;
      typedef typename iterator_traits<_Iterator>::difference_type
                                   difference_type;
      typedef typename iterator_traits<_Iterator>::reference   reference;
      typedef typename iterator_traits<_Iterator>::pointer     pointer;

    public:
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 235 No specification of default ctor for reverse_iterator
      reverse_iterator() : current() { }

      explicit
      reverse_iterator(iterator_type __x) : current(__x) { }

      reverse_iterator(const reverse_iterator& __x)
      : current(__x.current) { }

      template<typename _Iter>
        reverse_iterator(const reverse_iterator<_Iter>& __x)
    : current(__x.base()) { }

      iterator_type
      base() const
      { return current; }

      reference
      operator*() const
      {
    _Iterator __tmp = current;
    return *--__tmp;
      }

      pointer
      operator->() const
      { return &(operator*()); }

      reverse_iterator&
      operator++()
      {
    --current;
    return *this;
      }

      reverse_iterator
      operator++(int)
      {
    reverse_iterator __tmp = *this;
    --current;
    return __tmp;
      }

      reverse_iterator&
      operator--()
      {
    ++current;
    return *this;
      }

      reverse_iterator operator--(int)
      {
    reverse_iterator __tmp = *this;
    ++current;
    return __tmp;
      }

      reverse_iterator
      operator+(difference_type __n) const
      { return reverse_iterator(current - __n); }

      reverse_iterator&
      operator+=(difference_type __n)
      {
    current -= __n;
    return *this;
      }

      reverse_iterator
      operator-(difference_type __n) const
      { return reverse_iterator(current + __n); }

      reverse_iterator&
      operator-=(difference_type __n)
      {
    current += __n;
    return *this;
      }

      reference
      operator[](difference_type __n) const
      { return *(*this + __n); }
    };


  template<typename _Iterator>
    inline bool
    operator==(const reverse_iterator<_Iterator>& __x,
           const reverse_iterator<_Iterator>& __y)
    { return __x.base() == __y.base(); }

  template<typename _Iterator>
    inline bool
    operator<(const reverse_iterator<_Iterator>& __x,
          const reverse_iterator<_Iterator>& __y)
    { return __y.base() < __x.base(); }

  template<typename _Iterator>
    inline bool
    operator!=(const reverse_iterator<_Iterator>& __x,
           const reverse_iterator<_Iterator>& __y)
    { return !(__x == __y); }

  template<typename _Iterator>
    inline bool
    operator>(const reverse_iterator<_Iterator>& __x,
          const reverse_iterator<_Iterator>& __y)
    { return __y < __x; }

  template<typename _Iterator>
    inline bool
    operator<=(const reverse_iterator<_Iterator>& __x,
        const reverse_iterator<_Iterator>& __y)
    { return !(__y < __x); }

  template<typename _Iterator>
    inline bool
    operator>=(const reverse_iterator<_Iterator>& __x,
           const reverse_iterator<_Iterator>& __y)
    { return !(__x < __y); }

  template<typename _Iterator>
    inline typename reverse_iterator<_Iterator>::difference_type
    operator-(const reverse_iterator<_Iterator>& __x,
          const reverse_iterator<_Iterator>& __y)
    { return __y.base() - __x.base(); }

  template<typename _Iterator>
    inline reverse_iterator<_Iterator>
    operator+(typename reverse_iterator<_Iterator>::difference_type __n,
          const reverse_iterator<_Iterator>& __x)
    { return reverse_iterator<_Iterator>(__x.base() - __n); }

  // 24.4.2.2.1 back_insert_iterator
  template<typename _Container>
    class back_insert_iterator
    : public iterator<output_iterator_tag, void, void, void, void>
    {
    protected:
      _Container* container;

    public:
      typedef _Container          container_type;

      explicit
      back_insert_iterator(_Container& __x) : container(&__x) { }

      back_insert_iterator&
      operator=(typename _Container::const_reference __value)
      {
    container->push_back(__value);
    return *this;
      }

      back_insert_iterator&
      operator*()
      { return *this; }

      back_insert_iterator&
      operator++()
      { return *this; }

      back_insert_iterator
      operator++(int)
      { return *this; }
    };

  template<typename _Container>
    inline back_insert_iterator<_Container>
    back_inserter(_Container& __x)
    { return back_insert_iterator<_Container>(__x); }

  template<typename _Container>
    class front_insert_iterator
    : public iterator<output_iterator_tag, void, void, void, void>
    {
    protected:
      _Container* container;

    public:
      typedef _Container          container_type;

      explicit front_insert_iterator(_Container& __x) : container(&__x) { }

      front_insert_iterator&
      operator=(typename _Container::const_reference __value)
      {
    container->push_front(__value);
    return *this;
      }

      front_insert_iterator&
      operator*()
      { return *this; }

      front_insert_iterator&
      operator++()
      { return *this; }

      front_insert_iterator
      operator++(int)
      { return *this; }
    };

  template<typename _Container>
    inline front_insert_iterator<_Container>
    front_inserter(_Container& __x)
    { return front_insert_iterator<_Container>(__x); }

  template<typename _Container>
    class insert_iterator
    : public iterator<output_iterator_tag, void, void, void, void>
    {
    protected:
      _Container* container;
      typename _Container::iterator iter;

    public:
      typedef _Container          container_type;

      insert_iterator(_Container& __x, typename _Container::iterator __i)
      : container(&__x), iter(__i) {}

      insert_iterator&
      operator=(const typename _Container::const_reference __value)
      {
    iter = container->insert(iter, __value);
    ++iter;
    return *this;
      }

      insert_iterator&
      operator*()
      { return *this; }

      insert_iterator&
      operator++()
      { return *this; }

      insert_iterator&
      operator++(int)
      { return *this; }
    };

  template<typename _Container, typename _Iterator>
    inline insert_iterator<_Container>
    inserter(_Container& __x, _Iterator __i)
    {
      return insert_iterator<_Container>(__x,
                     typename _Container::iterator(__i));
    }
} // namespace std

namespace __gnu_cxx
{
  // This iterator adapter is 'normal' in the sense that it does not
  // change the semantics of any of the operators of its iterator
  // parameter.  Its primary purpose is to convert an iterator that is
  // not a class, e.g. a pointer, into an iterator that is a class.
  // The _Container parameter exists solely so that different containers
  // using this template can instantiate different types, even if the
  // _Iterator parameter is the same.
  using std::iterator_traits;
  using std::iterator;
  template<typename _Iterator, typename _Container>
    class __normal_iterator
    {
    protected:
      _Iterator _M_current;

    public:
      typedef typename iterator_traits<_Iterator>::iterator_category
                                                             iterator_category;
      typedef typename iterator_traits<_Iterator>::value_type  value_type;
      typedef typename iterator_traits<_Iterator>::difference_type
                                                             difference_type;
      typedef typename iterator_traits<_Iterator>::reference reference;
      typedef typename iterator_traits<_Iterator>::pointer   pointer;

      __normal_iterator() : _M_current(_Iterator()) { }

      explicit
      __normal_iterator(const _Iterator& __i) : _M_current(__i) { }

      // Allow iterator to const_iterator conversion
      template<typename _Iter>
        inline __normal_iterator(const __normal_iterator<_Iter,
                 _Container>& __i)
    : _M_current(__i.base()) { }

      // Forward iterator requirements
      reference
      operator*() const
      { return *_M_current; }

      pointer
      operator->() const
      { return _M_current; }

      __normal_iterator&
      operator++()
      {
    ++_M_current;
    return *this;
      }

      __normal_iterator
      operator++(int)
      { return __normal_iterator(_M_current++); }

      // Bidirectional iterator requirements
      __normal_iterator&
      operator--()
      {
    --_M_current;
    return *this;
      }

      __normal_iterator
      operator--(int)
      { return __normal_iterator(_M_current--); }

      // Random access iterator requirements
      reference
      operator[](const difference_type& __n) const
      { return _M_current[__n]; }

      __normal_iterator&
      operator+=(const difference_type& __n)
      { _M_current += __n; return *this; }

      __normal_iterator
      operator+(const difference_type& __n) const
      { return __normal_iterator(_M_current + __n); }

      __normal_iterator&
      operator-=(const difference_type& __n)
      { _M_current -= __n; return *this; }

      __normal_iterator
      operator-(const difference_type& __n) const
      { return __normal_iterator(_M_current - __n); }

      const _Iterator&
      base() const
      { return _M_current; }
    };

  // Note: In what follows, the left- and right-hand-side iterators are
  // allowed to vary in types (conceptually in cv-qualification) so that
  // comparaison between cv-qualified and non-cv-qualified iterators be
  // valid.  However, the greedy and unfriendly operators in std::rel_ops
  // will make overload resolution ambiguous (when in scope) if we don't
  // provide overloads whose operands are of the same type.  Can someone
  // remind me what generic programming is about? -- Gaby

  // Forward iterator requirements
  template<typename _IteratorL, typename _IteratorR, typename _Container>
    inline bool
    operator==(const __normal_iterator<_IteratorL, _Container>& __lhs,
           const __normal_iterator<_IteratorR, _Container>& __rhs)
    { return __lhs.base() == __rhs.base(); }

  template<typename _Iterator, typename _Container>
    inline bool
    operator==(const __normal_iterator<_Iterator, _Container>& __lhs,
           const __normal_iterator<_Iterator, _Container>& __rhs)
    { return __lhs.base() == __rhs.base(); }

  template<typename _IteratorL, typename _IteratorR, typename _Container>
    inline bool
    operator!=(const __normal_iterator<_IteratorL, _Container>& __lhs,
           const __normal_iterator<_IteratorR, _Container>& __rhs)
    { return __lhs.base() != __rhs.base(); }

  template<typename _Iterator, typename _Container>
    inline bool
    operator!=(const __normal_iterator<_Iterator, _Container>& __lhs,
           const __normal_iterator<_Iterator, _Container>& __rhs)
    { return __lhs.base() != __rhs.base(); }

  // Random access iterator requirements
  template<typename _IteratorL, typename _IteratorR, typename _Container>
    inline bool
    operator<(const __normal_iterator<_IteratorL, _Container>& __lhs,
          const __normal_iterator<_IteratorR, _Container>& __rhs)
    { return __lhs.base() < __rhs.base(); }

  template<typename _Iterator, typename _Container>
    inline bool
    operator<(const __normal_iterator<_Iterator, _Container>& __lhs,
          const __normal_iterator<_Iterator, _Container>& __rhs)
    { return __lhs.base() < __rhs.base(); }

  template<typename _IteratorL, typename _IteratorR, typename _Container>
    inline bool
    operator>(const __normal_iterator<_IteratorL, _Container>& __lhs,
          const __normal_iterator<_IteratorR, _Container>& __rhs)
    { return __lhs.base() > __rhs.base(); }

  template<typename _Iterator, typename _Container>
    inline bool
    operator>(const __normal_iterator<_Iterator, _Container>& __lhs,
          const __normal_iterator<_Iterator, _Container>& __rhs)
    { return __lhs.base() > __rhs.base(); }

  template<typename _IteratorL, typename _IteratorR, typename _Container>
    inline bool
    operator<=(const __normal_iterator<_IteratorL, _Container>& __lhs,
           const __normal_iterator<_IteratorR, _Container>& __rhs)
    { return __lhs.base() <= __rhs.base(); }

  template<typename _Iterator, typename _Container>
    inline bool
    operator<=(const __normal_iterator<_Iterator, _Container>& __lhs,
           const __normal_iterator<_Iterator, _Container>& __rhs)
    { return __lhs.base() <= __rhs.base(); }

  template<typename _IteratorL, typename _IteratorR, typename _Container>
    inline bool
    operator>=(const __normal_iterator<_IteratorL, _Container>& __lhs,
           const __normal_iterator<_IteratorR, _Container>& __rhs)
    { return __lhs.base() >= __rhs.base(); }

  template<typename _Iterator, typename _Container>
    inline bool
    operator>=(const __normal_iterator<_Iterator, _Container>& __lhs,
           const __normal_iterator<_Iterator, _Container>& __rhs)
    { return __lhs.base() >= __rhs.base(); }

  // _GLIBCXX_RESOLVE_LIB_DEFECTS
  // According to the resolution of DR179 not only the various comparison
  // operators but also operator- must accept mixed iterator/const_iterator
  // parameters.
  template<typename _IteratorL, typename _IteratorR, typename _Container>
    inline typename __normal_iterator<_IteratorL, _Container>::difference_type
    operator-(const __normal_iterator<_IteratorL, _Container>& __lhs,
          const __normal_iterator<_IteratorR, _Container>& __rhs)
    { return __lhs.base() - __rhs.base(); }

  template<typename _Iterator, typename _Container>
    inline __normal_iterator<_Iterator, _Container>
    operator+(typename __normal_iterator<_Iterator, _Container>::difference_type
          __n, const __normal_iterator<_Iterator, _Container>& __i)
    { return __normal_iterator<_Iterator, _Container>(__i.base() + __n); }
} // namespace __gnu_cxx

#endif

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// mode:C++
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