stl_queue.h

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// Queue implementation -*- C++ -*-

// Copyright (C) 2001, 2002, 2003, 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// 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) 1996,1997
 * 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 _QUEUE_H
#define _QUEUE_H 1

#include <bits/concept_check.h>
#include <debug/debug.h>

namespace std
{
  // Forward declarations of operators < and ==, needed for friend declaration.
  template<typename _Tp, typename _Sequence = deque<_Tp> >
    class queue;

  template<typename _Tp, typename _Seq>
    inline bool
    operator==(const queue<_Tp,_Seq>&, const queue<_Tp,_Seq>&);

  template<typename _Tp, typename _Seq>
    inline bool
    operator<(const queue<_Tp,_Seq>&, const queue<_Tp,_Seq>&);

  template<typename _Tp, typename _Sequence>
    class queue
    {
      // concept requirements
      typedef typename _Sequence::value_type _Sequence_value_type;
      __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
      __glibcxx_class_requires(_Sequence, _FrontInsertionSequenceConcept)
      __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
      __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)

      template<typename _Tp1, typename _Seq1>
        friend bool
        operator==(const queue<_Tp1, _Seq1>&, const queue<_Tp1, _Seq1>&);

      template<typename _Tp1, typename _Seq1>
        friend bool
        operator<(const queue<_Tp1, _Seq1>&, const queue<_Tp1, _Seq1>&);

    public:
      typedef typename _Sequence::value_type                value_type;
      typedef typename _Sequence::reference                 reference;
      typedef typename _Sequence::const_reference           const_reference;
      typedef typename _Sequence::size_type                 size_type;
      typedef          _Sequence                            container_type;

    protected:
      _Sequence c;

    public:
      explicit
      queue(const _Sequence& __c = _Sequence()) : c(__c) {}

      bool
      empty() const
      { return c.empty(); }

      size_type
      size() const
      { return c.size(); }

      reference
      front()
      {
    __glibcxx_requires_nonempty();
    return c.front();
      }

      const_reference
      front() const
      {
    __glibcxx_requires_nonempty();
    return c.front();
      }

      reference
      back()
      {
    __glibcxx_requires_nonempty();
    return c.back();
      }

      const_reference
      back() const
      {
    __glibcxx_requires_nonempty();
    return c.back();
      }

      void
      push(const value_type& __x)
      { c.push_back(__x); }

      void
      pop()
      {
    __glibcxx_requires_nonempty();
    c.pop_front();
      }
    };


  template<typename _Tp, typename _Sequence>
    inline bool
    operator==(const queue<_Tp,_Sequence>& __x,
           const queue<_Tp,_Sequence>& __y)
    { return __x.c == __y.c; }

  template<typename _Tp, typename _Sequence>
    inline bool
    operator<(const queue<_Tp,_Sequence>& __x, const queue<_Tp,_Sequence>& __y)
    { return __x.c < __y.c; }

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

  template<typename _Tp, typename _Sequence>
    inline bool
    operator>(const queue<_Tp,_Sequence>& __x, const queue<_Tp,_Sequence>& __y)
    { return __y < __x; }

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

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

  template<typename _Tp, typename _Sequence = vector<_Tp>,
       typename _Compare  = less<typename _Sequence::value_type> >
    class priority_queue
    {
      // concept requirements
      typedef typename _Sequence::value_type _Sequence_value_type;
      __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
      __glibcxx_class_requires(_Sequence, _SequenceConcept)
      __glibcxx_class_requires(_Sequence, _RandomAccessContainerConcept)
      __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
      __glibcxx_class_requires4(_Compare, bool, _Tp,_Tp,_BinaryFunctionConcept)

    public:
      typedef typename _Sequence::value_type                value_type;
      typedef typename _Sequence::reference                 reference;
      typedef typename _Sequence::const_reference           const_reference;
      typedef typename _Sequence::size_type                 size_type;
      typedef          _Sequence                            container_type;

    protected:
      //  See queue::c for notes on these names.
      _Sequence  c;
      _Compare   comp;

    public:
      explicit
      priority_queue(const _Compare& __x = _Compare(),
             const _Sequence& __s = _Sequence())
      : c(__s), comp(__x)
      { std::make_heap(c.begin(), c.end(), comp); }

      template<typename _InputIterator>
        priority_queue(_InputIterator __first, _InputIterator __last,
               const _Compare& __x = _Compare(),
               const _Sequence& __s = _Sequence())
    : c(__s), comp(__x)
        {
      __glibcxx_requires_valid_range(__first, __last);
      c.insert(c.end(), __first, __last);
      std::make_heap(c.begin(), c.end(), comp);
    }

      bool
      empty() const { return c.empty(); }

      size_type
      size() const { return c.size(); }

      const_reference
      top() const
      {
    __glibcxx_requires_nonempty();
    return c.front();
      }

      void
      push(const value_type& __x)
      {
    try
        {
          c.push_back(__x);
          std::push_heap(c.begin(), c.end(), comp);
        }
    catch(...)
        {
          c.clear();
          __throw_exception_again;
        }
      }

      void
      pop()
      {
    __glibcxx_requires_nonempty();
    try
        {
          std::pop_heap(c.begin(), c.end(), comp);
          c.pop_back();
        }
    catch(...)
        {
          c.clear();
          __throw_exception_again;
        }
      }
    };

  // No equality/comparison operators are provided for priority_queue.
} // namespace std

#endif /* _QUEUE_H */

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