stl_algobase.h

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// Bits and pieces used in algorithms -*- C++ -*-

// Copyright (C) 2001, 2002, 2003, 2004, 2005 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 _ALGOBASE_H
#define _ALGOBASE_H 1

#include <bits/c++config.h>
#include <cstring>
#include <climits>
#include <cstdlib>
#include <cstddef>
#include <new>
#include <iosfwd>
#include <bits/stl_pair.h>
#include <bits/type_traits.h>
#include <bits/stl_iterator_base_types.h>
#include <bits/stl_iterator_base_funcs.h>
#include <bits/stl_iterator.h>
#include <bits/concept_check.h>
#include <debug/debug.h>

namespace std
{
  template<typename _ForwardIterator1, typename _ForwardIterator2>
    inline void
    iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
    {
      typedef typename iterator_traits<_ForwardIterator1>::value_type
    _ValueType1;
      typedef typename iterator_traits<_ForwardIterator2>::value_type
    _ValueType2;

      // concept requirements
      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
                  _ForwardIterator1>)
      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
                  _ForwardIterator2>)
      __glibcxx_function_requires(_ConvertibleConcept<_ValueType1,
                  _ValueType2>)
      __glibcxx_function_requires(_ConvertibleConcept<_ValueType2,
                  _ValueType1>)

      const _ValueType1 __tmp = *__a;
      *__a = *__b;
      *__b = __tmp;
    }

  template<typename _Tp>
    inline void
    swap(_Tp& __a, _Tp& __b)
    {
      // concept requirements
      __glibcxx_function_requires(_SGIAssignableConcept<_Tp>)

      const _Tp __tmp = __a;
      __a = __b;
      __b = __tmp;
    }

  #undef min
  #undef max

  template<typename _Tp>
    inline const _Tp&
    min(const _Tp& __a, const _Tp& __b)
    {
      // concept requirements
      __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
      //return __b < __a ? __b : __a;
      if (__b < __a)
    return __b;
      return __a;
    }

  template<typename _Tp>
    inline const _Tp&
    max(const _Tp& __a, const _Tp& __b)
    {
      // concept requirements
      __glibcxx_function_requires(_LessThanComparableConcept<_Tp>)
      //return  __a < __b ? __b : __a;
      if (__a < __b)
    return __b;
      return __a;
    }

  template<typename _Tp, typename _Compare>
    inline const _Tp&
    min(const _Tp& __a, const _Tp& __b, _Compare __comp)
    {
      //return __comp(__b, __a) ? __b : __a;
      if (__comp(__b, __a))
    return __b;
      return __a;
    }

  template<typename _Tp, typename _Compare>
    inline const _Tp&
    max(const _Tp& __a, const _Tp& __b, _Compare __comp)
    {
      //return __comp(__a, __b) ? __b : __a;
      if (__comp(__a, __b))
    return __b;
      return __a;
    }

  // All of these auxiliary functions serve two purposes.  (1) Replace
  // calls to copy with memmove whenever possible.  (Memmove, not memcpy,
  // because the input and output ranges are permitted to overlap.)
  // (2) If we're using random access iterators, then write the loop as
  // a for loop with an explicit count.

  template<typename _InputIterator, typename _OutputIterator>
    inline _OutputIterator
    __copy(_InputIterator __first, _InputIterator __last,
       _OutputIterator __result, input_iterator_tag)
    {
      for (; __first != __last; ++__result, ++__first)
    *__result = *__first;
      return __result;
    }

  template<typename _RandomAccessIterator, typename _OutputIterator>
    inline _OutputIterator
    __copy(_RandomAccessIterator __first, _RandomAccessIterator __last,
       _OutputIterator __result, random_access_iterator_tag)
    {
      typedef typename iterator_traits<_RandomAccessIterator>::difference_type
          _Distance;
      for (_Distance __n = __last - __first; __n > 0; --__n)
    {
      *__result = *__first;
      ++__first;
      ++__result;
    }
      return __result;
    }

  template<typename _Tp>
    inline _Tp*
    __copy_trivial(const _Tp* __first, const _Tp* __last, _Tp* __result)
    {
      std::memmove(__result, __first, sizeof(_Tp) * (__last - __first));
      return __result + (__last - __first);
    }

  template<typename _InputIterator, typename _OutputIterator>
    inline _OutputIterator
    __copy_aux2(_InputIterator __first, _InputIterator __last,
        _OutputIterator __result, __false_type)
    { return std::__copy(__first, __last, __result,
             std::__iterator_category(__first)); }

  template<typename _InputIterator, typename _OutputIterator>
    inline _OutputIterator
    __copy_aux2(_InputIterator __first, _InputIterator __last,
        _OutputIterator __result, __true_type)
    { return std::__copy(__first, __last, __result,
             std::__iterator_category(__first)); }

  template<typename _Tp>
    inline _Tp*
    __copy_aux2(_Tp* __first, _Tp* __last, _Tp* __result, __true_type)
    { return std::__copy_trivial(__first, __last, __result); }

  template<typename _Tp>
    inline _Tp*
    __copy_aux2(const _Tp* __first, const _Tp* __last, _Tp* __result,
        __true_type)
    { return std::__copy_trivial(__first, __last, __result); }

  template<typename _InputIterator, typename _OutputIterator>
    inline _OutputIterator
    __copy_ni2(_InputIterator __first, _InputIterator __last,
           _OutputIterator __result, __true_type)
    {
      typedef typename iterator_traits<_InputIterator>::value_type
    _ValueType;
      typedef typename __type_traits<
    _ValueType>::has_trivial_assignment_operator _Trivial;
      return _OutputIterator(std::__copy_aux2(__first, __last, __result.base(),
                          _Trivial()));
    }

  template<typename _InputIterator, typename _OutputIterator>
    inline _OutputIterator
    __copy_ni2(_InputIterator __first, _InputIterator __last,
           _OutputIterator __result, __false_type)
    {
      typedef typename iterator_traits<_InputIterator>::value_type _ValueType;
      typedef typename __type_traits<
    _ValueType>::has_trivial_assignment_operator _Trivial;
      return std::__copy_aux2(__first, __last, __result, _Trivial());
    }

  template<typename _InputIterator, typename _OutputIterator>
    inline _OutputIterator
    __copy_ni1(_InputIterator __first, _InputIterator __last,
           _OutputIterator __result, __true_type)
    {
      typedef typename _Is_normal_iterator<_OutputIterator>::_Normal __Normal;
      return std::__copy_ni2(__first.base(), __last.base(),
                 __result, __Normal());
    }

  template<typename _InputIterator, typename _OutputIterator>
    inline _OutputIterator
    __copy_ni1(_InputIterator __first, _InputIterator __last,
           _OutputIterator __result, __false_type)
    {
      typedef typename _Is_normal_iterator<_OutputIterator>::_Normal __Normal;
      return std::__copy_ni2(__first, __last, __result, __Normal());
    }

  template<typename _InputIterator, typename _OutputIterator>
    inline _OutputIterator
    copy(_InputIterator __first, _InputIterator __last,
     _OutputIterator __result)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
      __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
        typename iterator_traits<_InputIterator>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

       typedef typename _Is_normal_iterator<_InputIterator>::_Normal __Normal;
       return std::__copy_ni1(__first, __last, __result, __Normal());
    }

  template<typename _BidirectionalIterator1, typename _BidirectionalIterator2>
    inline _BidirectionalIterator2
    __copy_backward(_BidirectionalIterator1 __first,
            _BidirectionalIterator1 __last,
            _BidirectionalIterator2 __result,
            bidirectional_iterator_tag)
    {
      while (__first != __last)
        *--__result = *--__last;
      return __result;
    }

  template<typename _RandomAccessIterator, typename _BidirectionalIterator>
    inline _BidirectionalIterator
    __copy_backward(_RandomAccessIterator __first, _RandomAccessIterator __last,
            _BidirectionalIterator __result, random_access_iterator_tag)
    {
      typename iterator_traits<_RandomAccessIterator>::difference_type __n;
      for (__n = __last - __first; __n > 0; --__n)
        *--__result = *--__last;
      return __result;
    }


  // This dispatch class is a workaround for compilers that do not
  // have partial ordering of function templates.  All we're doing is
  // creating a specialization so that we can turn a call to copy_backward
  // into a memmove whenever possible.
  template<typename _BidirectionalIterator1, typename _BidirectionalIterator2,
           typename _BoolType>
    struct __copy_backward_dispatch
    {
      static _BidirectionalIterator2
      copy(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
       _BidirectionalIterator2 __result)
      { return std::__copy_backward(__first, __last, __result,
                    std::__iterator_category(__first)); }
    };

  template<typename _Tp>
    struct __copy_backward_dispatch<_Tp*, _Tp*, __true_type>
    {
      static _Tp*
      copy(const _Tp* __first, const _Tp* __last, _Tp* __result)
      {
    const ptrdiff_t _Num = __last - __first;
    std::memmove(__result - _Num, __first, sizeof(_Tp) * _Num);
    return __result - _Num;
      }
    };

  template<typename _Tp>
    struct __copy_backward_dispatch<const _Tp*, _Tp*, __true_type>
    {
      static _Tp*
      copy(const _Tp* __first, const _Tp* __last, _Tp* __result)
      {
    return  std::__copy_backward_dispatch<_Tp*, _Tp*, __true_type>
	  ::copy(__first, __last, __result);
      }
    };

  template<typename _BI1, typename _BI2>
    inline _BI2
    __copy_backward_aux(_BI1 __first, _BI1 __last, _BI2 __result)
    {
      typedef typename __type_traits<typename iterator_traits<_BI2>::value_type>
                ::has_trivial_assignment_operator _Trivial;
      return
    std::__copy_backward_dispatch<_BI1, _BI2, _Trivial>::copy(__first,
                                  __last,
                                  __result);
    }

  template <typename _BI1, typename _BI2>
    inline _BI2
    __copy_backward_output_normal_iterator(_BI1 __first, _BI1 __last,
                       _BI2 __result, __true_type)
    { return _BI2(std::__copy_backward_aux(__first, __last, __result.base())); }

  template <typename _BI1, typename _BI2>
    inline _BI2
    __copy_backward_output_normal_iterator(_BI1 __first, _BI1 __last,
                       _BI2 __result, __false_type)
    { return std::__copy_backward_aux(__first, __last, __result); }

  template <typename _BI1, typename _BI2>
    inline _BI2
    __copy_backward_input_normal_iterator(_BI1 __first, _BI1 __last,
                      _BI2 __result, __true_type)
    {
      typedef typename _Is_normal_iterator<_BI2>::_Normal __Normal;
      return std::__copy_backward_output_normal_iterator(__first.base(),
                             __last.base(),
                             __result, __Normal());
    }

  template <typename _BI1, typename _BI2>
    inline _BI2
    __copy_backward_input_normal_iterator(_BI1 __first, _BI1 __last,
                      _BI2 __result, __false_type)
    {
      typedef typename _Is_normal_iterator<_BI2>::_Normal __Normal;
      return std::__copy_backward_output_normal_iterator(__first, __last,
                             __result, __Normal());
    }

  template <typename _BI1, typename _BI2>
    inline _BI2
    copy_backward(_BI1 __first, _BI1 __last, _BI2 __result)
    {
      // concept requirements
      __glibcxx_function_requires(_BidirectionalIteratorConcept<_BI1>)
      __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<_BI2>)
      __glibcxx_function_requires(_ConvertibleConcept<
        typename iterator_traits<_BI1>::value_type,
        typename iterator_traits<_BI2>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);

      typedef typename _Is_normal_iterator<_BI1>::_Normal __Normal;
      return std::__copy_backward_input_normal_iterator(__first, __last,
                            __result, __Normal());
    }


  template<typename _ForwardIterator, typename _Tp>
    void
    fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
    {
      // concept requirements
      __glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
                  _ForwardIterator>)
      __glibcxx_requires_valid_range(__first, __last);

      for ( ; __first != __last; ++__first)
    *__first = __value;
    }

  template<typename _OutputIterator, typename _Size, typename _Tp>
    _OutputIterator
    fill_n(_OutputIterator __first, _Size __n, const _Tp& __value)
    {
      // concept requirements
      __glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,_Tp>)

      for ( ; __n > 0; --__n, ++__first)
    *__first = __value;
      return __first;
    }

  // Specialization: for one-byte types we can use memset.
  inline void
  fill(unsigned char* __first, unsigned char* __last, const unsigned char& __c)
  {
    __glibcxx_requires_valid_range(__first, __last);
    const unsigned char __tmp = __c;
    std::memset(__first, __tmp, __last - __first);
  }

  inline void
  fill(signed char* __first, signed char* __last, const signed char& __c)
  {
    __glibcxx_requires_valid_range(__first, __last);
    const signed char __tmp = __c;
    std::memset(__first, static_cast<unsigned char>(__tmp), __last - __first);
  }

  inline void
  fill(char* __first, char* __last, const char& __c)
  {
    __glibcxx_requires_valid_range(__first, __last);
    const char __tmp = __c;
    std::memset(__first, static_cast<unsigned char>(__tmp), __last - __first);
  }

  template<typename _Size>
    inline unsigned char*
    fill_n(unsigned char* __first, _Size __n, const unsigned char& __c)
    {
      std::fill(__first, __first + __n, __c);
      return __first + __n;
    }

  template<typename _Size>
    inline signed char*
    fill_n(char* __first, _Size __n, const signed char& __c)
    {
      std::fill(__first, __first + __n, __c);
      return __first + __n;
    }

  template<typename _Size>
    inline char*
    fill_n(char* __first, _Size __n, const char& __c)
    {
      std::fill(__first, __first + __n, __c);
      return __first + __n;
    }


  template<typename _InputIterator1, typename _InputIterator2>
    pair<_InputIterator1, _InputIterator2>
    mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
         _InputIterator2 __first2)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_function_requires(_EqualOpConcept<
        typename iterator_traits<_InputIterator1>::value_type,
        typename iterator_traits<_InputIterator2>::value_type>)
      __glibcxx_requires_valid_range(__first1, __last1);

      while (__first1 != __last1 && *__first1 == *__first2)
        {
      ++__first1;
      ++__first2;
        }
      return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
    }

  template<typename _InputIterator1, typename _InputIterator2,
       typename _BinaryPredicate>
    pair<_InputIterator1, _InputIterator2>
    mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
         _InputIterator2 __first2, _BinaryPredicate __binary_pred)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_requires_valid_range(__first1, __last1);

      while (__first1 != __last1 && __binary_pred(*__first1, *__first2))
        {
      ++__first1;
      ++__first2;
        }
      return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
    }

  template<typename _InputIterator1, typename _InputIterator2>
    inline bool
    equal(_InputIterator1 __first1, _InputIterator1 __last1,
      _InputIterator2 __first2)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_function_requires(_EqualOpConcept<
        typename iterator_traits<_InputIterator1>::value_type,
        typename iterator_traits<_InputIterator2>::value_type>)
      __glibcxx_requires_valid_range(__first1, __last1);

      for ( ; __first1 != __last1; ++__first1, ++__first2)
    if (!(*__first1 == *__first2))
      return false;
      return true;
    }

  template<typename _InputIterator1, typename _InputIterator2,
       typename _BinaryPredicate>
    inline bool
    equal(_InputIterator1 __first1, _InputIterator1 __last1,
      _InputIterator2 __first2,
      _BinaryPredicate __binary_pred)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_requires_valid_range(__first1, __last1);

      for ( ; __first1 != __last1; ++__first1, ++__first2)
    if (!__binary_pred(*__first1, *__first2))
      return false;
      return true;
    }

  template<typename _InputIterator1, typename _InputIterator2>
    bool
    lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
                _InputIterator2 __first2, _InputIterator2 __last2)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_function_requires(_LessThanOpConcept<
        typename iterator_traits<_InputIterator1>::value_type,
        typename iterator_traits<_InputIterator2>::value_type>)
      __glibcxx_function_requires(_LessThanOpConcept<
        typename iterator_traits<_InputIterator2>::value_type,
        typename iterator_traits<_InputIterator1>::value_type>)
      __glibcxx_requires_valid_range(__first1, __last1);
      __glibcxx_requires_valid_range(__first2, __last2);

      for (;__first1 != __last1 && __first2 != __last2; ++__first1, ++__first2)
    {
      if (*__first1 < *__first2)
        return true;
      if (*__first2 < *__first1)
        return false;
    }
      return __first1 == __last1 && __first2 != __last2;
    }

  template<typename _InputIterator1, typename _InputIterator2,
       typename _Compare>
    bool
    lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
                _InputIterator2 __first2, _InputIterator2 __last2,
                _Compare __comp)
    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
      __glibcxx_requires_valid_range(__first1, __last1);
      __glibcxx_requires_valid_range(__first2, __last2);

      for ( ; __first1 != __last1 && __first2 != __last2
        ; ++__first1, ++__first2)
    {
      if (__comp(*__first1, *__first2))
        return true;
      if (__comp(*__first2, *__first1))
        return false;
    }
      return __first1 == __last1 && __first2 != __last2;
    }

  inline bool
  lexicographical_compare(const unsigned char* __first1,
              const unsigned char* __last1,
              const unsigned char* __first2,
              const unsigned char* __last2)
  {
    __glibcxx_requires_valid_range(__first1, __last1);
    __glibcxx_requires_valid_range(__first2, __last2);

    const size_t __len1 = __last1 - __first1;
    const size_t __len2 = __last2 - __first2;
    const int __result = std::memcmp(__first1, __first2,
                     std::min(__len1, __len2));
    return __result != 0 ? __result < 0 : __len1 < __len2;
  }

  inline bool
  lexicographical_compare(const char* __first1, const char* __last1,
              const char* __first2, const char* __last2)
  {
    __glibcxx_requires_valid_range(__first1, __last1);
    __glibcxx_requires_valid_range(__first2, __last2);

#if CHAR_MAX == SCHAR_MAX
    return std::lexicographical_compare((const signed char*) __first1,
                    (const signed char*) __last1,
                    (const signed char*) __first2,
                    (const signed char*) __last2);
#else /* CHAR_MAX == SCHAR_MAX */
    return std::lexicographical_compare((const unsigned char*) __first1,
                    (const unsigned char*) __last1,
                    (const unsigned char*) __first2,
                    (const unsigned char*) __last2);
#endif /* CHAR_MAX == SCHAR_MAX */
  }

} // namespace std

#endif

---