stl_algobase.h

c++ STL source code, hash and vector etc

/*
 *
 * 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.
 */

/* NOTE: This is an internal header file, included by other STL headers.
 *   You should not attempt to use it directly.
 */


#ifndef __SGI_STL_INTERNAL_ALGOBASE_H
#define __SGI_STL_INTERNAL_ALGOBASE_H

#ifndef __STL_CONFIG_H
#include <stl_config.h>
#endif
#ifndef __SGI_STL_INTERNAL_RELOPS
#include <stl_relops.h>
#endif
#ifndef __SGI_STL_INTERNAL_PAIR_H
#include <stl_pair.h>
#endif
#ifndef __TYPE_TRAITS_H
#include <type_traits.h>
#endif

#include <string.h>
#include <limits.h>
#include <stdlib.h>
#include <stddef.h>
#include <new.h>

#ifdef __STL_USE_NEW_IOSTREAMS 
#include <iosfwd>
#else /* __STL_USE_NEW_IOSTREAMS */
#include <iostream.h>
#endif /* __STL_USE_NEW_IOSTREAMS */

#ifndef __SGI_STL_INTERNAL_ITERATOR_H
#include <stl_iterator_base.h>
#include <stl_iterator.h>
#endif

// We pick up concept_checks.h from stl_iterator_base.h.

__STL_BEGIN_NAMESPACE

// swap and iter_swap

template <class _ForwardIter1, class _ForwardIter2, class _Tp>
inline void __iter_swap(_ForwardIter1 __a, _ForwardIter2 __b, _Tp*) {
  _Tp __tmp = *__a;
  *__a = *__b;
  *__b = __tmp;
}

template <class _ForwardIter1, class _ForwardIter2>
inline void iter_swap(_ForwardIter1 __a, _ForwardIter2 __b) {
  __STL_REQUIRES(_ForwardIter1, _Mutable_ForwardIterator);
  __STL_REQUIRES(_ForwardIter2, _Mutable_ForwardIterator);
  __STL_CONVERTIBLE(typename iterator_traits<_ForwardIter1>::value_type,
                    typename iterator_traits<_ForwardIter2>::value_type);
  __STL_CONVERTIBLE(typename iterator_traits<_ForwardIter2>::value_type,
                    typename iterator_traits<_ForwardIter1>::value_type);
  __iter_swap(__a, __b, __VALUE_TYPE(__a));
}

template <class _Tp>
inline void swap(_Tp& __a, _Tp& __b) {
  __STL_REQUIRES(_Tp, _Assignable);
  _Tp __tmp = __a;
  __a = __b;
  __b = __tmp;
}

//--------------------------------------------------
// min and max

#if !defined(__BORLANDC__) || __BORLANDC__ >= 0x540 /* C++ Builder 4.0 */

#undef min
#undef max

template <class _Tp>
inline const _Tp& min(const _Tp& __a, const _Tp& __b) {
  __STL_REQUIRES(_Tp, _LessThanComparable);
  return __b < __a ? __b : __a;
}

template <class _Tp>
inline const _Tp& max(const _Tp& __a, const _Tp& __b) {
  __STL_REQUIRES(_Tp, _LessThanComparable);
  return  __a < __b ? __b : __a;
}

#endif /* __BORLANDC__ */

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

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

//--------------------------------------------------
// copy

// 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 <class _InputIter, class _OutputIter, class _Distance>
inline _OutputIter __copy(_InputIter __first, _InputIter __last,
                          _OutputIter __result,
                          input_iterator_tag, _Distance*)
{
  for ( ; __first != __last; ++__result, ++__first)
    *__result = *__first;
  return __result;
}

template <class _RandomAccessIter, class _OutputIter, class _Distance>
inline _OutputIter
__copy(_RandomAccessIter __first, _RandomAccessIter __last,
       _OutputIter __result, random_access_iterator_tag, _Distance*)
{
  for (_Distance __n = __last - __first; __n > 0; --__n) {
    *__result = *__first;
    ++__first;
    ++__result;
  }
  return __result;
}

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

#if defined(__STL_FUNCTION_TMPL_PARTIAL_ORDER)

template <class _InputIter, class _OutputIter>
inline _OutputIter __copy_aux2(_InputIter __first, _InputIter __last,
                               _OutputIter __result, __false_type) {
  return __copy(__first, __last, __result,
                __ITERATOR_CATEGORY(__first),
                __DISTANCE_TYPE(__first));
}

template <class _InputIter, class _OutputIter>
inline _OutputIter __copy_aux2(_InputIter __first, _InputIter __last,
                               _OutputIter __result, __true_type) {
  return __copy(__first, __last, __result,
                __ITERATOR_CATEGORY(__first),
                __DISTANCE_TYPE(__first));
}

#ifndef __USLC__

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

#endif /* __USLC__ */

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


template <class _InputIter, class _OutputIter, class _Tp>
inline _OutputIter __copy_aux(_InputIter __first, _InputIter __last,
                              _OutputIter __result, _Tp*) {
  typedef typename __type_traits<_Tp>::has_trivial_assignment_operator
          _Trivial;
  return __copy_aux2(__first, __last, __result, _Trivial());
}

template <class _InputIter, class _OutputIter>
inline _OutputIter copy(_InputIter __first, _InputIter __last,
                        _OutputIter __result) {
  __STL_REQUIRES(_InputIter, _InputIterator);
  __STL_REQUIRES(_OutputIter, _OutputIterator);
  return __copy_aux(__first, __last, __result, __VALUE_TYPE(__first));
}

// Hack for compilers that don't have partial ordering of function templates
// but do have partial specialization of class templates.
#elif defined(__STL_CLASS_PARTIAL_SPECIALIZATION)

template <class _InputIter, class _OutputIter, class _BoolType>
struct __copy_dispatch {
  static _OutputIter copy(_InputIter __first, _InputIter __last,
                          _OutputIter __result) {
    typedef typename iterator_traits<_InputIter>::iterator_category _Category;
    typedef typename iterator_traits<_InputIter>::difference_type _Distance;
    return __copy(__first, __last, __result, _Category(), (_Distance*) 0);
  }
};

template <class _Tp>
struct __copy_dispatch<_Tp*, _Tp*, __true_type>
{
  static _Tp* copy(const _Tp* __first, const _Tp* __last, _Tp* __result) {
    return __copy_trivial(__first, __last, __result);
  }
};

template <class _Tp>
struct __copy_dispatch<const _Tp*, _Tp*, __true_type>
{
  static _Tp* copy(const _Tp* __first, const _Tp* __last, _Tp* __result) {
    return __copy_trivial(__first, __last, __result);
  }
};

template <class _InputIter, class _OutputIter>
inline _OutputIter copy(_InputIter __first, _InputIter __last,
                        _OutputIter __result) {
  __STL_REQUIRES(_InputIter, _InputIterator);
  __STL_REQUIRES(_OutputIter, _OutputIterator);
  typedef typename iterator_traits<_InputIter>::value_type _Tp;
  typedef typename __type_traits<_Tp>::has_trivial_assignment_operator
          _Trivial;
  return __copy_dispatch<_InputIter, _OutputIter, _Trivial>
    ::copy(__first, __last, __result);
}

// Fallback for compilers with neither partial ordering nor partial
// specialization.  Define the faster version for the basic builtin
// types.
#else /* __STL_CLASS_PARTIAL_SPECIALIZATION */

template <class _InputIter, class _OutputIter>
inline _OutputIter copy(_InputIter __first, _InputIter __last,
                        _OutputIter __result)
{
  return __copy(__first, __last, __result,
                __ITERATOR_CATEGORY(__first),
                __DISTANCE_TYPE(__first));
}

#define __SGI_STL_DECLARE_COPY_TRIVIAL(_Tp)                                \
  inline _Tp* copy(const _Tp* __first, const _Tp* __last, _Tp* __result) { \
    memmove(__result, __first, sizeof(_Tp) * (__last - __first));          \
    return __result + (__last - __first);                                  \
  }

__SGI_STL_DECLARE_COPY_TRIVIAL(char)
__SGI_STL_DECLARE_COPY_TRIVIAL(signed char)
__SGI_STL_DECLARE_COPY_TRIVIAL(unsigned char)
__SGI_STL_DECLARE_COPY_TRIVIAL(short)
__SGI_STL_DECLARE_COPY_TRIVIAL(unsigned short)
__SGI_STL_DECLARE_COPY_TRIVIAL(int)
__SGI_STL_DECLARE_COPY_TRIVIAL(unsigned int)
__SGI_STL_DECLARE_COPY_TRIVIAL(long)
__SGI_STL_DECLARE_COPY_TRIVIAL(unsigned long)
#ifdef __STL_HAS_WCHAR_T
__SGI_STL_DECLARE_COPY_TRIVIAL(wchar_t)
#endif
#ifdef _STL_LONG_LONG
__SGI_STL_DECLARE_COPY_TRIVIAL(long long)
__SGI_STL_DECLARE_COPY_TRIVIAL(unsigned long long)
#endif 
__SGI_STL_DECLARE_COPY_TRIVIAL(float)
__SGI_STL_DECLARE_COPY_TRIVIAL(double)
__SGI_STL_DECLARE_COPY_TRIVIAL(long double)

#undef __SGI_STL_DECLARE_COPY_TRIVIAL
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

//--------------------------------------------------
// copy_backward

template <class _BidirectionalIter1, class _BidirectionalIter2, 
          class _Distance>
inline _BidirectionalIter2 __copy_backward(_BidirectionalIter1 __first, 
                                           _BidirectionalIter1 __last, 
                                           _BidirectionalIter2 __result,
                                           bidirectional_iterator_tag,
                                           _Distance*)
{
  while (__first != __last)
    *--__result = *--__last;
  return __result;
}

template <class _RandomAccessIter, class _BidirectionalIter, class _Distance>
inline _BidirectionalIter __copy_backward(_RandomAccessIter __first, 
                                          _RandomAccessIter __last, 
                                          _BidirectionalIter __result,
                                          random_access_iterator_tag,
                                          _Distance*)
{
  for (_Distance __n = __last - __first; __n > 0; --__n)
    *--__result = *--__last;
  return __result;
}

#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION 

// 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 <class _BidirectionalIter1, class _BidirectionalIter2,
          class _BoolType>
struct __copy_backward_dispatch
{
  typedef typename iterator_traits<_BidirectionalIter1>::iterator_category 
          _Cat;
  typedef typename iterator_traits<_BidirectionalIter1>::difference_type
          _Distance;

  static _BidirectionalIter2 copy(_BidirectionalIter1 __first, 
                                  _BidirectionalIter1 __last,