stl_iterator.h

粗糙集应用软件

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Copyright (c) 1996-1998
 * Silicon Graphics Computer Systems, Inc.
 *
 * Copyright (c) 1997
 * Moscow Center for SPARC Technology
 *
 * Copyright (c) 1999 
 * Boris Fomitchev
 *
 * This material is provided "as is", with absolutely no warranty expressed
 * or implied. Any use is at your own risk.
 *
 * Permission to use or copy this software for any purpose is hereby granted 
 * without fee, provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 *
 */

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

#ifndef __SGI_STL_INTERNAL_ITERATOR_H
#define __SGI_STL_INTERNAL_ITERATOR_H

#ifndef __SGI_STL_INTERNAL_ITERATOR_BASE_H
# include <stl_iterator_base.h>
#endif

// streambuf_iterators predeclarations must appear first
#ifndef __STLPORT_IOSFWD
# include <iosfwd>
#endif

__STL_BEGIN_NAMESPACE

template <class _Container>
class back_insert_iterator {
protected:
  _Container* container;
public:
  typedef _Container          container_type;
  typedef output_iterator_tag iterator_category;
#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
  typedef void                value_type;
  typedef void                difference_type;
  typedef void                pointer;
  typedef void                reference;
#endif
  explicit back_insert_iterator(_Container& __x) : container(&__x) {}
  back_insert_iterator<_Container>&
  operator=(const typename _Container::value_type& __value) { 
    container->push_back(__value);
    return *this;
  }
  back_insert_iterator<_Container>& operator*() { return *this; }
  back_insert_iterator<_Container>& operator++() { return *this; }
  back_insert_iterator<_Container>& operator++(int) { return *this; }
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _Container>
inline output_iterator_tag
iterator_category(const back_insert_iterator<_Container>&)
{
  return output_iterator_tag();
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

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

template <class _Container>
class front_insert_iterator {
protected:
  _Container* container;
public:
  typedef _Container          container_type;
  typedef output_iterator_tag iterator_category;
# ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
  typedef void                value_type;
  typedef void                difference_type;
  typedef void                pointer;
  typedef void                reference;
# endif
  explicit front_insert_iterator(_Container& __x) : container(&__x) {}
  front_insert_iterator<_Container>&
  operator=(const typename _Container::value_type& __value) { 
    container->push_front(__value);
    return *this;
  }
  front_insert_iterator<_Container>& operator*() { return *this; }
  front_insert_iterator<_Container>& operator++() { return *this; }
  front_insert_iterator<_Container>& operator++(int) { return *this; }
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _Container>
inline output_iterator_tag
iterator_category(const front_insert_iterator<_Container>&)
{
  return output_iterator_tag();
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

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

template <class _Container>
class insert_iterator {
protected:
  _Container* container;
  typename _Container::iterator iter;
public:
  typedef _Container          container_type;
  typedef output_iterator_tag iterator_category;
# ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
  typedef void                value_type;
  typedef void                difference_type;
  typedef void                pointer;
  typedef void                reference;
# endif
  insert_iterator(_Container& __x, typename _Container::iterator __i) 
    : container(&__x), iter(__i) {}
  insert_iterator<_Container>&
  operator=(const typename _Container::value_type& __value) { 
    iter = container->insert(iter, __value);
    ++iter;
    return *this;
  }
  insert_iterator<_Container>& operator*() { return *this; }
  insert_iterator<_Container>& operator++() { return *this; }
  insert_iterator<_Container>& operator++(int) { return *this; }
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _Container>
inline output_iterator_tag
iterator_category(const insert_iterator<_Container>&)
{
  return output_iterator_tag();
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

template <class _Container, class _Iterator>
inline 
insert_iterator<_Container> inserter(_Container& __x, _Iterator __i)
{
  typedef typename _Container::iterator __iter;
  return insert_iterator<_Container>(__x, __iter(__i));
}


// istream_iterator and ostream_iterator look very different if we're
// using new, templatized iostreams than if we're using the old cfront
// version.

#if defined (__STL_USE_NEW_IOSTREAMS) 

# if  (defined (__STL_USE_OWN_NAMESPACE) || defined (__STLPORT_NEW_IOSTREAMS) || !defined(__STL_USE_NAMESPACES))

#  ifndef __STL_LIMITED_DEFAULT_TEMPLATES
template <class _Tp, 
          class _CharT = __STL_DEFAULTCHAR, class _Traits = char_traits<_CharT>,
          class _Dist = ptrdiff_t> 
#   define __ISI_TMPL_HEADER_ARGUMENTS class _Tp, class _CharT, class _Traits, class _Dist
#   define __ISI_TMPL_ARGUMENTS _Tp, _CharT, _Traits, _Dist
#  else

#   if defined (__STL_MINIMUM_DEFAULT_TEMPLATE_PARAMS) && ! defined (__STL_DEFAULT_TYPE_PARAM)
#    define __ISI_TMPL_HEADER_ARGUMENTS class _Tp
#    define __ISI_TMPL_ARGUMENTS        _Tp
template <class _Tp>
#   else
#    define __ISI_TMPL_HEADER_ARGUMENTS class _Tp, class _Dist
#    define __ISI_TMPL_ARGUMENTS        _Tp, _Dist
template <class _Tp,__DFL_TYPE_PARAM(_Dist, ptrdiff_t)>
#   endif /* __STL_MINIMUM_DEFAULT_TEMPLATE_PARAMS */

#  endif /* __STL_LIMITED_DEFAULT_TEMPLATES */

class istream_iterator {
# ifdef __STL_LIMITED_DEFAULT_TEMPLATES
  typedef char _CharT;
  typedef char_traits<char> _Traits;
#  if defined (__STL_MINIMUM_DEFAULT_TEMPLATE_PARAMS) && ! defined (__STL_DEFAULT_TYPE_PARAM)
  typedef ptrdiff_t _Dist;
#  endif
# endif
  typedef istream_iterator< __ISI_TMPL_ARGUMENTS > _Self;
public:
  typedef _CharT                         char_type;
  typedef _Traits                        traits_type;
  typedef basic_istream<_CharT, _Traits> istream_type;

  typedef input_iterator_tag             iterator_category;
  typedef _Tp                            value_type;
  typedef _Dist                          difference_type;
  typedef const _Tp*                     pointer;
  typedef const _Tp&                     reference;

  istream_iterator() : _M_stream(0), _M_ok(false) {}
  istream_iterator(istream_type& __s) : _M_stream(&__s) { _M_read(); }

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

  _Self& operator++() { 
    _M_read(); 
    return *this;
  }
  _Self operator++(int)  {
    _Self __tmp = *this;
    _M_read();
    return __tmp;
  }

  bool _M_equal(const _Self& __x) const
    { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); }

private:
  istream_type* _M_stream;
  _Tp _M_value;
  bool _M_ok;

  void _M_read() {
    _M_ok = (_M_stream && *_M_stream) ? true : false;
    if (_M_ok) {
      *_M_stream >> _M_value;
      _M_ok = *_M_stream ? true : false;
    }
  }
};

#ifndef __STL_LIMITED_DEFAULT_TEMPLATES
template <class _Tp,
          class _CharT = __STL_DEFAULTCHAR, class _Traits = char_traits<_CharT> >
#else
template <class _Tp>
#endif
class ostream_iterator {
# ifdef __STL_LIMITED_DEFAULT_TEMPLATES
  typedef char _CharT;
  typedef char_traits<char> _Traits;
  typedef ostream_iterator<_Tp> _Self;
# else
  typedef ostream_iterator<_Tp, _CharT, _Traits> _Self;
# endif
public:
  typedef _CharT                         char_type;
  typedef _Traits                        traits_type;
  typedef basic_ostream<_CharT, _Traits> ostream_type;

  typedef output_iterator_tag            iterator_category;
  typedef void                           value_type;
  typedef void                           difference_type;
  typedef void                           pointer;
  typedef void                           reference;

  ostream_iterator(ostream_type& __s) : _M_stream(&__s), _M_string(0) {}
  ostream_iterator(ostream_type& __s, const _CharT* __c) 
    : _M_stream(&__s), _M_string(__c)  {}
  _Self& operator=(const _Tp& __value) { 
    *_M_stream << __value;
    if (_M_string) *_M_stream << _M_string;
    return *this;
  }
  _Self& operator*() { return *this; }
  _Self& operator++() { return *this; } 
  _Self& operator++(int) { return *this; } 
private:
  ostream_type* _M_stream;
  const _CharT* _M_string;
};

// We do not read any characters until operator* is called.  The first
// time operator* is called, it calls getc.  Subsequent calls to getc 
// return a cached character, and calls to operator++ use snextc.  Before
// operator* or operator++ has been called, _M_is_initialized is false.
template<class _CharT, class _Traits>
class istreambuf_iterator
{
public:
  typedef _CharT                           char_type;
  typedef _Traits                          traits_type;
  typedef typename _Traits::int_type       int_type;
  typedef basic_streambuf<_CharT, _Traits> streambuf_type;
  typedef basic_istream<_CharT, _Traits>   istream_type;

  typedef input_iterator_tag               iterator_category;
  typedef _CharT                           value_type;
  typedef typename _Traits::off_type       difference_type;
  typedef const _CharT*                    pointer;
  typedef const _CharT&                    reference;

public:
  istreambuf_iterator(streambuf_type* __p = 0) { this->_M_init(__p); }
  istreambuf_iterator(istream_type& __is) { this->_M_init(__is.rdbuf()); }