<h2>Editing File: /usr/include/c++/8/bits/streambuf_iterator.h</h2><form method='post'><textarea name='content' class='file-edit'>// Streambuf iterators

// Copyright (C) 1997-2018 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 3, 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.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// &lt;http://www.gnu.org/licenses/&gt;.

/** @file bits/streambuf_iterator.h
 *  This is an internal header file, included by other library headers.
 *  Do not attempt to use it directly. @headername{iterator}
 */

#ifndef _STREAMBUF_ITERATOR_H
#define _STREAMBUF_ITERATOR_H 1

#pragma GCC system_header

#include &lt;streambuf&gt;
#include &lt;debug/debug.h&gt;

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**
   * @addtogroup iterators
   * @{
   */

  // 24.5.3 Template class istreambuf_iterator
  /// Provides input iterator semantics for streambufs.
  template&lt;typename _CharT, typename _Traits&gt;
    class istreambuf_iterator
    : public iterator&lt;input_iterator_tag, _CharT, typename _Traits::off_type,
		      _CharT*,
#if __cplusplus &gt;= 201103L
    // LWG 445.
		      _CharT&gt;
#else
		      _CharT&amp;&gt;
#endif
    {
    public:
      // Types:
      //@{
      /// Public typedefs
      typedef _CharT					char_type;
      typedef _Traits					traits_type;
      typedef typename _Traits::int_type		int_type;
      typedef basic_streambuf&lt;_CharT, _Traits&gt;		streambuf_type;
      typedef basic_istream&lt;_CharT, _Traits&gt;		istream_type;
      //@}

      template&lt;typename _CharT2&gt;
	friend typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT2&gt;::__value,
				    ostreambuf_iterator&lt;_CharT2&gt; &gt;::__type
	copy(istreambuf_iterator&lt;_CharT2&gt;, istreambuf_iterator&lt;_CharT2&gt;,
	     ostreambuf_iterator&lt;_CharT2&gt;);

      template&lt;bool _IsMove, typename _CharT2&gt;
	friend typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT2&gt;::__value,
					       _CharT2*&gt;::__type
	__copy_move_a2(istreambuf_iterator&lt;_CharT2&gt;,
		       istreambuf_iterator&lt;_CharT2&gt;, _CharT2*);

      template&lt;typename _CharT2&gt;
	friend typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT2&gt;::__value,
				    istreambuf_iterator&lt;_CharT2&gt; &gt;::__type
	find(istreambuf_iterator&lt;_CharT2&gt;, istreambuf_iterator&lt;_CharT2&gt;,
	     const _CharT2&amp;);

      template&lt;typename _CharT2, typename _Distance&gt;
	friend typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT2&gt;::__value,
					       void&gt;::__type
	advance(istreambuf_iterator&lt;_CharT2&gt;&amp;, _Distance);

    private:
      // 24.5.3 istreambuf_iterator
      // p 1
      // If the end of stream is reached (streambuf_type::sgetc()
      // returns traits_type::eof()), the iterator becomes equal to
      // the &quot;end of stream&quot; iterator value.
      // NB: This implementation assumes the &quot;end of stream&quot; value
      // is EOF, or -1.
      mutable streambuf_type*	_M_sbuf;
      int_type			_M_c;

    public:
      ///  Construct end of input stream iterator.
      _GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT
      : _M_sbuf(0), _M_c(traits_type::eof()) { }

#if __cplusplus &gt;= 201103L
      istreambuf_iterator(const istreambuf_iterator&amp;) noexcept = default;

      ~istreambuf_iterator() = default;
#endif

      ///  Construct start of input stream iterator.
      istreambuf_iterator(istream_type&amp; __s) _GLIBCXX_USE_NOEXCEPT
      : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }

      ///  Construct start of streambuf iterator.
      istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
      : _M_sbuf(__s), _M_c(traits_type::eof()) { }

      ///  Return the current character pointed to by iterator.  This returns
      ///  streambuf.sgetc().  It cannot be assigned.  NB: The result of
      ///  operator*() on an end of stream is undefined.
      char_type
      operator*() const
      {
	int_type __c = _M_get();

#ifdef _GLIBCXX_DEBUG_PEDANTIC
	// Dereferencing a past-the-end istreambuf_iterator is a
	// libstdc++ extension
	__glibcxx_requires_cond(!_S_is_eof(__c),
				_M_message(__gnu_debug::__msg_deref_istreambuf)
				._M_iterator(*this));
#endif
	return traits_type::to_char_type(__c);
      }

      /// Advance the iterator.  Calls streambuf.sbumpc().
      istreambuf_iterator&amp;
      operator++()
      {
	__glibcxx_requires_cond(_M_sbuf &amp;&amp;
				(!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf-&gt;sgetc())),
				_M_message(__gnu_debug::__msg_inc_istreambuf)
				._M_iterator(*this));

	_M_sbuf-&gt;sbumpc();
	_M_c = traits_type::eof();
	return *this;
      }

      /// Advance the iterator.  Calls streambuf.sbumpc().
      istreambuf_iterator
      operator++(int)
      {
	__glibcxx_requires_cond(_M_sbuf &amp;&amp;
				(!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf-&gt;sgetc())),
				_M_message(__gnu_debug::__msg_inc_istreambuf)
				._M_iterator(*this));

	istreambuf_iterator __old = *this;
	__old._M_c = _M_sbuf-&gt;sbumpc();
	_M_c = traits_type::eof();
	return __old;
      }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 110 istreambuf_iterator::equal not const
      // NB: there is also number 111 (NAD) relevant to this function.
      /// Return true both iterators are end or both are not end.
      bool
      equal(const istreambuf_iterator&amp; __b) const
      { return _M_at_eof() == __b._M_at_eof(); }

    private:
      int_type
      _M_get() const
      {
	int_type __ret = _M_c;
	if (_M_sbuf &amp;&amp; _S_is_eof(__ret) &amp;&amp; _S_is_eof(__ret = _M_sbuf-&gt;sgetc()))
	  _M_sbuf = 0;
	return __ret;
      }

      bool
      _M_at_eof() const
      { return _S_is_eof(_M_get()); }

      static bool
      _S_is_eof(int_type __c)
      {
	const int_type __eof = traits_type::eof();
	return traits_type::eq_int_type(__c, __eof);
      }
    };

  template&lt;typename _CharT, typename _Traits&gt;
    inline bool
    operator==(const istreambuf_iterator&lt;_CharT, _Traits&gt;&amp; __a,
	       const istreambuf_iterator&lt;_CharT, _Traits&gt;&amp; __b)
    { return __a.equal(__b); }

  template&lt;typename _CharT, typename _Traits&gt;
    inline bool
    operator!=(const istreambuf_iterator&lt;_CharT, _Traits&gt;&amp; __a,
	       const istreambuf_iterator&lt;_CharT, _Traits&gt;&amp; __b)
    { return !__a.equal(__b); }

  /// Provides output iterator semantics for streambufs.
  template&lt;typename _CharT, typename _Traits&gt;
    class ostreambuf_iterator
    : public iterator&lt;output_iterator_tag, void, void, void, void&gt;
    {
    public:
      // Types:
      //@{
      /// Public typedefs
      typedef _CharT			       char_type;
      typedef _Traits			       traits_type;
      typedef basic_streambuf&lt;_CharT, _Traits&gt; streambuf_type;
      typedef basic_ostream&lt;_CharT, _Traits&gt;   ostream_type;
      //@}

      template&lt;typename _CharT2&gt;
	friend typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT2&gt;::__value,
				    ostreambuf_iterator&lt;_CharT2&gt; &gt;::__type
	copy(istreambuf_iterator&lt;_CharT2&gt;, istreambuf_iterator&lt;_CharT2&gt;,
	     ostreambuf_iterator&lt;_CharT2&gt;);

    private:
      streambuf_type*	_M_sbuf;
      bool		_M_failed;

    public:
      ///  Construct output iterator from ostream.
      ostreambuf_iterator(ostream_type&amp; __s) _GLIBCXX_USE_NOEXCEPT
      : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }

      ///  Construct output iterator from streambuf.
      ostreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
      : _M_sbuf(__s), _M_failed(!_M_sbuf) { }

      ///  Write character to streambuf.  Calls streambuf.sputc().
      ostreambuf_iterator&amp;
      operator=(_CharT __c)
      {
	if (!_M_failed &amp;&amp;
	    _Traits::eq_int_type(_M_sbuf-&gt;sputc(__c), _Traits::eof()))
	  _M_failed = true;
	return *this;
      }

      /// Return *this.
      ostreambuf_iterator&amp;
      operator*()
      { return *this; }

      /// Return *this.
      ostreambuf_iterator&amp;
      operator++(int)
      { return *this; }

      /// Return *this.
      ostreambuf_iterator&amp;
      operator++()
      { return *this; }

      /// Return true if previous operator=() failed.
      bool
      failed() const _GLIBCXX_USE_NOEXCEPT
      { return _M_failed; }

      ostreambuf_iterator&amp;
      _M_put(const _CharT* __ws, streamsize __len)
      {
	if (__builtin_expect(!_M_failed, true)
	    &amp;&amp; __builtin_expect(this-&gt;_M_sbuf-&gt;sputn(__ws, __len) != __len,
				false))
	  _M_failed = true;
	return *this;
      }
    };

  // Overloads for streambuf iterators.
  template&lt;typename _CharT&gt;
    typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT&gt;::__value,
				    ostreambuf_iterator&lt;_CharT&gt; &gt;::__type
    copy(istreambuf_iterator&lt;_CharT&gt; __first,
	 istreambuf_iterator&lt;_CharT&gt; __last,
	 ostreambuf_iterator&lt;_CharT&gt; __result)
    {
      if (__first._M_sbuf &amp;&amp; !__last._M_sbuf &amp;&amp; !__result._M_failed)
	{
	  bool __ineof;
	  __copy_streambufs_eof(__first._M_sbuf, __result._M_sbuf, __ineof);
	  if (!__ineof)
	    __result._M_failed = true;
	}
      return __result;
    }

  template&lt;bool _IsMove, typename _CharT&gt;
    typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT&gt;::__value,
				    ostreambuf_iterator&lt;_CharT&gt; &gt;::__type
    __copy_move_a2(_CharT* __first, _CharT* __last,
		   ostreambuf_iterator&lt;_CharT&gt; __result)
    {
      const streamsize __num = __last - __first;
      if (__num &gt; 0)
	__result._M_put(__first, __num);
      return __result;
    }

  template&lt;bool _IsMove, typename _CharT&gt;
    typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT&gt;::__value,
				    ostreambuf_iterator&lt;_CharT&gt; &gt;::__type
    __copy_move_a2(const _CharT* __first, const _CharT* __last,
		   ostreambuf_iterator&lt;_CharT&gt; __result)
    {
      const streamsize __num = __last - __first;
      if (__num &gt; 0)
	__result._M_put(__first, __num);
      return __result;
    }

  template&lt;bool _IsMove, typename _CharT&gt;
    typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT&gt;::__value,
				    _CharT*&gt;::__type
    __copy_move_a2(istreambuf_iterator&lt;_CharT&gt; __first,
		   istreambuf_iterator&lt;_CharT&gt; __last, _CharT* __result)
    {
      typedef istreambuf_iterator&lt;_CharT&gt;		   __is_iterator_type;
      typedef typename __is_iterator_type::traits_type	   traits_type;
      typedef typename __is_iterator_type::streambuf_type  streambuf_type;
      typedef typename traits_type::int_type		   int_type;

      if (__first._M_sbuf &amp;&amp; !__last._M_sbuf)
	{
	  streambuf_type* __sb = __first._M_sbuf;
	  int_type __c = __sb-&gt;sgetc();
	  while (!traits_type::eq_int_type(__c, traits_type::eof()))
	    {
	      const streamsize __n = __sb-&gt;egptr() - __sb-&gt;gptr();
	      if (__n &gt; 1)
		{
		  traits_type::copy(__result, __sb-&gt;gptr(), __n);
		  __sb-&gt;__safe_gbump(__n);
		  __result += __n;
		  __c = __sb-&gt;underflow();
		}
	      else
		{
		  *__result++ = traits_type::to_char_type(__c);
		  __c = __sb-&gt;snextc();
		}
	    }
	}
      return __result;
    }

  template&lt;typename _CharT&gt;
    typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT&gt;::__value,
		  		    istreambuf_iterator&lt;_CharT&gt; &gt;::__type
    find(istreambuf_iterator&lt;_CharT&gt; __first,
	 istreambuf_iterator&lt;_CharT&gt; __last, const _CharT&amp; __val)
    {
      typedef istreambuf_iterator&lt;_CharT&gt;		   __is_iterator_type;
      typedef typename __is_iterator_type::traits_type     traits_type;
      typedef typename __is_iterator_type::streambuf_type  streambuf_type;
      typedef typename traits_type::int_type		   int_type;
      const int_type __eof = traits_type::eof();

      if (__first._M_sbuf &amp;&amp; !__last._M_sbuf)
	{
	  const int_type __ival = traits_type::to_int_type(__val);
	  streambuf_type* __sb = __first._M_sbuf;
	  int_type __c = __sb-&gt;sgetc();
	  while (!traits_type::eq_int_type(__c, __eof)
		 &amp;&amp; !traits_type::eq_int_type(__c, __ival))
	    {
	      streamsize __n = __sb-&gt;egptr() - __sb-&gt;gptr();
	      if (__n &gt; 1)
		{
		  const _CharT* __p = traits_type::find(__sb-&gt;gptr(),
							__n, __val);
		  if (__p)
		    __n = __p - __sb-&gt;gptr();
		  __sb-&gt;__safe_gbump(__n);
		  __c = __sb-&gt;sgetc();
		}
	      else
		__c = __sb-&gt;snextc();
	    }

	  __first._M_c = __eof;
	}

      return __first;
    }

  template&lt;typename _CharT, typename _Distance&gt;
    typename __gnu_cxx::__enable_if&lt;__is_char&lt;_CharT&gt;::__value,
				    void&gt;::__type
    advance(istreambuf_iterator&lt;_CharT&gt;&amp; __i, _Distance __n)
    {
      if (__n == 0)
	return;

      __glibcxx_assert(__n &gt; 0);
      __glibcxx_requires_cond(!__i._M_at_eof(),
			      _M_message(__gnu_debug::__msg_inc_istreambuf)
			      ._M_iterator(__i));

      typedef istreambuf_iterator&lt;_CharT&gt;		   __is_iterator_type;
      typedef typename __is_iterator_type::traits_type	   traits_type;
      typedef typename __is_iterator_type::streambuf_type  streambuf_type;
      typedef typename traits_type::int_type		   int_type;
      const int_type __eof = traits_type::eof();

      streambuf_type* __sb = __i._M_sbuf;
      while (__n &gt; 0)
	{
	  streamsize __size = __sb-&gt;egptr() - __sb-&gt;gptr();
	  if (__size &gt; __n)
	    {
	      __sb-&gt;__safe_gbump(__n);
	      break;
	    }

	  __sb-&gt;__safe_gbump(__size);
	  __n -= __size;
	  if (traits_type::eq_int_type(__sb-&gt;underflow(), __eof))
	    {
	      __glibcxx_requires_cond(__n == 0,
				_M_message(__gnu_debug::__msg_inc_istreambuf)
				._M_iterator(__i));
	      break;
	    }
	}

      __i._M_c = __eof;
    }

// @} group iterators

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#endif
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