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// Streambuf iterators

// Copyright (C) 1997, 1998, 1999, 2000, 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.

/** @file streambuf_iterator.h

 *  This is an internal header file, included by other library headers.

 *  You should not attempt to use it directly.

 */

#ifndef _STREAMBUF_ITERATOR_H

#define _STREAMBUF_ITERATOR_H 1

#pragma GCC system_header

#include <streambuf>

#include <debug/debug.h>

// NB: Should specialize copy, find algorithms for streambuf iterators.

namespace std

{

  // 24.5.3 Template class istreambuf_iterator

  /// Provides input iterator semantics for streambufs.

  template<typename _CharT, typename _Traits>

    class istreambuf_iterator

    : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type,

                      _CharT*, _CharT&>

    {

    public:

      // Types:

      //@{

      /// Public typedefs

      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;

      //@}

    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 "end of stream" iterator value.

      // NB: This implementation assumes the "end of stream" value

      // is EOF, or -1.

      mutable streambuf_type*   _M_sbuf;

      mutable int_type          _M_c;

    public:

      ///  Construct end of input stream iterator.

      istreambuf_iterator() throw()

      : _M_sbuf(0), _M_c(traits_type::eof()) { }

      ///  Construct start of input stream iterator.

      istreambuf_iterator(istream_type& __s) throw()

      : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }

      ///  Construct start of streambuf iterator.

      istreambuf_iterator(streambuf_type* __s) throw()

      : _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

      {

#ifdef _GLIBCXX_DEBUG_PEDANTIC

        // Dereferencing a past-the-end istreambuf_iterator is a

        // libstdc++ extension

        __glibcxx_requires_cond(!_M_at_eof(),

                                _M_message(__gnu_debug::__msg_deref_istreambuf)

                                ._M_iterator(*this));

#endif

        return traits_type::to_char_type(_M_get());

      }

      /// Advance the iterator.  Calls streambuf.sbumpc().

      istreambuf_iterator&

      operator++()

      {

        __glibcxx_requires_cond(!_M_at_eof(),

                                _M_message(__gnu_debug::__msg_inc_istreambuf)

                                ._M_iterator(*this));

        if (_M_sbuf)

          {

            _M_sbuf->sbumpc();

            _M_c = traits_type::eof();

          }

        return *this;

      }

      /// Advance the iterator.  Calls streambuf.sbumpc().

      istreambuf_iterator

      operator++(int)

      {

        __glibcxx_requires_cond(!_M_at_eof(),

                                _M_message(__gnu_debug::__msg_inc_istreambuf)

                                ._M_iterator(*this));

        istreambuf_iterator __old = *this;

        if (_M_sbuf)

          {

            __old._M_c = _M_sbuf->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, Future) pending on this function.

      /// Return true both iterators are end or both are not end.

      bool

      equal(const istreambuf_iterator& __b) const

      {

        const bool __thiseof = _M_at_eof();

        const bool __beof = __b._M_at_eof();

        return (__thiseof && __beof || (!__thiseof && !__beof));

      }

    private:

      int_type

      _M_get() const

      {

        const int_type __eof = traits_type::eof();

        int_type __ret = __eof;

        if (_M_sbuf)

          {

            if (!traits_type::eq_int_type(_M_c, __eof))

              __ret = _M_c;

            else if (!traits_type::eq_int_type((__ret = _M_sbuf->sgetc()),

                                               __eof))

              _M_c = __ret;

            else

              _M_sbuf = 0;

          }

        return __ret;

      }

      bool

      _M_at_eof() const

      {

        const int_type __eof = traits_type::eof();

        return traits_type::eq_int_type(_M_get(), __eof);

      }

    };

  template<typename _CharT, typename _Traits>

    inline bool

    operator==(const istreambuf_iterator<_CharT, _Traits>& __a,

               const istreambuf_iterator<_CharT, _Traits>& __b)

    { return __a.equal(__b); }

  template<typename _CharT, typename _Traits>

    inline bool

    operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,

               const istreambuf_iterator<_CharT, _Traits>& __b)

    { return !__a.equal(__b); }

  /// Provides output iterator semantics for streambufs.

  template<typename _CharT, typename _Traits>

    class ostreambuf_iterator

    : public iterator<output_iterator_tag, void, void, void, void>

    {

    public:

      // Types:

      //@{

      /// Public typedefs

      typedef _CharT                           char_type;

      typedef _Traits                          traits_type;

      typedef basic_streambuf<_CharT, _Traits> streambuf_type;

      typedef basic_ostream<_CharT, _Traits>   ostream_type;

      //@}

    private:

      streambuf_type*   _M_sbuf;

      bool              _M_failed;

    public:

      ///  Construct output iterator from ostream.

      ostreambuf_iterator(ostream_type& __s) throw ()

      : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }

      ///  Construct output iterator from streambuf.

      ostreambuf_iterator(streambuf_type* __s) throw ()

      : _M_sbuf(__s), _M_failed(!_M_sbuf) { }

      ///  Write character to streambuf.  Calls streambuf.sputc().

      ostreambuf_iterator&

      operator=(_CharT __c)

      {

        if (!_M_failed &&

            _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))

          _M_failed = true;

        return *this;

      }

      /// Return *this.

      ostreambuf_iterator&

      operator*()

      { return *this; }

      /// Return *this.

      ostreambuf_iterator&

      operator++(int)

      { return *this; }

      /// Return *this.

      ostreambuf_iterator&

      operator++()

      { return *this; }

      /// Return true if previous operator=() failed.

      bool

      failed() const throw()

      { return _M_failed; }

      ostreambuf_iterator&

      _M_put(const _CharT* __ws, streamsize __len)

      {

        if (__builtin_expect(!_M_failed, true)

            && __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len,

                                false))

          _M_failed = true;

        return *this;

      }

    };

} // namespace std

#endif