ostreambuf_iterator

ostreambuf_iteratoroutput_iterator

• Data Type and Member Function Indexes
• Synopsis
• Description
• Interface
• Types
• Constructors
• Member Operators
• Public Member Function
• Examples
• See Also
• Standards Conformance

Data Types
char_type ostream_type streambuf_type traits_type

Member Functions

failed() operator*() operator++() operator=()

#include <streambuf> 
template<class charT, class traits = char_traits<charT> >
class ostreambuf_iterator
: public output_iterator

The template class ostreambuf_iterator writes successive characters onto the stream buffer object from which it was constructed. The operator= is used to write the characters and in case of failure the member function failed() returns true.

template<class charT, class traits = char_traits<charT> >
class ostreambuf_iterator 
: public output_iterator {
 
 public: 

  typedef charT                          char_type;
  typedef traits                         traits_type;
  typedef basic_streambuf<charT, traits> streambuf_type;
  typedef basic_ostream<charT, traits>   ostream_type;

  ostreambuf_iterator(ostream_type& s) throw();

  ostreambuf_iterator(streambuf_type *s) throw();

  ostreambuf_iterator& operator*();
  ostreambuf_iterator& operator++();
  ostreambuf_iterator operator++(int);

  ostreambuf_iterator& operator=(charT c);
       
  bool failed( ) const throw();
    
};

char_type

The type char_type is a synonym for the template parameter charT.

ostream_type

The type ostream_type is an instantiation of class basic_ostream on types charT and traits:

typedef basic_ostream<charT, traits> ostream_type;

streambuf_type

The type streambuf_type is an instantiation of class basic_streambuf on types charT and traits:

typedef basic_streambuf<charT, traits> streambuf_type;

traits_type

The type traits_type is a synonym for the template parameter traits.

ostreambuf_iterator(ostream_type& s) throw();

Constructs an ostreambuf_iterator that uses the basic_streambuf object pointed at by s.rdbuf()to output characters. If s.rdbuf() is a null pointer, calls to the member function failed() return true.

ostreambuf_iterator(streambuf_type *s) throw();

Constructs an ostreambuf_iterator that uses the basic_streambuf object pointed at by s to output characters. If s is a null pointer, calls to the member function failed() return true.

ostreambuf_iterator& 
operator=(charT c);

Inserts the character c into the output sequence of the attached stream buffer. If the operation fails, calls to the member function failed() return true.

ostreambuf_iterator& 
operator++();

Returns *this.

ostreambuf_iterator 
operator++(int);

Returns *this.

ostreambuf_iterator 
operator*();

Returns *this.

bool 
failed() const 
  throw();

Returns true if the iterator failed inserting a characters or false otherwise.

//
// stdlib/examples/manual/ostreambuf_iterator.cpp
//
#include<iostream>
#include<fstream>

void main ( )
{
  using namespace std; 

  // create a filebuf object
  filebuf  buf;

  // open the file iter_out and link it to the filebuf object
  buf.open("iter_out", ios_base::in | ios_base::out );

  // create an ostreambuf_iterator and link it to 
  // the filebuf object
  ostreambuf_iterator<char> out_iter(&buf);

  // output into the file using the ostreambuf_iterator
  for(char i=64; i<128; i++ )
   out_iter = i;

  // seek to the beginning of the file
  buf.pubseekpos(0);
  
  // create an istreambuf_iterator and link it to 
  // the filebuf object
  istreambuf_iterator<char> in_iter(&buf);

  // construct an end of stream iterator
  istreambuf_iterator<char> end_of_stream_iterator;

  cout << endl;

  // output the content of the file
  while( !in_iter.equal(end_of_stream_iterator) )

  // use both operator++ and operator*
  cout << *in_iter++;

  cout << endl;

}

basic_streambuf(3C++), basic_ostream(3C++), istreambuf_iterator(3C++)

Working Paper for Draft Proposed International Standard for Information Systems--Programming Language C++, Section 24.4.4

ANSI X3J16/ISO WG21 Joint C++ Committee

©Copyright 1996, Rogue Wave Software, Inc.