wclog(3C++) - wclog(3C++)
Standard C++ Library Copyright 1998, Rogue Wave Software, Inc.
NAMEwclog
- Controls output to a stream buffer associated with the object stderr
declared in <cstdio>.
SYNOPSIS
#include <iostream>
extern wostream wclog;
wostream wclog;
DESCRIPTION
The object wclog controls output to a stream buffer associated with the
object stderr declared in <cstdio>. The difference between wclog and
wcerr is that wclog is buffered, but wcerr isn't. Therefore, commands
like wclog << L"ERROR !!"; and fprintf(stderr,"ERROR !!"); are not syn‐
chronized. wclog uses the locale codecvt facet to convert the wide
characters it receives to the tiny characters it outputs to stderr.
FORMATTING
The formatting is done through member functions or manipulators. See
cout, wcout or basic_ostream for details.
EXAMPLE
//
// wclog example
//
#include<iostream>
#include<fstream>
void main ( )
{
using namespace std;
// open the file "file_name.txt"
// for reading
wifstream in("file_name.txt");
// output the all file to stdout
if ( in )
wcout << in.rdbuf();
else
// if the wifstream object is in a bad state
// output an error message to stderr
wclog << L"Error while opening the file" << endl;
}
WARNINGSwclog can be used to redirect some of the errors to another recipient.
For example, you might want to redirect them to a file named my_err:
wofstream out("my_err");
if ( out )
wclog.rdbuf(out.rdbuf());
else
cerr << "Error while opening the file" << endl;
Then when you are doing something like wclog << L"error number x"; the error
message is output to the file my_err. You can use the same scheme to redirect
wclog to other devices.
If your compiler does not support namespaces, then you do not need the using
declaration for std.
SEE ALSO
basic_ostream(3C++), basic_iostream(3C++), basic_filebuf(3C++),
cout(3C++), cin(3C++), cerr(3C++), clog(3C++), wcin(3C++), wcout(3C++),
wcerr(3C++), ios_base(3C++), basic_ios(3C++)
Working Paper for Draft Proposed International Standard for Information
Systems--Programming Language C++, Section 27.3.2
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
Rogue Wave Software 02 Apr 1998 wclog(3C++)
