wclog (3C++std) - Tru64 UNIX
Standard C++ LibraryCopyright 1996, Rogue Wave Software, Inc.
extern wostream wclog;
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
synchronized. wclog uses the locale codecvt facet to convert the wide
characters it receives to the tiny characters it outputs to stderr.
The formatting is done through member functions or manipulators. See cout,
wcout or basic_ostream for details.
// wclog example
void main ( )
using namespace std;
// open the file "file_name.txt"
// for reading
// output the all file to stdout
if ( in )
wcout << in.rdbuf();
// if the wifstream object is in a bad state
// output an error message to stderr
wclog << L"Error while opening the file" << endl;
wclog 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:
if ( out )
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. Obviously, you can use the
same scheme to redirect wclog to other devices.
basic_ostream(3C++std), iostream(3C++std), basic_filebuf(3C++std),
cout(3C++std), cin(3C++std), cerr(3C++std), clog(3C++std), wcin(3C++std),
wcout(3C++std), wcerr(3C++std), iomanip(3C++std), ios_base(3C++std),
Working Paper for Draft Proposed International Standard for Information
Systems--Programming Language C++, Section 27.3.1
ANSI X3J16/ISO WG21 Joint C++ Committee