Standard C++ Library Reference ISO/IEC (VERSION3)

extern wistream wcin;
extern wostream wcout;
extern wostream wcerr;
extern wostream wclog;
};
cerr
extern ostream cerr;
The object controls unbuffered insertions to the standard error output as a byte stream. Once the
object is constructed, the expression cerr.flags() & unitbuf is nonzero.
cin
extern istream cin;
The object controls extractions from the standard input as a byte stream. Once the object is
constructed, the call cin.tie() returns &cout.
clog
extern ostream clog;
The object controls buffered insertions to the standard error output as a byte stream.
cout
extern ostream cout;
The object controls insertions to the standard output as a byte stream.
wcerr
extern wostream wcerr;
The object controls unbuffered insertions to the standard error output as a wide stream. Once
the object is constructed, the expression wcerr.flags() & unitbuf is nonzero.