30 Input/output library [input.output]

30.4 Standard iostream objects [iostream.objects]

30.4.3 Narrow stream objects [narrow.stream.objects]

istream cin;

1
#

The object cin controls input from a stream buffer associated with the object stdin, declared in <cstdio>.

2
#

After the object cin is initialized, cin.tie() returns &cout. Its state is otherwise the same as required for basic_­ios<char>​::​init.

ostream cout;

3
#

The object cout controls output to a stream buffer associated with the object stdout, declared in <cstdio>.

ostream cerr;

4
#

The object cerr controls output to a stream buffer associated with the object stderr, declared in <cstdio>.

5
#

After the object cerr is initialized, cerr.flags() & unitbuf is nonzero and cerr.tie() returns &cout. Its state is otherwise the same as required for basic_­ios<char>​::​init.

ostream clog;

6
#

The object clog controls output to a stream buffer associated with the object stderr, declared in <cstdio>.