27 Input/output library [input.output]

27.4 Standard iostream objects [iostream.objects]

27.4.2 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 ([basic.ios.cons]).

ostream cout;

3

The object cout controls output to a stream buffer associated with the object stdout, declared in <cstdio> ([c.files]).

ostream cerr;

4

The object cerr controls output to a stream buffer associated with the object stderr, declared in <cstdio> ([c.files]).

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 ([basic.ios.cons]).

ostream clog;

6

The object clog controls output to a stream buffer associated with the object stderr, declared in <cstdio> ([c.files]).