[narrow.stream.objects]

# 31 Input/output library [[input.output]](./#input.output)

## 31.4 Standard iostream objects [[iostream.objects]](iostream.objects#narrow.stream.objects)

### 31.4.3 Narrow stream objects [narrow.stream.objects]

[🔗](#lib:cin)

`istream cin;
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L545)

The object cin controls input from a stream buffer associated with the object stdin,
declared in [<cstdio>](cstdio.syn#header:%3ccstdio%3e "31.13.1 Header <cstdio> synopsis [cstdio.syn]")[.](#1.sentence-1)

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L550)

After the objectcin is initialized,cin.tie() returns&cout[.](#2.sentence-1)

Its state is otherwise the same as required for[basic_ios<char>​::​init](istream.cons#lib:basic_ios,init "31.7.5.2.2 Constructors [istream.cons]")[.](#2.sentence-2)

[🔗](#lib:cout)

`ostream cout;
`

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L567)

The object cout controls output to a stream buffer associated with the object stdout,
declared in [<cstdio>](cstdio.syn#header:%3ccstdio%3e "31.13.1 Header <cstdio> synopsis [cstdio.syn]")[.](#3.sentence-1)

[🔗](#lib:cerr)

`ostream cerr;
`

[4](#4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L579)

The object cerr controls output to a stream buffer associated with the object stderr,
declared in [<cstdio>](cstdio.syn#header:%3ccstdio%3e "31.13.1 Header <cstdio> synopsis [cstdio.syn]")[.](#4.sentence-1)

[5](#5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L584)

After the objectcerr is initialized,cerr.flags() & unitbuf is nonzero and cerr.tie() returns &cout[.](#5.sentence-1)

Its state is otherwise the same as required for[basic_ios<char>​::​init](istream.cons#lib:basic_ios,init "31.7.5.2.2 Constructors [istream.cons]")[.](#5.sentence-2)

[🔗](#lib:clog)

`ostream clog;
`

[6](#6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L600)

The object clog controls output to a stream buffer
associated with the object stderr,
declared in [<cstdio>](cstdio.syn#header:%3ccstdio%3e "31.13.1 Header <cstdio> synopsis [cstdio.syn]")[.](#6.sentence-1)