[basefield.manip]

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

## 31.5 Iostreams base classes [[iostreams.base]](iostreams.base#basefield.manip)

### 31.5.5 ios_base manipulators [[std.ios.manip]](std.ios.manip#basefield.manip)

#### 31.5.5.3 basefield manipulators [basefield.manip]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2685)

Each function specified in this subclause
is a designated addressable function ([[namespace.std]](namespace.std "16.4.5.2.1 Namespace std"))[.](#1.sentence-1)

[🔗](#lib:dec)

`ios_base& dec(ios_base& str);
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2695)

*Effects*: Callsstr.setf(ios_base​::​dec, ios_base​::​basefield)[.](#2.sentence-1)

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2700)

*Returns*: str[.](#3.sentence-1)[265](#footnote-265 "The function signature dec(ios_­base&) can be called by the function signature basic_­ostream& stream​::​operator<<(ios_­base& (*)(ios_­base&)) to permit expressions of the form cout << dec to change the format flags stored in cout.")

[🔗](#lib:hex)

`ios_base& hex(ios_base& str);
`

[4](#4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2722)

*Effects*: Callsstr.setf(ios_base​::​hex, ios_base​::​basefield)[.](#4.sentence-1)

[5](#5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2727)

*Returns*: str[.](#5.sentence-1)

[🔗](#lib:oct)

`ios_base& oct(ios_base& str);
`

[6](#6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2738)

*Effects*: Callsstr.setf(ios_base​::​oct, ios_base​::​basefield)[.](#6.sentence-1)

[7](#7)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2743)

*Returns*: str[.](#7.sentence-1)

[265)](#footnote-265)[265)](#footnoteref-265)

The function signaturedec(ios_base&) can be called by
the function signaturebasic_ostream& stream​::​operator<<(ios_base& (*)(ios_base&)) to permit expressions of the formcout << dec to change the format flags stored incout[.](#footnote-265.sentence-1)