[std.ios.manip]

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

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

### 31.5.5 ios_base manipulators [std.ios.manip]

#### [31.5.5.1](#fmtflags.manip) fmtflags manipulators [[fmtflags.manip]](fmtflags.manip)

[1](#fmtflags.manip-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2401)

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

[🔗](#lib:boolalpha)

`ios_base& boolalpha(ios_base& str);
`

[2](#fmtflags.manip-2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2411)

*Effects*: Callsstr.setf(ios_base​::​boolalpha)[.](#fmtflags.manip-2.sentence-1)

[3](#fmtflags.manip-3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2416)

*Returns*: str[.](#fmtflags.manip-3.sentence-1)

[🔗](#lib:noboolalpha)

`ios_base& noboolalpha(ios_base& str);
`

[4](#fmtflags.manip-4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2427)

*Effects*: Callsstr.unsetf(ios_base​::​boolalpha)[.](#fmtflags.manip-4.sentence-1)

[5](#fmtflags.manip-5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2432)

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

[🔗](#lib:showbase)

`ios_base& showbase(ios_base& str);
`

[6](#fmtflags.manip-6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2443)

*Effects*: Callsstr.setf(ios_base​::​showbase)[.](#fmtflags.manip-6.sentence-1)

[7](#fmtflags.manip-7)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2448)

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

[🔗](#lib:noshowbase)

`ios_base& noshowbase(ios_base& str);
`

[8](#fmtflags.manip-8)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2459)

*Effects*: Callsstr.unsetf(ios_base​::​showbase)[.](#fmtflags.manip-8.sentence-1)

[9](#fmtflags.manip-9)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2464)

*Returns*: str[.](#fmtflags.manip-9.sentence-1)

[🔗](#lib:showpoint)

`ios_base& showpoint(ios_base& str);
`

[10](#fmtflags.manip-10)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2475)

*Effects*: Callsstr.setf(ios_base​::​showpoint)[.](#fmtflags.manip-10.sentence-1)

[11](#fmtflags.manip-11)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2480)

*Returns*: str[.](#fmtflags.manip-11.sentence-1)

[🔗](#lib:noshowpoint)

`ios_base& noshowpoint(ios_base& str);
`

[12](#fmtflags.manip-12)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2491)

*Effects*: Callsstr.unsetf(ios_base​::​showpoint)[.](#fmtflags.manip-12.sentence-1)

[13](#fmtflags.manip-13)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2496)

*Returns*: str[.](#fmtflags.manip-13.sentence-1)

[🔗](#lib:showpos)

`ios_base& showpos(ios_base& str);
`

[14](#fmtflags.manip-14)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2507)

*Effects*: Callsstr.setf(ios_base​::​showpos)[.](#fmtflags.manip-14.sentence-1)

[15](#fmtflags.manip-15)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2512)

*Returns*: str[.](#fmtflags.manip-15.sentence-1)

[🔗](#lib:noshowpos)

`ios_base& noshowpos(ios_base& str);
`

[16](#fmtflags.manip-16)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2523)

*Effects*: Callsstr.unsetf(ios_base​::​showpos)[.](#fmtflags.manip-16.sentence-1)

[17](#fmtflags.manip-17)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2528)

*Returns*: str[.](#fmtflags.manip-17.sentence-1)

[🔗](#lib:skipws)

`ios_base& skipws(ios_base& str);
`

[18](#fmtflags.manip-18)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2539)

*Effects*: Callsstr.setf(ios_base​::​skipws)[.](#fmtflags.manip-18.sentence-1)

[19](#fmtflags.manip-19)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2544)

*Returns*: str[.](#fmtflags.manip-19.sentence-1)

[🔗](#lib:noskipws)

`ios_base& noskipws(ios_base& str);
`

[20](#fmtflags.manip-20)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2555)

*Effects*: Callsstr.unsetf(ios_base​::​skipws)[.](#fmtflags.manip-20.sentence-1)

[21](#fmtflags.manip-21)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2560)

*Returns*: str[.](#fmtflags.manip-21.sentence-1)

[🔗](#lib:uppercase)

`ios_base& uppercase(ios_base& str);
`

[22](#fmtflags.manip-22)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2571)

*Effects*: Callsstr.setf(ios_base​::​uppercase)[.](#fmtflags.manip-22.sentence-1)

[23](#fmtflags.manip-23)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2576)

*Returns*: str[.](#fmtflags.manip-23.sentence-1)

[🔗](#lib:nouppercase)

`ios_base& nouppercase(ios_base& str);
`

[24](#fmtflags.manip-24)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2587)

*Effects*: Callsstr.unsetf(ios_base​::​uppercase)[.](#fmtflags.manip-24.sentence-1)

[25](#fmtflags.manip-25)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2592)

*Returns*: str[.](#fmtflags.manip-25.sentence-1)

[🔗](#lib:unitbuf)

`ios_base& unitbuf(ios_base& str);
`

[26](#fmtflags.manip-26)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2603)

*Effects*: Callsstr.setf(ios_base​::​unitbuf)[.](#fmtflags.manip-26.sentence-1)

[27](#fmtflags.manip-27)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2608)

*Returns*: str[.](#fmtflags.manip-27.sentence-1)

[🔗](#lib:nounitbuf)

`ios_base& nounitbuf(ios_base& str);
`

[28](#fmtflags.manip-28)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2619)

*Effects*: Callsstr.unsetf(ios_base​::​unitbuf)[.](#fmtflags.manip-28.sentence-1)

[29](#fmtflags.manip-29)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2624)

*Returns*: str[.](#fmtflags.manip-29.sentence-1)

#### [31.5.5.2](#adjustfield.manip) adjustfield manipulators [[adjustfield.manip]](adjustfield.manip)

[1](#adjustfield.manip-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2631)

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

[🔗](#lib:internal)

`ios_base& internal(ios_base& str);
`

[2](#adjustfield.manip-2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2641)

*Effects*: Callsstr.setf(ios_base​::​internal, ios_base​::​adjustfield)[.](#adjustfield.manip-2.sentence-1)

[3](#adjustfield.manip-3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2646)

*Returns*: str[.](#adjustfield.manip-3.sentence-1)

[🔗](#lib:left)

`ios_base& left(ios_base& str);
`

[4](#adjustfield.manip-4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2657)

*Effects*: Callsstr.setf(ios_base​::​left, ios_base​::​adjustfield)[.](#adjustfield.manip-4.sentence-1)

[5](#adjustfield.manip-5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2662)

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

[🔗](#lib:right)

`ios_base& right(ios_base& str);
`

[6](#adjustfield.manip-6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2673)

*Effects*: Callsstr.setf(ios_base​::​right, ios_base​::​adjustfield)[.](#adjustfield.manip-6.sentence-1)

[7](#adjustfield.manip-7)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2678)

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

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

[1](#basefield.manip-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"))[.](#basefield.manip-1.sentence-1)

[🔗](#lib:dec)

`ios_base& dec(ios_base& str);
`

[2](#basefield.manip-2)

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

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

[3](#basefield.manip-3)

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

*Returns*: str[.](#basefield.manip-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](#basefield.manip-4)

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

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

[5](#basefield.manip-5)

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

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

[🔗](#lib:oct)

`ios_base& oct(ios_base& str);
`

[6](#basefield.manip-6)

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

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

[7](#basefield.manip-7)

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

*Returns*: str[.](#basefield.manip-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)

#### [31.5.5.4](#floatfield.manip) floatfield manipulators [[floatfield.manip]](floatfield.manip)

[1](#floatfield.manip-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2750)

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

[🔗](#lib:fixed)

`ios_base& fixed(ios_base& str);
`

[2](#floatfield.manip-2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2760)

*Effects*: Callsstr.setf(ios_base​::​fixed, ios_base​::​floatfield)[.](#floatfield.manip-2.sentence-1)

[3](#floatfield.manip-3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2765)

*Returns*: str[.](#floatfield.manip-3.sentence-1)

[🔗](#lib:scientific)

`ios_base& scientific(ios_base& str);
`

[4](#floatfield.manip-4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2776)

*Effects*: Callsstr.setf(ios_base​::​scientific, ios_base​::​floatfield)[.](#floatfield.manip-4.sentence-1)

[5](#floatfield.manip-5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2781)

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

[🔗](#lib:hexfloat)

`ios_base& hexfloat(ios_base& str);
`

[6](#floatfield.manip-6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2792)

*Effects*: Calls str.setf(ios_base​::​fixed | ios_base​::​scientific,
 ios_base​::​floatfield)[.](#floatfield.manip-6.sentence-1)

[7](#floatfield.manip-7)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2797)

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

[8](#floatfield.manip-8)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2802)

[*Note [1](#floatfield.manip-note-1)*:

ios_base​::​hex cannot be used to specify
a hexadecimal floating-point format,
because it is not part of ios_base​::​floatfield (Table [137](ios.fmtflags#tab:ios.fmtflags.const "Table 137: fmtflags constants"))[.](#floatfield.manip-8.sentence-1)

— *end note*]

[🔗](#lib:defaultfloat)

`ios_base& defaultfloat(ios_base& str);
`

[9](#floatfield.manip-9)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2816)

*Effects*: Calls str.unsetf(ios_base​::​floatfield)[.](#floatfield.manip-9.sentence-1)

[10](#floatfield.manip-10)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2820)

*Returns*: str[.](#floatfield.manip-10.sentence-1)