std::ios_base::fmtflags - cppreference.com

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typedef/*implementation defined*/fmtflags;staticconstexprfmtflagsdec=/*implementation defined*/staticconstexprfmtflagsoct=/*implementation defined*/staticconstexprfmtflagshex=/*implementation defined*/staticconstexprfmtflagsbasefield=dec|oct|hex;staticconstexprfmtflagsleft=/*implementation defined*/staticconstexprfmtflagsright=/*implementation defined*/staticconstexprfmtflagsinternal=/*implementation defined*/staticconstexprfmtflagsadjustfield=left|right|internal;staticconstexprfmtflagsscientific=/*implementation defined*/staticconstexprfmtflagsfixed=/*implementation defined*/staticconstexprfmtflagsfloatfield=scientific|fixed;staticconstexprfmtflagsboolalpha=/*implementation defined*/staticconstexprfmtflagsshowbase=/*implementation defined*/staticconstexprfmtflagsshowpoint=/*implementation defined*/staticconstexprfmtflagsshowpos=/*implementation defined*/staticconstexprfmtflagsskipws=/*implementation defined*/staticconstexprfmtflagsunitbuf=/*implementation defined*/staticconstexprfmtflagsuppercase=/*implementation defined*/Specifies available formatting flags. It is a

BitmaskType

. The following constants are defined:

Constant Explanation

dec

use decimal base for integer I/O: see

std::dec

oct

use octal base for integer I/O: see

std::oct

hex

use hexadecimal base for integer I/O: see

std::hex

basefield

dec|oct|hex. Useful for masking operations

left

left adjustment (adds fill characters to the right): see

std::left

right

right adjustment (adds fill characters to the left): see

std::right

internal

internal adjustment (adds fill characters to the internal designated point): see

std::internal

adjustfield

left|right|internal. Useful for masking operations

scientific

generate floating point types using scientific notation, or hex notation if combined with fixed: see

std::scientific

fixed

generate floating point types using fixed notation, or hex notation if combined with scientific: see

std::fixed

floatfield

scientific|fixed. Useful for masking operations

boolalpha

insert and extract bool type in alphanumeric format: see

std::boolalpha

showbase

generate a prefix indicating the numeric base for integer output, require the currency indicator in monetary I/O: see

std::showbase

showpoint

generate a decimal-point character unconditionally for floating-point number output: see

std::showpoint

showpos

generate a + character for non-negative numeric output: see

std::showpos

skipws

skip leading whitespace before certain input operations: see

std::skipws

unitbuf

flush the output after each output operation: see

std::unitbuf

uppercase

replace certain lowercase letters with their uppercase equivalents in certain output operations: see

std::uppercase

Example

The following example shows several different ways to print the same result.

Run this code

#include<iostream>intmain(){constintnum=150;// using fmtflags as class member constants:std::cout.setf(std::ios_base::hex,std::ios_base::basefield);std::cout.setf(std::ios_base::showbase);std::cout<<num<<'\n';// using fmtflags as inherited class member constants:std::cout.setf(std::ios::hex,std::ios::basefield);std::cout.setf(std::ios::showbase);std::cout<<num<<'\n';// using fmtflags as object member constants:std::cout.setf(std::cout.hex,std::cout.basefield);std::cout.setf(std::cout.showbase);std::cout<<num<<'\n';// using fmtflags as a type:std::ios_base::fmtflagsff;ff=std::cout.flags();ff&=~std::cout.basefield;// unset basefield bitsff|=std::cout.hex;// set hexff|=std::cout.showbase;// set showbasestd::cout.flags(ff);std::cout<<num<<'\n';// not using fmtflags, but using manipulators:std::cout<<std::hex<<std::showbase<<num<<'\n';}Output:

0x96 0x96 0x96 0x96 0x96 See also

flags

manages format flags
(public member function)

[edit]

setf

sets specific format flag
(public member function)

[edit]

unsetf

clears specific format flag
(public member function)

[edit]

setbase

changes the base used for integer I/O
(function)