std::ios_base::fmtflags

static constexpr fmtflags showbase = /*implementation defined*/
static constexpr fmtflags showpoint = /*implementation defined*/
static constexpr fmtflags showpos = /*implementation defined*/
static constexpr fmtflags skipws = /*implementation defined*/
static constexpr fmtflags unitbuf = /*implementation defined*/

static constexpr fmtflags uppercase = /*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

[edit] Example

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

Run this code

#include <iostream>
 
int main()
{
 const int num = 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::fmtflags ff;
 ff = std::cout.flags();
 ff &= ~std::cout.basefield; // unset basefield bits
 ff |= std::cout.hex; // set hex
 ff |= std::cout.showbase; // set showbase
 std::cout.flags(ff);
 std::cout << num << '\n';
 
 // not using fmtflags, but using manipulators:
 std::cout << std::hex << std::showbase << num << '\n';
}