std::ios_base::setf

fmtflags setf( fmtflags flags );	(1)
fmtflags setf( fmtflags flags, fmtflags mask );	(2)

Sets the formatting flags to specified settings.

1) Sets the formatting flags identified by flags. Effectively the following operation is performed fl = fl | flags where fl defines the state of internal formatting flags.

2) Clears the formatting flags under mask, and sets the cleared flags to those specified by flags. Effectively the following operation is performed fl = (fl & ~mask) | (flags & mask) where fl defines the state of internal formatting flags.

Parameters

flags, mask

new formatting setting. mask defines which flags can be altered, flags defines which flags of those to be altered should be set (others will be cleared). Both parameters can be a combination of the following constants:

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`

Return value

the formatting flags before the call to the function.

Example

#include <iostream>
#include <iomanip>
 
const double PI = 3.1415926535;
 
int main() 
{
    const int WIDTH = 15;
 
    std::cout.setf(std::ios::right);  //equivalent: cout << right;
    std::cout << std::setw(WIDTH/2) << "radius"
              << std::setw(WIDTH) << "circumference" << '\n';
 
    std::cout.setf(std::ios::fixed);
    for (double radius = 1; radius <= 6; radius += 0.5) {
        std::cout << std::setprecision(1) << std::setw(WIDTH/2) 
                  << radius
                  << std::setprecision(2) << std::setw(WIDTH) 
                  << (2 * PI * radius) << '\n';
    }
}

Output:

radius  circumference
    1.0           6.28
    1.5           9.42
    2.0          12.57
    2.5          15.71
    3.0          18.85
    3.5          21.99
    4.0          25.13
    4.5          28.27
    5.0          31.42
    5.5          34.56
    6.0          37.70

flags	manages format flags (public member function)
unsetf	clears specific format flag (public member function)

std::ios_base::setf

Parameters

Return value

Example

See also