std::setfill

 

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Defined in header <iomanip>
template< class CharT > /*unspecified*/ setfill( CharT c );

When used in an expression out << setfill(c) sets the fill character of the stream out to c.

Parameters

c

-

new value for the fill character

Return value

An object of unspecified type such that

• if out is an object of type std::basic_ostream<CharT, Traits>, the expression out << setfill(c)
  • has type std::basic_ostream<CharT, Traits>&
  • has value out
  • behaves as if it called f(out, c)

where the function f is defined as:

template<class CharT, class Traits>
void f(std::basic_ios<CharT, Traits>& str, CharT c)
{
    // set fill character
    str.fill(c);
}

Notes

The current fill character may be obtained with std::ostream::fill.

Example

Run this code

#include <iostream>
#include <iomanip>
 
int main()
{
    std::cout << "default fill: [" << std::setw(10) << 42 << "]\n"
              << "setfill('*'): [" << std::setfill('*')
                                   << std::setw(10) << 42 << "]\n";
}

Output:

default fill: [        42]
setfill('*'): [********42]

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 183	C++98	setbase could only be used with streams of type std::ostream	usable with any output character stream

See also

fill	manages the fill character (public member function of std::basic_ios<CharT,Traits>)
internalleftright	sets the placement of fill characters (function)
setw	changes the width of the next input/output field (function)