From cppreference.com
template<classCharT>/*unspecified*/setfill(CharTc);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<classCharT,classTraits>voidf(std::basic_ios<CharT,Traits>&str,CharTc){// set fill characterstr.fill(c);}Notes
The current fill character may be obtained with
.
Example
Run this code
#include<iomanip>#include<iostream>intmain(){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
C++98 setbase could only be used with
streams of type
usable with any output
character stream See also
manages the fill character
(public member function of std::basic_ios<CharT,Traits>)
sets the placement of fill characters
(function)
changes the width of the next input/output field
(function)