std::setiosflags

 

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Defined in header <iomanip>
/*unspecified*/ setiosflags( std::ios_base::fmtflags mask );

When used in an expression out << setiosflags(mask) or in >> setiosflags(mask), sets all format flags of the stream out or in as specified by the mask.

Parameters

mask

-

bitmask of the flags to set

Return value

An object of unspecified type such that

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

where the function f is defined as:

void f(std::ios_base& str, std::ios_base::fmtflags mask)
{
    // set specified flags
    str.setf(mask);
}

Example

Run this code

#include <iomanip>
#include <iostream>
 
int main()
{
    std::cout << std::resetiosflags(std::ios_base::dec) 
              << std::setiosflags(  std::ios_base::hex
                                  | std::ios_base::uppercase
                                  | std::ios_base::showbase) << 42 << '\n';
}

Output:

0X2A

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	setiosflags could only be used with streams of type std::ostream or std::istream	usable with any character stream

See also

setf	sets specific format flag (public member function of std::ios_base)
resetiosflags	clears the specified ios_base flags (function)