NAME¶

std::resetiosflags - std::resetiosflags

Synopsis¶

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

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

Parameters¶

mask - bitmask of the flags to clear

Return value¶

An object of unspecified type such that

* if out is an object of type std::basic_ostream<CharT, Traits>, the expression
out << resetiosflags(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
>> resetiosflags(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)
{
// reset specified flags
str.setf(ios_base::fmtflags(0), mask);
}

Example¶

// Run this code

#include <iomanip>
#include <iostream>
#include <sstream>

int main()
{
std::istringstream in("10 010 10 010 10 010");
int n1, n2;

in >> std::oct >> n1 >> n2;
std::cout << "Parsing \"10 010\" with std::oct gives: " << n1 << ' ' << n2 << '\n';

in >> std::dec >> n1 >> n2;
std::cout << "Parsing \"10 010\" with std::dec gives: " << n1 << ' ' << n2 << '\n';

in >> std::resetiosflags(std::ios_base::basefield) >> n1 >> n2;
std::cout << "Parsing \"10 010\" with autodetect gives: " << n1 << ' ' << n2 << '\n';
}

Output:¶

Parsing "10 010" with std::oct gives: 8 8
Parsing "10 010" with std::dec gives: 10 10
Parsing "10 010" with autodetect gives: 10 8

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

See also¶

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