std::resetiosflags
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resetiosflags
(C++14)
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.
[edit] Parameters
mask
-
bitmask of the flags to clear
[edit] 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); }
[edit] 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
[edit] 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 withstreams of type std::ostream or std::istream |
usable with any character stream |