< cpp‎ | io‎ | manip
Input/output manipulators
Floating-point formatting
Integer formatting
Boolean formatting
Field width and fill control
Other formatting
Whitespace processing
Output flushing

Status flags manipulation
Time and money I/O
Quoted manipulator
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.


[edit] Parameters

mask - bitmask of the flags to set

[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 << 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

[edit] Example

#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';



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

[edit] See also

sets specific format flag
(public member function of std::ios_base) [edit]
clears the specified ios_base flags
(function) [edit]