std::boolalpha,std::noboolalpha (3) Linux Manual Page

std::boolalpha,std::noboolalpha – std::boolalpha,std::noboolalpha

Synopsis

Defined in header <ios>
std::ios_base& boolalpha( std::ios_base& str ); (1)
std::ios_base& noboolalpha( std::ios_base& str ); (2)
1) Enables the boolalpha flag in the stream str as if by calling str.setf(std::ios_base::boolalpha)
2) Disables the boolalpha flag in the stream str as if by calling str.unsetf(std::ios_base::boolalpha)
std::boolalpha is an I/O manipulator, so it may be called with an expression such as out << std::boolalpha for any out of type std::basic_ostream or with an expression such as in >> std::boolalpha for any in of type std::basic_istream.

Parameters

str – reference to I/O stream

Return value

str (reference to the stream after manipulation)

Example

// Run this code

#include <sstream>

#include <locale>

#include <iostream>

int main()

{
    // boolalpha output
    std::cout << std::boolalpha
              << "boolalpha true: " << true << '\n'
              << "boolalpha false: " << false << '\n';
    std::cout << std::noboolalpha
              << "noboolalpha true: " << true << '\n'
              << "noboolalpha false: " << false << '\n';
    // boolalpha parse
    bool b1, b2;
    std::istringstream is("true false");
    is >> std::boolalpha >> b1 >> b2;
    std::cout << '\"' << is.str() << "\" parsed as " << b1 << ' ' << b2 << '\n';
}

Output:

  boolalpha true: true
  boolalpha false: false
  noboolalpha true: 1
  noboolalpha false: 0
  "true false" parsed as 1 0

See also

              clears the specified ios_base flags
resetiosflags (function)
              sets the specified ios_base flags
setiosflags (function)
do_truename provides the string to use as the name of the boolean true and false
do_falsename (virtual protected member function of std::numpunct<CharT>)
[virtual]