std::boolalpha, std::noboolalpha - cppreference.com (original) (raw)
| Defined in header | | | | ----------------------------------------------------------------------------------------------- | --- | | | std::ios_base& boolalpha( std::ios_base& str ); | (1) | | | std::ios_base& noboolalpha( std::ios_base& str ); | (2) | |
Enables the
boolalphaflag in the stream str as if by calling str.setf(std::ios_base::boolalpha).Disables the
boolalphaflag 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.
[edit] Parameters
| str | - | reference to I/O stream |
|---|
[edit] Return value
str (reference to the stream after manipulation).
[edit] Example
#include #include int main() { // boolalpha output std::cout << "default true: " << true << '\n' << "default false: " << false << '\n' << std::boolalpha << "boolalpha true: " << true << '\n' << "boolalpha false: " << false << '\n' << 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: " << std::boolalpha << b1 << ' ' << b2 << '\n'; }
Output:
default true: 1 default false: 0 boolalpha true: true boolalpha false: false noboolalpha true: 1 noboolalpha false: 0 "true false" parsed as: true false