std::basic_ostream<CharT,Traits>::put (3) - Linux Man Pages
basic_ostream& put( char_type ch );
Behaves as an UnformattedOutputFunction. After constructing and checking the sentry object, writes the character ch to the output stream.
If the output fails for any reason, sets badbit.
ch - character to write
This function is not overloaded for the types signed char or unsigned char, unlike the formatted operator<<
Unlike formatted output functions, this function does not set the failbit if the output fails.
// Run this code
operator<<(std::basic_ostream) (function template)
write (public member function)