std::showpoint,std::noshowpoint (3) - Linux Manuals
Defined in header <ios>
std::ios_base& showpoint( std::ios_base& str ); (1)
std::ios_base& noshowpoint( std::ios_base& str ); (2)
Enables or disables the unconditional inclusion of the decimal point character in floating-point output. Has no effect on input.
1) enables the showpoint flag in the stream str as if by calling str.setf(std::ios_base::showpoint)
2) disables the showpoint flag in the stream str as if by calling str.unsetf(std::ios_base::showpoint)
This is an I/O manipulator, it may be called with an expression such as out << std::showpoint for any out of type std::basic_ostream or with an expression such as in >> std::showpoint for any in of type std::basic_istream.
The character to use as decimal point character is determined by the numpunct facet of the locale imbued in the stream at the time of output, as described in std::num_put::put
str - reference to I/O stream
str (reference to the stream after manipulation)
// Run this code