std::showbase, std::noshowbase

From cppreference.com
< cpp‎ | io‎ | manip
Defined in header <ios>
std::ios_base& showbase( std::ios_base& str );
(1)
std::ios_base& noshowbase( std::ios_base& str );
(2)

1) enables the showbase flag in the stream str as if by calling str.setf(std::ios_base::showbase)

2) disables the showbase flag in the stream str as if by calling str.unsetf(std::ios_base::showbase)

This is an I/O manipulator, it may be called with an expression such as out << std::showbase for any out of type std::basic_ostream or with an expression such as in >> std::showbase for any in of type std::basic_istream.

The showbase flag affects the behavior of integer output (see std::num_put::put), monetary input (see std::money_get::get) and monetary output (see std::money_put::put).

Parameters

str - reference to I/O stream

Return value

str (reference to the stream after manipulation)

Notes

As specifed in std::num_put::put, the showbase flag in integer output acts like the # format specifier in std::printf, which means the numeric base prefix is not added when outputting the value zero.