<iomanip>
Include the iostreams standard header <iomanip> to define several manipulators that each take a single argument.
For a list of all members of this header, see <iomanip> Members.
#include <iomanip>
Remarks
Each of these manipulators returns an unspecified type, called T1 through T10, that overloads both basic_istream<Elem, Tr>::operator>> and basic_ostream<Elem, Tr>::operator<<.
See Also
Reference
Thread Safety in the Standard C++ Library