Objects of the iostream class can be constructed and destructed.
public:virtual ~iostream()
This is supported on

Destructs an iostream object.
public:iostream(streambuf*)
This is supported on

This constructor takes a single streambuf argument and creates an iostream object that is attached to the streambuf object. The constructor also initializes the format variables to their defaults.
protected:iostream()
This is supported on

Protected contructor.