Overloaded Operators Can Be Used to Test a Stream's State

Multiple Choice

Overloaded operators can be used to test a stream's state in conditions. The operator! member function, inherited into the stream classes from class basic_ios, returns true if the badbit, the failbit or both are true. The ________ member function (added in C++11) returns false if the badbit is true, the failbit is true or both are true.

A) operator boolalpha
B) operator!
C) operator boolean
D) operator bool