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

Question

Quizplus · Accepted Answer

The operator bool member function is the best choice as it specifically returns true only if the stream is in a good state and false otherwise. This is more precise than the operator! function which returns true if the stream has any error state, including badbit and failbit. The other options, operator boolalpha and operator boolean, do not exist as member functions in the stream classes.

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