Answer:
The description for the given question is described in the explanation section below.
Step-by-step explanation:
In reality, the "!" operator remains overloaded throughout the library of IO-stream, which effectively comes back the contrary feature of good.
It's how that they would load the "!" operator to construct a unary member overloading feature.
Example:
class abc
{
public :
bool isValid ( ) // return true
bool operator ! ( ) // return isValid( )
};
Optionally, to overwhelm the unary, you may build a global feature "!" user.