Determines if the underlying value is None.
Determines if the underlying value is None,
or the predicate using the Some value is true.
Determines if the underlying value is something.
Determines if the underlying value is something, and the predicate using that same value is also true.
Unwrap the underlying value and returns it.
If the value is None then this function
will throw an error.
Unwraps the underlying value, or returns the given
value if the underlying value is None.
Represents a thing that may or may not have a value.
Very useful when dealing with things that might be null or undefined.
Example