Equal compares two nullable values and returns true if they are equal.

From a value which is considered 'set'.

FromCond conditionally creates a 'set' value if the bool is true, else it will return a null value.

FromPtr creates a value from a pointer, if the pointer is null it will be 'null', if it has a value the deferenced value is stored.

Map transforms the value inside if it is set, else it returns a value of the same state.

Val allows representing a value with a state of "null" or "set".