Reference notions

Definition

Local variables, operation parameters and class and instance attributes whose type is neither a basic class nor a set, are references towards the objects concerned. A reference is empty if it does not refer to any object.

The notVoid service can be used to test whether or not a reference is empty.

Example:

if (notVoid (ref))

//non empty reference

...else

//empty reference

Note: A void service, which carries out the opposite operation, also exists.