The application can register functions that take a reference to a variable type, which means that the function can receive a reference to a variable of any type. This is useful when making generic containers.
When a function is registered with this special parameter type, the function will receive both the reference and an extra argument with the type id of the variable type. The reference refers to the actual value that the caller sent, i.e. if the expression is an object handle then the reference will refer to the handle, not the actual object.
The variable type can also be used with
out references, but not with
inout references. Currently it can only be used with global functions, object constructors, and object methods. It cannot be used with other behaviours and operators.
The variable type is not available within scripts, so it can only be used to register application functions.
The variable parameter type can also be used in special versions of the opConv and opCast operator overloads. This is especially useful for generic container types that need to be able to hold any type of content.