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function EmptyParam: OleVariant;


Type Visibility Source Unit Parent
function public System.Variants.pas System.Variants System.Variants


Contains an OleVariant that represents an unused optional parameter on a dual interface.

EmptyParam can be used for Variants that represent optional parameters whose value is unassigned. This is useful when the code that marshals method calls requires a fixed number of parameters, even if some of them are optional.

When marshaling interface calls that include optional parameters, COM requires a value for those parameters even when they are not used. EmptyParam returns an OleVariant you can pass as that value to indicate that the parameter is not used.

See Also