Ada Programming/Attributes/'Tag

Attributes 'Tag __TOC__ Description X'Tag is an Ada attribute where X is any tagged type. This attribute returns a value of the private type Ada Tags.Tag which identifies the tagged type. This attribute is useful to check for membership of a type in a class hierarchy. It can also be used if it is known the type is in a class hierarchy and type-specific processing must take place. Example Ref : My_Tagged_Type_Reference; ... if Ref.all in My_Tagged_Type'Class then The object pointed at by Ref is in class hierarchy that is rooted at My_Tagged_Type. if Ref.all'Tag = My_Tagged_Type'Tag then Object is of type My_Tagged_Type. else Object is of some other type in the hierarchy. end if; else Object is not in the class hierarchy rooted at My_Tagged_Type (it might be of a progenitor type though). end if; See also Wikibook Ada Programming Ada Programming/Object Orientation Ada Programming/Attributes/'Class Ada Reference Manual 13 3 Operational and Representation Attributes K Language-Defined Attributes Tag