-- File:	StepBasic_Unit.cdl
-- Created:	Wed Sep  8 13:38:07 1999
-- Author:	Andrey BETENEV
--		<abv@doomox.nnov.matra-dtv.fr>
---Copyright:	 Matra Datavision 1999


class Unit from StepBasic inherits SelectType from StepData

    ---Purpose: Implements a select type unit (NamedUnit or DerivedUnit)

uses
    NamedUnit from StepBasic,
    DerivedUnit from StepBasic

is
    Create returns Unit;
    	---Purpose: Creates empty object
	
    CaseNum (me; ent : Transient) returns Integer;
	---Purpose : Recognizes a type of Unit Entity
        --        1 -> NamedUnit
        --        2 -> DerivedUnit

    NamedUnit (me) returns any NamedUnit from StepBasic;
        ---Purpose : returns Value as a NamedUnit (Null if another type)

    DerivedUnit (me) returns any DerivedUnit from StepBasic;
        ---Purpose : returns Value as a DerivedUnit (Null if another type)

end Unit;