A Class defines a classification over a set of object instances by defining the behavior they exhibit. This behavior is represented through operations, attributes, references, participation in associations, nested classes, constants, and constraints. Although the same or similar elements are used in other environments for representing Classes and their implementations, in the MOF these elements specify the class characteristics in an implementation-independent manner. For instance, defining a Class as having an attribute does not require the implementation of the Class (the software which provides the conformant behavior) to have an attribute, to hold the attribute value, etc. The implementation simply must insure that the behavior conforms to the definition of the attribute. The use of all the additional elements beyond operations provides a much richer environment for defining Class Behavior. Likewise, this construct is not an interface. Its expressibility goes beyond interface representations. The MOF's IDL translation capabilities map a single Class onto two interfaces. It would be possible to define transformations to alternate interface presentations, such as Java's interfaces.

There are, and probably always will be, divergent views among industry leaders on the definition of the concepts of Class, Type, and Interface. As a domain-specific modeling environment, so long as the MOF is clear about the meaning of Class within the MOF, it should remain immune from such concerns.

Attributes
Primitive Type boolean	isSingleton	When isSingleton is true, at most one M1 level instance of this Class may exist within the M1-level extent of the Class.

 isSingleton

public Primitive Type boolean isSingleton

When isSingleton is true, at most one M1 level instance of this Class may exist within the M1-level extent of the Class.

Properties:

Aggregation	none
Alias
Association
Association End
Class	Class Class
Collections
Datatype
Default
Default Value
Is Composite	false
Is Derived	false
Is Derived Union	false
Is Leaf	false
Is Ordered	false
Is Read Only	false
Is Static	false
Is Unique	true
Keywords
Lower	1
Lower Value
Multiplicity	1
Name	isSingleton
Name Expression
Opposite
Owned Template Signature
Owner	Class Class
Owning Association
Owning Parameter
Qualified Name	model1::model1::Class::isSingleton
Stereotype
Template Parameter
Type	Primitive Type boolean
Upper	1
Upper Value
Visibility	public

• A Class defines a classification over a set of object instances by defining the behavior they exhibit. This behavior is represented through operations, attributes, references, participation in associations, nested classes, constants, and constraints. Although the same or similar elements are used in other environments for representing Classes and their implementations, in the MOF these elements specify the class characteristics in an implementation-independent manner. For instance, defining a Class as having an attribute does not require the implementation of the Class (the software which provides the conformant behavior) to have an attribute, to hold the attribute value, etc. The implementation simply must insure that the behavior conforms to the definition of the attribute. The use of all the additional elements beyond operations provides a much richer environment for defining Class Behavior. Likewise, this construct is not an interface. Its expressibility goes beyond interface representations. The MOF's IDL translation capabilities map a single Class onto two interfaces. It would be possible to define transformations to alternate interface presentations, such as Java's interfaces.

  
  There are, and probably always will be, divergent views among industry leaders on the definition of the concepts of Class, Type, and Interface. As a domain-specific modeling environment, so long as the MOF is clear about the meaning of Class within the MOF, it should remain immune from such concerns.