C++ attributes can be described using four basic fields: the target they can be applied to (Applies To), if they are repeatable or not (Repeatable), the required presence of other attributes (Required Attributes), and incompatibilities with other attributes (Invalid Attributes). These fields are listed in an accompanying table in each attribute's reference topic. Each of these fields is described below.
This field describes the different C++ language elements that are legal targets for the specified attribute. For instance, if an attribute specifies "class" in the Applies To field, this indicates that the attribute can only be applied to a legal C++ class. If the attribute is applied to a member function of a class, a syntax error would result.
For more information, see Attributes by Usage.