Ada Reference Manual — Legal Information

12.5.5 Formal Interface Types

1/2

The category determined for a formal interface type is the category of all interface types.

Syntax

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formal_interface_type_definition ::= interface_type_definition

Legality Rules

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The actual type shall be a descendant of every progenitor of the formal type.

4/2

The actual type shall be a limited, task, protected, or synchronized interface if and only if the formal type is also, respectively, a limited, task, protected, or synchronized interface.

Examples

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type Root_Work_Item is tagged private;

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generic
   type Managed_Task is task interface;
   type Work_Item(<>) is new Root_Work_Item with private;
package Server_Manager is
   task type Server is new Managed_Task with
      entry Start(Data : in out Work_Item);
   end Server;
end Server_Manager;

7/2

This generic allows an application to establish a standard interface that all tasks need to implement so they can be managed appropriately by an application-specific scheduler.