gcc/testsuite/gnat.dg/sync_iface_test.ads

   1 package Sync_Iface_Test is
   2    type Iface is limited interface;
   3    function First (Obj : Iface) return Natural is abstract;
   4
   5    protected type Buffer is new Iface with
   6       procedure Dummy;
   7    end;
   8    overriding function First (Obj : Buffer) return Natural;
   9
  10    procedure Do_Test (Dummy : Natural; Item  : Buffer);
  11 end;