1. -- 
  2. -- Uwe R. Zimmer, Australia, 2013 
  3. -- 
  4.  
  5. package body Queue_Pack_Exceptions is 
  6.  
  7.    procedure Enqueue (Item : Element; Queue : in out Queue_Type) is 
  8.  
  9.    begin 
  10.       if Is_Full (Queue) then 
  11.          raise Queue_overflow; 
  12.       end if; 
  13.       Queue.Elements (Queue.Free) := Item; 
  14.       Queue.Free     := Marker'Succ (Queue.Free); 
  15.       Queue.Is_Empty := False; 
  16.    end Enqueue; 
  17.  
  18.    procedure Dequeue (Item : out Element; Queue : in out Queue_Type) is 
  19.  
  20.    begin 
  21.       if Is_Empty (Queue) then 
  22.          raise Queue_underflow; 
  23.       end if; 
  24.       Item           := Queue.Elements (Queue.Top); 
  25.       Queue.Top      := Marker'Succ (Queue.Top); 
  26.       Queue.Is_Empty := Queue.Top = Queue.Free; 
  27.    end Dequeue; 
  28.  
  29. end Queue_Pack_Exceptions;