practice returning a dynamically allocated array

unchecked_deallocation_experiment.adb

with Ada.Text_IO; use Ada.Text_IO;
with Ada.Command_Line;
with Ada.Unchecked_Deallocation;

package body Dynamic_Allocation_Experiment 
is
   type Side is (Left, Right);
   type Side_Array is array (Integer range <>) of Side;
   type Side_Array_Ptr is access Side_Array;

   procedure Free_Side_Array is
    new Ada.Unchecked_Deallocation(Side_Array, Side_Array_Ptr);

   function Make_Sides (Size : Natural) return Side_Array_Ptr
   is
   begin
      declare
         Sides_Ptr : Side_Array_Ptr := new Side_Array (1 .. Size);
         Toggle : Boolean := True;
      begin
         for I in Sides_Ptr'Range loop
            Sides_Ptr (I) := (if Toggle then Right else Left);
            Toggle := not Toggle;
         end loop;
         return Sides_Ptr;
      end;
   end Make_Sides;

   procedure Dump_Sides (S : Side_Array_Ptr) is
   begin
      for I in S'Range loop
         Ada.Text_IO.Put_Line (Side'Image (S (I)));
      end loop;
   end Dump_Sides;

   procedure Dynamic_Allocation_Experiment 
   is
      S : Side_Array_Ptr;
      Arg1 : String := Ada.Command_Line.Argument (1);
      Size : Integer := Integer'Value (Arg1);
   begin
      S := Make_Sides (Size);
      Dump_Sides (S);
      Ada.Text_IO.Put_Line ("len: " & Integer'Image (S'Length));
      Free_Side_Array (S);
   end Dynamic_Allocation_Experiment;
end Dynamic_Allocation_Experiment;