Testing no + operator add and swap

xor_alg.adb

-- Ported to Ada from https://www.geeksforgeeks.org/add-two-numbers-without-using-arithmetic-operators/

with Ada.Text_IO; use Ada.Text_IO;
with Interfaces;  use Interfaces;

procedure XOR_Alg is
   type Unsigned_Integer is mod 2 ** Integer'Size;

   function "xor" (Left, Right: Integer) return Integer is
   begin
      return Integer (Unsigned_Integer (Left) xor Unsigned_Integer (Right));
   end "xor";

   function "and" (Left, Right: Integer) return Integer is
   begin
      return Integer (Unsigned_Integer (Left) and Unsigned_Integer (Right));
   end "and";

   procedure Swap (X, Y : in out Unsigned_16) is
   begin
      if X /= Y then
         X := X xor Y;
         Y := Y xor X;
         X := X xor Y;
      end if;
   end Swap;

   function Add (X, Y : in Unsigned_16) return Unsigned_16 is
      A : Unsigned_16 := X;
      B : Unsigned_16 := Y;
      C : Unsigned_16;
   begin
      while B /= 0 loop
         C := A and B;
         A := A xor B;
         B := Shift_Left (C, 1);
      end loop;

      return A;
      -- return (X xor Y) or Shift_Left (X and Y, 1);
   end Add;

   function Add (X, Y : in Integer) return Integer is
      A : Integer := X;
      B : Integer := Y;
      C : Integer;
   begin
      while B /= 0 loop
         C := A and B;
         A := A xor B;
         B := Integer (Shift_Left (Unsigned_64 (C), 1));
      end loop;

      return A;
   end Add;

   A : Unsigned_16 := 56;
   B : Unsigned_16 := 98;
begin
   Swap (A, B);

   Put_Line ("A: " & Unsigned_16'Image (A) & "    B: " & Unsigned_16'Image (A));
   Put_Line ("A: " & Unsigned_16'Image (Add (32, 11)));
   Put_Line ("A: " & Unsigned_16'Image (Add (32, 15)));
   Put_Line ("A: " & Unsigned_16'Image (Add (80, -57)));
end XOR_Alg;