From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,a84a01d2859560a0
X-Google-Attributes: gid103376,public
From: "David C. Hoos, Sr." <david.c.hoos.sr@ada95.com>
Subject: Re: bit operations on integers
Date: 1999/05/03
Message-ID: <7gkr2g$k5g@hobbes.crc.com>#1/1
X-Deja-AN: 473684481
References: <7gkhr7$5kr$1@nnrp1.dejanews.com>
Organization: Coleman Research Corporation
X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3612.1700
Newsgroups: comp.lang.ada
Date: 1999-05-03T00:00:00+00:00
List-Id: <comp.lang.ada>


phadreus@iname.com wrote in message <7gkhr7$5kr$1@nnrp1.dejanews.com>...
>
>
>How do I test, set, and clear individual bits in an integer
>in Ada 83?
>
How about:

package Bit_Ops is

   function Test
     (Item : Integer;
      N    : Natural)
      return Boolean;

   procedure Set
     (Item : in out Integer;
      N    :        Natural);

   procedure Clear
     (Item : in out Integer;
      N    :        Natural);

end Bit_Ops;

package body Bit_Ops is

   type Bit_Array is
      array (Natural range 0 .. Integer'Size - 1)
     of Boolean;
   pragma Pack (Bit_Array);


   -----------
   -- Clear --
   -----------

   procedure Clear
     (Item : in out Integer;
      N    :        Natural)
   is
     Bits : Bit_Array;
     for Bits use at Item'Address;
   begin
      Bits (N) := False;
   end Clear;

   ---------
   -- Set --
   ---------

   procedure Set
     (Item : in out Integer;
      N    :        Natural)
   is
     Bits : Bit_Array;
     for Bits use at Item'Address;
   begin
      Bits (N) := True;
   end Set;

   ----------
   -- Test --
   ----------

   function Test
     (Item : Integer;
      N    : Natural)
      return Boolean
   is
     Bits : Bit_Array;
     for Bits use at Item'Address;
   begin
      return Bits (N);
   end Test;

end Bit_Ops;