Re: What's the difference between...

[kronos.arc.nasa.gov!butch!LMSC5.IS.LMSC.LOCKHEED.COM!LJ10891@ames.arc.nas]

------------------------- Original Article -------------------------
>type Placement is range 0 .. 10;
>subtype Placement is INTEGER range 0 .. 10;

  I'm no maven, but I'll give it a shot.

  The first declaration defines a new type whose base type is the infamous
{anonymous integer}.  The second declaration defines a subtype whose base
type is the named type STANDARD.INTEGER.  This subtype inherits all of
the operations defined on its parent type.

   Illustrative example:

X : INTEGER := 5;
P1 : PLACEMENT_1 := 6;
P2 : PLACEMENT_2 := 6;

begin
  X := P1 + 3;  --illegal: result type is PLACEMENT_1
  P1 := X + 3;  --illegal: result type is INTEGER
  P2 := X + 3;  --legal
  P2 := X + 6;  --CONSTRAINT_ERROR
end;

   Hope that helps.  Send comments to ghaddad@lunacity.com.  Send flames
to someone@who.needs.them.

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