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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: This can't be done in Ada...or?
Date: 17 Feb 2005 21:52:45 +0000
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Date: 2005-02-17T21:52:45+00:00
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Robert A Duff <bobduff@shell01.TheWorld.com> writes:

> This Reflection package has a bunch of string manipulation code,
> and if you instantiate it in a procedure, it will happen
> every time that procedure is called (unless the compiler
> is smarter than I think it is).  This could indeed be very
> costly.

The output of

   with Ada.Text_IO; use Ada.Text_IO;
   with BC.Support.High_Resolution_Time;
   with PragmaRC.Reflection;

   procedure Refl is

      use type BC.Support.High_Resolution_Time.Time;

      Start, Finish : BC.Support.High_Resolution_Time.Time;

   begin

      Start := BC.Support.High_Resolution_Time.Clock;

      declare
         package R is new PragmaRC.Reflection;
      begin
         null;
      end;

      Finish := BC.Support.High_Resolution_Time.Clock;

      Put_Line ("took " & Duration'Image (Finish - Start));

   end Refl;
 
here (gnatmake -O2, gnat 5.02a1 i686-pc-linux-gnu) is

   smaug.pushface.org[13]$ ./refl
   Clock rate is 0.400914522 GHz
   took  0.000023852

-- 
Simon Wright                               100% Ada, no bugs.