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From: Adam Beneschan <adam@irvine.com>
Newsgroups: comp.lang.ada
Subject: Re: Equivalent of dynamic_cast (downcast) for tagged types
Date: Thu, 27 Jan 2011 11:33:30 -0800 (PST)
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Date: 2011-01-27T11:33:30-08:00
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On Jan 27, 7:46=A0am, Maciej Sobczak <see.my.homep...@gmail.com> wrote:
> Hi,
>
> Unfortunately I need to HACK some equivalent of dynamic_cast in Ada.
>
> There is a limited tagged type T deriving from Limited_Controlled and
> Some_Interface as well.
> There is also a procedure like this:
>
> procedure Foo (X : in Some_Interface'Class);
>
> Inside Foo I would like to check if X is indeed T

   if X in T

> and if so, I would
> like to dynamic_cast to it and execute some operation on T.

     then Execute_Some_Operation_On (T(X));
   end if;

Wonderful, no?  In Ada you get to write pretty much what you were
thinking of doing.  The C++ equivalent is quite elegant, if you
consider the number of ugly punctuation characters and cryptically-
named built-in identifiers to be a measure of elegance.

                             -- Adam