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From: Martin Krischik <krischik@users.sourceforge.net>
Newsgroups: comp.lang.ada
Subject: Re: memory management and productivity
Date: Mon, 21 Jun 2004 18:47:45 +0200
Organization: AdaCL
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Date: 2004-06-21T18:47:45+02:00
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Hyman Rosen wrote:

> Martin Krischik wrote:
>> For example C++ std::vector<> can't store polymorvic objects - Ada soon
>> to come Ada.Containers.Indefinite_Vectors can.
> 
> That seems like a neat trick, given that a vector is
> intended to work like an array,
> that is, to have a 
> contiguous block of equal-sized objects.

It only has to work like it - internally it might be implemented differently
i.E. using dynamic memory.

> How is the 
> container going to work?

The trick is that Ada can "clone ()" objects without:

class Base
{
   virtual Base* clone();
}

That's because Ada knows (by hidden size attribute) how large any object is.
Including polymorvic objects. Write any indefinite object to a Stream via
'Output and look at it with hex editor.

In that respect Ada is even cooler then Java: You can serialise any object
without a Serialiseable interface.

So, the truth is that the object is copied into dynamic memory. However, you
will never know about it.

With Regards

Martin

-- 
mailto://krischik@users.sourceforge.net
http://www.ada.krischik.com