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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Extended return question
Date: Thu, 10 Jul 2008 18:20:11 -0500
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Date: 2008-07-10T18:20:11-05:00
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"Dale Stanbrough" <MrNoSpam@bigpoop.net.au> wrote in message 
news:MrNoSpam-BCD9C2.17322110072008@news-server.bigpond.net.au...
> Georg Bauhaus wrote:
>
>> Dale Stanbrough wrote:
>> > The purpose of an extended return is to create the values in-situ
>> > without copying.
>>
>> _Limited_ objects can be initialized in situ by an aggregate
>> or function call  ... :-)
>
>
> Ah, thanks.  I had misread John Barnes comments on this. Why such a
> restriction? Why not allow it for all extended returns on all types?

Build-in-place is *allowed* for all objects; it is only *required* for types 
that always have to be limited (now known as "immutably limited types" (see 
AI05-0052-1).

The reason it is not required is that the function could be used in an 
assignment statement, and in that case, it doesn't make sense to require 
build-in-place. And trying to have a function that works both ways could be 
expensive to implement (the calling conventions are very different).

                                 Randy.