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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Return by reference
Date: Mon, 18 Dec 2017 16:41:54 -0600
Organization: JSA Research & Innovation
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Date: 2017-12-18T16:41:54-06:00
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"Mehdi Saada" <00120260a@gmail.com> wrote in message 
news:4d13b387-b813-449f-93b1-850822560578@googlegroups.com...
> Not like they were omnicient, but people in ARG certainly had at least
> some reasons to provide a "clunky" mechanism ?

Surely.  Every mechanism that we tried ended up simply regressing the 
problem -- there still was a non-user-defined dereference involved. And that 
had to be controlled, lest one be able to make long-lived copies of the 
dereferenced access type. It turned out that access discriminants have the 
right lifetime to do the control, and making the type with an access 
discriminant controlled gives the necessary hook. So it was much less change 
than a new kind of function return that really didn't solve the problem 
anyway.

Dmitry's delegation scheme would have worked, I guess, but such things can't 
replace assignment because they don't make sense for discriminant-dependent 
components. So you'd lose the assignment syntax, or have a horrible wart in 
the way it works.

                                     Randy.