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From: 18k11tm001@sneakemail.com (Russ)
Newsgroups: comp.lang.ada
Subject: Re: Ideas for Ada 200X
Date: 6 Jun 2003 10:15:29 -0700
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Stephen Leake <Stephe.Leake@nasa.gov> wrote in message news:<uznkwflx8.fsf@nasa.gov>...

> procedure Matrix_Add
>    (Target : in out Matrix_Type; 
>     Addend : in Matrix_type);
> procedure "+=" (...) renames Matrix_Add;
> 
> 
> A += B;
> 
> the compiler actually does:
> 
> C = A;
> Matrix_Add (C, B);
> A = C;
> 
> I suppose you could change that rule, but that would be a bigger
> change to the language, since "A += B" would no longer be identical to
> "A := A + B".

You seem to be going around in circles here. The whole idea was that A
+= B can avoid the temporary matrix and the extra copy operation.
That's how it works in C++. Without that benefit, yes you might as
well just use A := A + B.