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From: "Jeff Creem" <jcreem@atetola.mv.com>
Subject: Re: question about functions (bis)
Date: 2000/01/21
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References: <8690s0$8tq$1@news.mgn.net> <38883285.AB6ED64C@gecm.com>
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Philip Anderson <phil.anderson@gecm.com> wrote in message
news:38883285.AB6ED64C@gecm.com...
> Pascal LEJEUNE wrote:
> >
> > function ADD (A, B : in T) return T is
> >    tmp : system.address;
> > begin
> >    << find the address of the result (that's my problem !!) >> and
> >    put it in a local variable (tmp)
> >
> >    call a procedure which use directly the hardware :
> >    proc (a'address, b'address, tmp);
> > end ADD;
> >
> > So, the problem is quite simple : the type T is a "numerical" type
> > on which it is normal to have operators ... but the hardware need
> > to have the address of the arguments and the address of the result !!!
>
>
> Can't you simply write:
>
> function ADD (A, B : in T) return T is
>    tmp : T;
> begin
>    -- call a procedure which directly uses the hardware :
>    --
>    proc (a'address, b'address, tmp'address);
>    return tmp;
> end ADD;
>



Which by the way when you do this, in certain cases, GNAT actually does not
even really create a new
variable tmp. In certain instances tmp is optimized out and 'address tmp =
'address of location of return
value.

(At least it looked that way to me compiling some test code on x86 and
looking at resulting code)
Jeff Creem