From: Matthew Heaney <matthew_heaney@acm.org>
Subject: Re: Help - Constructors - ASAP.
Date: 1998/08/01
Date: 1998-08-01T00:00:00+00:00 [thread overview]
Message-ID: <m3r9z1vej5.fsf@mheaney.ni.net> (raw)
In-Reply-To: dewar.901945508@merv
dewar@merv.cs.nyu.edu (Robert Dewar) writes:
> <<But, a naieve reader would look at that and think that they could
> get back an object of *any* type in the class (as I have just proven
> :-) ), when in actuality they always get back the same class of
> object.
> >>
>
> That's a pretty fundamental misunderstanding of what classwide
> programming is all about. Yes, of course people can have all sorts of
> misconceptions, but this one is pretty basic, and not a misconception
> that could stay arround very long!
I'm with Robert on this one. You have to recognize something as an
idiom. When you see a function
function New_T return T'Class;
you just have to "know" that this is a constructor for T, and for T
only. Once you recognize the idiom, you know instantly that
type NT is new T with private;
...
O : NT := New_T;
is wrong, even though the compiler won't tell you it's wrong.
next prev parent reply other threads:[~1998-08-01 0:00 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-07-23 0:00 Help - Constructors - ASAP Maxim Senin
1998-07-26 0:00 ` Matthew Heaney
1998-07-27 0:00 ` dennison
1998-07-30 0:00 ` Robert I. Eachus
1998-07-30 0:00 ` tedennison
1998-07-31 0:00 ` Matthew Heaney
1998-07-31 0:00 ` Mats Weber
1998-07-31 0:00 ` Robert I. Eachus
1998-08-01 0:00 ` Matthew Heaney
1998-07-31 0:00 ` dennison
1998-08-01 0:00 ` Matthew Heaney
1998-08-01 0:00 ` Robert Dewar
1998-08-01 0:00 ` Matthew Heaney [this message]
1998-08-03 0:00 ` Mats Weber
1998-08-01 0:00 ` Robert Dewar
1998-08-01 0:00 ` Matthew Heaney
1998-08-03 0:00 ` Mats Weber
1998-08-03 0:00 ` Matthew Heaney
1998-08-03 0:00 ` Mats Weber
1998-08-04 0:00 ` Matthew Heaney
1998-08-04 0:00 ` Mats Weber
1998-08-05 0:00 ` Matthew Heaney
1998-08-10 0:00 ` Robert I. Eachus
1998-08-03 0:00 ` tedennison
-- strict thread matches above, loose matches on Subject: below --
1998-07-15 0:00 Maxim Senin
1998-07-16 0:00 ` Stephen Leake
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox