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Date: Mon, 31 Oct 1994 12:52:52 +0800
From: rtm@island.com (Richard Minner)
Message-Id: <9410312052.AA01593@kismet.>
To: tiff@sgi.sgi.com
Subject: Re: C++ tiff library
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John M Davison <davisonj@ecn.purdue.edu> writes:

>         I would advise against any major attempt at C++-izing libtiff until at
> least 1996 or 1997.  The C++ standard is slated to come out in mid-1996, and it
> is unlikely that any vendors will have stable C++ compilers out before early
> 1997.

Depending on your definition of "major" I can agree or disagree.  As I
reported before, a relatively simple C++ification tool about a week and
is working swell.  I agree that C++ is not quite ready for the masses, but
very nice implementations are available at least on the two platforms I
care about most for my work, and I expect others are in similar positions.
I don't doubt that the demand for a libtiff++ will be quite a bit smaller
than the demand for "C libtiff" for some time, but the libtiff++ demand
may be large enough to warrant some sort of joint effort.  As I mentioned
before, if there is sufficient interest perhaps the ++ gang (all three of
us :-) should break off a new list.  We'll see.

You probably won't be surprised that my view of the state of C++ is more
optimistic than yours, since we have adopted C++ as our Language of Choice.
You are correct that some important new features are not yet available
at all, and that availability of other features varies by vendor.  I
neglected to state clearly that the "stable subset" is not just a subset
of the language itself but of platforms and implementations.  This does
make the question of "what is portable C++" quite messy.  The picture
has a shape something like this:


			features
		  a b c d e f g h i j k
	p	1 x x x x x   x x x   x
	l	2 x x x x x x x   x x
	a	3 x x x x x x x x
	t	4 x x x x x x 
	f	5 x x x x 
	o	6 x x x
	r	7 x x x
	m	8 x x x
	s	9 x x

That is, the more features you want, the fewer platforms you have to
choose from, and vice versa.  For my project we have chosen to limit
platforms in favor of a better feature set.  Others may not be able to
make that tradeoff.  You may be right that it would be too difficult
to reach consensus on what C++ subset to use for a shared libtiff++.

However, if one has faith that C++ will arrive in full one of these days,
it can be quite sensible to get going with it now, even lacking things
like namespaces and RTTI.  (It's not a huge library.)

Anyway, thanks for the counter arguments, well said.
--
Richard Minner  rtm@island.com
Island Graphics Corporation
Sacramento, California

