Re: [boost] Re: first sight

From: David Abrahams (david.abrahams_at_[hidden])
Date: 2002-01-14 18:15:48

----- Original Message -----
From: "bill_kempf" <williamkempf_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Monday, January 14, 2002 5:56 PM
Subject: [boost] Re: first sight

> --- In boost_at_y..., "David Abrahams" <david.abrahams_at_r...> wrote:
> >
> > ----- Original Message -----
> > From: "bill_kempf" <williamkempf_at_h...>
> > > > You mean, "may catch(...) and fail to rethrow?"
> > >
> > > Mostly, yes, though a catch(...) and some operation that assumes
> > > an "error" occurred could also be considered a bug in this case.
> In
> > > general I'd consider such catch blocks, especially in library
> code,
> > > to be a bad idea in any event.
> >
> > Especially in library code. Applications often need to do this as a
> safety
> > net in order to deal with and report unanticipated errors.
>
> And it's a simple violation of the contract if they do this in a MT
> application using our library, which is something I can live with as
> the library "vendor".

When I say "applications" I'm basically talking about the "main" thread, in
main() or some equivalent top-level function. Would that still be a
violation?

If so, there's a way out, but you have to let people catch our exceptions
explicitly

catch(thread_cancellation const& e) {throw;}
catch(...)

> That mindset tends to prevent people from thinking effectively about
> > exception-safety. In fact, the issues are mostly the same as they
> were for
> > your more "traditional" error-handling schemes, at least if you
> exclude the
> > scheme where errors are ignored. If you'd like to discuss
> the /science/ of
> > exception-safety I'll be happy to help you to arrive at a more
> productive
> > relationship with exceptions ;^) ;^)
>
> I don't think it's that disempowering, at least in my case.  It just
> means I treat things more carefully when exceptions directly effect
> the design.  Most of the FUD involved in this for me comes from the
> fact that there are still "dark corners" in the "art" that I'm not
> versed in.  So any help you can provide would be well
> appreciated ;).

To which "dark corners" are you referring? We can start there.

>  Have you considered writing a book on this
> subject? :)

Yes, I had serious plans to do it, and interest from AW, but:

1. The appearance of Herb's book was a major discouragement. In particular,
the title seemed to claim the domain.

2. Whenever I think about it, I think "there's really not that much to say".
I know that's not really true; I have loads of posts to c.l.c++.m which I
could distill, but I seem to have a much easier time saying "no, no, don't
go that way, the truth is over here!", than whatever is required for a book.

3. I've barely got time to do the stuff I can get paid real money for ;-)

If my current gig works out for me, though, maybe I'll take some time to
write the book later this year.

-Dave