2008/7/1 Emil Dotchevski <emil@revergestudios.com>:
On Tue, Jul 1, 2008 at 1:53 PM, Daniel James <daniel_james@fmail.co.uk> wrote:
Exceptions seem to work in g++ with RTTI disabled.
Catch needs to discriminate between different exception types in a way similar to dynamic_cast, except that unlike dynamic_cast, it needs to work for objects of non-polymorphic types as well. That's what I was referring to.
Sorry if my email wasn't very clear. I was just pointing out that exceptions work with the -fno-rtti compile option, which is what BOOST_NO_TYPEID supports. So disabling exceptions when it's defined might be the wrong thing to do. The situation might be different for other compilers. You'll know better than me.
I think the best option is to #define BOOST_EXCEPTION_DISABLE if BOOST_NO_TYPEID is defined.
This seems very disruptive. If that's the only solution then, at this stage in the release cycle, it might be better to just leave things as they are and live with the regression (it's for an undocumented feature, so I don't think it's a show stopper).
It seems pretty straight forward to me
But doesn't it change the behaviour of any library which uses your library? That's why I said it seems disruptive.
my only question was what's the right way to do this since I don't know much about configuring Boost.
Well, I'm no expert on this. I agree that if you've disabled exceptions, you probably should define BOOST_DISABLE_EXCEPTIONS. If someone uses it badly (checking for it in a header without first including your headers) it could cause an ODR violation, but that's a minor concern. You could possibly have two separate macros - one user settable one which tells Boost.Exception to disable exceptions, and one which Boost.Exception sets when exceptions are disabled or aren't available. But that's probably too complicated, no one would ever know which one to use. Also, looking at Boost.Config, there are user settable options to which BOOST_DISABLE_EXCEPTIONS could be added (since it's fairly universal): http://www.boost.org/doc/libs/1_35_0/libs/config/doc/html/index.html#boost_c... Daniel