Gentlemen, I just want to start by saying thanks for the comments. I'm wrapping my brain around some of it, and hopefully I'll have time to work on this again very soon. On 8/8/06, Alexander Nasonov <alnsn@yandex.ru> wrote:
So, this library should a simple utility library that doesn't rethow if possible and doesn't hide a lot from a user.
I will do some research into using preprocessor metaprogramming to remove the rethrow, or at least provide a macro that does that. 1. Catch a list of exceptions in one line:
try { throw std::logic_error("testing"); } BOOST_CATCH_PP_SEQ((ex1)(ex2)(ex3), my_exception_handler());
There is no need for MPL counterpart because you can always transform PP sequence into MPL sequence (but this functionaly seems to be missing in boost). If you can't do that (e.g. you need to mpl::push_back, or apply mpl::transform_view), then this library goes beyond a simple utility ;-)
2. Catch and dispatch (or visit, if you like)
try { throw std::logic_error("testing"); } BOOST_CATCH_AND_DISPATCH(std::exception&, my_exception_handler());
This code rethows but it doesn't catch(...) but rather catch(std::exception&).
Needless to say that my_exception_handler should be as simple as possible. Macros inside this class should be avoided because it's often impossible to go to a definition of a function inside it.
Currently, my_exception_handler in item 1 has different (and much simpler) interface compared to that from item 2. It would be nice to have common interface.
I personally think that item 2 has the easier interface. I will definitely work on a macro where you can specify what to catch, in lieu of always catching ... . Furthermore, I really like using the MPL sequence, because I found that it is very easy to order the exceptions so that you don't accidentally have catch(std::exception&) before you catch a derived exception, such as std::logic_error. Jeremy