Re: [boost] [inspect] exceptions (FW: [Boost-users] no exceptions)

Subject: Re: [boost] [inspect] exceptions (FW: [Boost-users] no exceptions)
From: Vicente BOTET (vicente.botet_at_[hidden])
Date: 2011-03-23 20:51:33

> Message du 23/03/11 22:13
> De : "Joaquin M Lopez Munoz" 
> A : boost_at_[hidden]
> Copie à : 
> Objet : Re: [boost] [inspect] exceptions (FW: [Boost-users] no exceptions)
> 
> Vicente BOTET  wanadoo.fr> writes:
> 
> > 
> > > On Tue, Mar 22, 2011 at 12:16 PM, Krzysztof Czainski
> > > <1czajnik  gmail.com> wrote:
> > > > What about boost/detail/no_exceptions_support.hpp?
> > [...]
> >
> > I'm wonderyn if the following wouldn't be more natural
> > 
> > void foo() {
> > BOOST_TRY {
> > ...
> > } BOOST_CATCH(const std::bad_alloc&) {
> > ...
> > BOOST_RETHROW
> > } BOOST_CATCH(const std::exception& e) {
> > ...
> > } BOOST_CATCH_ALL {
> > ...
> > }
> > }
> 
> If you refer to why BOOST_CATCH_END is needed in the original
> formulation, consider the following:
> 
> if(so)
> BOOST_TRY{
> foo();
> }
> BOOST_CATCH(const std::exception& e){
> bar();
> BOOST_RETHROW
> }
> else
> baz();
> 
> This, using your variation, expands to
> 
> if(so)
> if (true){
> foo();
> }
> else if (false){
> bar();
> }
> else
> baz();
> 
> which is equivalent to (note the braces)
> 
> if(so){
> if (true){
> foo();
> }
> else if (false){
> bar();
> }
> else{
> baz();
> }
> }
> 
> which is clearly not the intention.

Yes I see. This is why I added BOOST_CAT_ALL, but the its use can not be forced and as your example shows can have dramatic effects.

Thanks,
Vicente