[boost] Feature request: exception filter for Boost.Bind

7 Oct 2005

      Hello, world!

Today I was browsing RSDN (Russian Software Developer Network) forums 
and found a great trick for exception handling 
(http://rsdn.ru/Forum/Message.aspx?mid=1420259&only=1):
==============
void TheFunction()
{
     try {
         ...
     } catch(...) {
         ExceptionFilter();
     }
}

void ExceptionFilter()
{
     try {
         throw;
     } catch(Exception1 const& e) {
         //Blah-blah 1
     } catch(Exception2 const& e) {
         //Blah-blah 2
     } catch(Exception3 const& e) {
         //Blah-blah 3
     } catch(Exception4 const& e) {
         //Blah-blah 4
     } catch(Exception5 const& e) {
         throw; //Just rethrow
     } catch(...) {
         //Something other
     }
}
==============

It turns out that this trick is explicitly permitted by the Standard (as 
it was pointed in this post: 
http://rsdn.ru/Forum/Message.aspx?mid=1420469&only=1).

I think this trick can be really helpful in conjunction with Boost.Bind.

It would be great to write something like this:
====================
boost::function<void()> func= 
boost::bind_with_filter(&SomeObj::func1,obj,logging_filter());
====================
If SomeObj::func1 throws an exception then logging_filter will write it 
into the application's log and suppress its further propagation.

Or another use-case:
====================
boost::function<void()> 
func=boost::bind_with_filter(&ComObject1::func,obj,com_error_translator());
====================
com_error_translator will translate exceptions from Microsoft's 
_com_error to something like std::runtime_error.

--
With respect,
		Alex Besogonov(cyberax@elewise.com)