Re: [boost] [exception][policy]

From: vicente.botet (vicente.botet_at_[hidden])
Date: 2008-09-01 17:34:12

----- Original Message ----- 
From: "Emil Dotchevski" <emil_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Monday, September 01, 2008 9:51 PM
Subject: Re: [boost] [exception][policy]

> On Sun, Aug 31, 2008 at 11:33 PM, vicente.botet
> <vicente.botet_at_[hidden]> wrote:
>> Can my original idea of exception registry be implemented by the
>> Boost.Exception library?
>
> What are the benefits of the "exception registry" over the "function
> wrapper" approach that you mentioned?

Maybe my initial "exception registry" proposal has some drawbacks and need 
to be pollished. The benefits I see are:
* The exception_registry will be done once for all and will profit to every 
user of the exception_ptr library, while the wrapping approach forces every 
user to wrap its functions.
* The wrapping approach has one try-catch block more than the 
exception_registry approach, so less performant.
* The exception_registry approach centralize the knowledge of which 
compilers provides the mechanisms to ensure that current_exception works for 
any exception on the Boost.Exception library. The wrapping approach on the 
best case split this knowledge into two libraries, and if the try_catch 
functor class do not exists, into each user of the current_exception 
function direct or indirect.

Do you see any benefits of the "function wrapper"  over the "exception 
registry" approach?  Please, let me know if you have a use case where the 
exception_registry proposal do not work? I'm really interested in seen if 
together we can get a better solution.

> Do you have a use case where the
> "function wrapper" wouldn't work, but the "exception registry" would?

No, not now. I was asking this only because I think that it is a better 
solution to include it in the Exception library and also because you were 
proposing this for the thread_pool library. Quotting you from your preceding 
post : "Your function wrapper solution is a possibility. Another possibility 
is, if the thread pool library is not third party, it can implement your 
original idea of exception registry." So, if you think that this could be a 
possibility for the thread_pool library, it should be even better for the 
exception library, because in this way, other libraries will profit of this 
commonality, isn't it?

Best,

Vicente