Re: [boost] [exception][policy]

From: vicente.botet (vicente.botet_at_[hidden])
Date: 2008-09-01 02:33:23

----- Original Message ----- 
From: "Emil Dotchevski" <emil_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Sunday, August 31, 2008 8:59 PM
Subject: Re: [boost] [exception][policy]

>
> On Sun, Aug 31, 2008 at 8:54 AM, vicente.botet <vicente.botet_at_[hidden]> 
> wrote:
>>> On Sat, Aug 30, 2008 at 7:21 PM, vicente.botet 
>>> <vicente.botet_at_[hidden]>
>>> wrote:
>>>>>
>>>>> What use case do you have in mind?
>>>>
>>>> Sorry, but I dont understand your question. What use case do I have in
>>>> mind
>>>> for what? Maybe you can question is related to:"What is worst is that 
>>>> the
>>>> final user can not do anything for the exceptions thrown by 3pp 
>>>> libraries
>>>> that do not use boost::enable_current_exception or
>>>> boost::throw_exception."
>>>
>>> I am trying to be as objective as possible in answering your previous
>>> questions. For that, I need to understand what is the use case you
>>> have in mind. I understand that it involves a 3rd party library
>>> throwing an exception, but more details please:
>>
>> My own application request a thread pool library to execute a function F
>> asynchronously
>>
>>> - who catches the exception initially?
>>
>> A thread pool  (packaged_task) library, which calls the function F 
>> calling a
>> 3pp function 3ppF throwing an exception (3pp_exception1 or 
>> 3pp_exception2)
>>
>>> - who copies it into an exception_ptr?
>>
>> the same thread pool (packaged_task) library calls the current_exception 
>> and
>> stores the exception_ptr in the future associates to the packaged task.
>>
>>> - who rethrows it?
>>
>> The thread pool (packaged_task) Library which rethrow the stored 
>> exception
>> when the user wait on the future value.
>>
>>> - who catches it after the rethrow?
>>
>> My own application, which requested a thread pool library to execute the
>> function F
>>
>> Emil, while answering your question I see that I was wrong when I said 
>> that
>> "final user can not do anything for the exceptions thrown by 3pp 
>> libraries":
>> The final user can define a function Ftry_catch wich wraps the call to 
>> the
>> function F by a try-catch, use the boost:throw_exception to throw each 
>> one
>> of the exceptions 3ppF can throw, and request the thread pool library to
>> execute the function Ftry_catch instead. Was this what you mean?
>
> I didn't mean anything in particular, I just wanted to understand the
> problem you are trying to solve. :)
>
> 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.

Can my original idea of exception registry be implemented by the 
Boost.Exception library?

Vicente