Re: [boost] Review Request: Boost Exception

From: Emil Dotchevski (emildotchevski_at_[hidden])
Date: 2006-11-14 21:06:03

David Abrahams wrote:
> Matthew Herrmann <matthew.herrmann_at_[hidden]> writes:
>
>> I think Mr Abrahams is referring to an idea similar to this: (please
>> ignore the class name, it is a placeholder only)
>>
>> void read_file()
>> {
>>    boost::exception_info e(..., filename, current_pos, is_connected);
>>     ...
>>     e.success();
>>     return;
>> }
>>
>> e.success() sets a flag to true, which prevents the generation of
>> error information when the object is destroyed.
>
> No, that's not quite what I meant.
>
> void tag_exception(boost::exception& x)
> {
>    // do something to x
> }
>
> void read_file()
> {
>   boost::adorn_exception e( boost::bind( tag_exception, _1 ) );
>   ...
> }

Could you provide more detail on the "do something to x" part? It seems to 
me that it would require something similar to the boost::exception::pimpl 
class, in that it must be able to store arbitrary values, but unlike 
boost::exception::pimpl it would have to keep some kind of proxy for each 
stored object, to be evaluated later if something throws.

Wouldn't that amount to executing a lot of code and using a lot of storage, 
even if nothing throws?