Re: Diagnostic improvements in 1.78/1.79

From: Gavin Lambert (boost_at_[hidden])
Date: 2022-02-15 02:20:12

On 15/02/2022 14:53, Peter Dimov wrote:
>> What's probably a more practical solution might be to have potential throw
>> sites declare a context object on their stack.  Any Boost-aware throw that
>> occurs while these objects are on the stack would capture whatever additional
>> information is requested by the context objects that are still in scope at the
>> time.  This might be a stack trace, a source location, a plain string, or any other
>> context info (e.g. method parameters) that seems useful.
> 
> I think I like Emil's user-provided handler better, because with it the user would
> control whether and what is collected.

I did consider mentioning that, but what I don't like about that option 
is that it leaves things a bit too vague.

(And in terms of ThrowException itself, it's fundamentally equivalent to 
the NO_EXCEPTIONS path, by making it call a user-provided method to do 
the actual work.  Which then seems to defeat the point of having it be a 
library at all.)

It puts the burden entirely on the end-user to select the mechanism for 
error info propagation, and library authors would have a harder time 
interfacing with it.