Re: [boost] [boost exception]complaint

From: Peter Bartlett (pete_at_[hidden])
Date: 2008-08-20 13:10:16

Quoting Robert Ramey <ramey_at_[hidden]>:

>>> I have no idea what else this might break.
>>
>> It will break people using throw_exception but throwing things not
>> derived from std::exception. This was an implicit requirement anyway,
>
> What is an "implicit requirement"?  You mean that previous users
> of boost/throw_exception where remiss if they didn't derive
> from std::exception or if they didn't surround throw_exception
> with #if BOOST_NO_TYPEID.  I like to think I'm a smart guy
> but I don't claim to be telepathic.

Why would you need to surround throw_exception with #if BOOST_NO_TYPEID?
The template function works whether it is defined or not...

>> but users will have previously got away with it if they never actually
>> exercised their code on a no-exceptions platform.
>
> Hmmm - It looks to me that the previous code would work fine
> on a no-exeptions platform - all it did was call a user defined
> throw_exception function.

At the very least the fact that the declaration for that case in  
boost/throw_exception was throw_exception( std::exception ) was at  
least a hint that it was intended for use with classes deriving from  
std::exception.

Admittedly the client could crack open the boost namespace and add  
another overload for their own exception type(s), and include that  
before boost/throw_exception.hpp. Perhaps this use case was not  
sufficiently thought about in prior discussions. For me though the  
benefits of enabling Boost.Exception functionality for all existing  
code that uses boost::throw_exception outweighs that cost.