Re: [boost] [statechart] - templated states do not compile (transit not defined)

From: Andreas Huber (ahd6974-spamgroupstrap_at_[hidden])
Date: 2006-03-09 18:02:14

David Greene wrote:
> Oliver.Kowalke_at_[hidden] wrote:
>> Hello,
>> the code below doesn't compile (gcc-3.4.6 on Linux).
>> 'transit in scope not defined'
>> Any glue?
>> Regards,
>> Oliver
>
>> { return transit< Z< S > >(); } <<=== error
>
> Try { return this->template transit< Z< S > >(); }
>
> Can anyone comment on whay this is necessary?  Is it standard
> behavior or a gcc limitation?

It's standard behavior, dependent name lookup in templates. I faintly 
remember an article that explained the problem really nicely but can't 
find it right now. In a nutshell, when going through the template the 
compiler cannot know whether transit< Z< S > >() is a call to a member 
function of the base class or a call to a ctor of a class template. 
IIRC, this is because of possible template specializations of the base 
class.

>  gcc 4 has the same issue.  If
> it is standard behavior, then the statechart docs need to be
> updated to reflect that because right now they don't include
> the "this->template " part.

You mean an example doesn't use that syntax? I'd be grateful for a 
pointer.

Thanks & Regards,

-- 
Andreas Huber
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