Re: [boost] [fusion] Re: more help with unfused_typed (previously off-list)

From: Stjepan Rajko (stipe_at_[hidden])
Date: 2007-07-17 14:19:07

On 7/17/07, Stjepan Rajko <stipe_at_[hidden]> wrote:
> On 7/17/07, Tobias Schwinger <tschwinger_at_[hidden]> wrote:
> > Christian Holmquist wrote:
> > > My question is how to disable the call operators with fewer arguments
> > > than specified by Sequence, generated by unfused_typed<F, Sequence>.
> > > Before the switch to boost::result_of one could specialize the result
> > > struct to only handle the expected Sequence type, thus disabling
> > > unwanted operators. I'm not familiar with boost::result_of to describe
> > > this however.
> >
> > ... I removed that kind of control over the overload sets of the Fusion
> > functional adapters (you can't pass emptiness through result_of), but
> > I'm not really happy about it.
>
> Hmm... now that I think of it, I guess in something I was working on I
> implemented a "has_result_of" trait that checks for either existence
> of result_type, or the right result overload... that might also work
> here, but I'm not sure how my has_result_of implementation fares, and
> whether it can be fixed to use result_of directly (i tried and failed
> for some reason) and also work when result_of is a typeof forwarder.
> So I don't know about whether this might also be an avenue.
>

... I guess I called it "result_of_defined" - the code is at
http://tinyurl.com/23xz6t if you have any feedback.

Stjepan