On Monday 12 October 2009 08:47:22 troy d. straszheim wrote:
> >> boost::function<int(X*, int)> bf0(fobj);
> >
> >
> > Why do you need to use boost::function here? Shouldn't the type be
> > deduced automatically?
> >
>
> Note that the .def() of the various boost::function objects work without
> requiring the user to specialize get_signature, (since this modified
> get_signature metafunction knows about boost::function objects).
[snip]
> I think interoperability with boost::function is a Good Thing, but in
> the example above (and the previous), all it does is give def() a way to
> tell what the signature of the function object is at compile time, and
> it does so at a runtime cost.
At least for my case, that extra virtual function call is a killer.
> A specialization of get_signature works,
> but strikes me as kinda ugly (it should at least be moved out of
> 'detail' if it is a user customization point). How about something like
>
> class_<T>("T")
> .def("f1", f1, sig<void(T*, double)>)
> .def<void(T*, double)>("fi", f1)
I'd rather have something along the lines of
.def< mpl::vector<void,T*,double> >("f1",f1)
by using function_types to compose the currect function signature.
Alternatively, one could have the sig<> template above be a def_visitor and
take the appropriate template arguments without the need to modify class_::def
at all.
> >> I'm fairly new to the internals of boost.python, and only just now got
> >> this working... Do you see problems with this, specifically the
> >> conversion of get_signature from function to metafunction?
> >
> >
> > I don't see any problems with the conversion of get_signature to a
> > metafunction. Do compile times get any longer?
>
> I haven't checked this yet. I have other concerns re typechecking and
> automatic conversions...
Care to elaborate?
Regards,
Ravi
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