[C++-sig] Re: Boost.Python : Byref parameters - no problems with static/non-static overloading

[Joel Gerard]

Thanks for the advice. There are a few things I'm still vague on though. I've been overloading
static, and non-static members without apparent problems, but I'm now starting to be suspicious. 

For instance, I have: 

Vector (Vector::*CreateCross1)(const Vector&) const  = &Vector::CreateCross ;
Vector (*CreateCross2)(const Vector&, const Vector&) = &Vector::CreateCross; 

.def("CreateCross",CreateCross1)
.def("CreateCross",CreateCross2)

The one I call as a bound method, and the other unbound, i.e.:

Vector2 = Vector1.CreateCross(Vector3)
Vector2 = module.Vector.CreateCross(Vector1,Vector3)

Is something going on here that I'm not seeing. They work ok apparently.

Regarding the vector problem. I cannot modify the original C++ code.  I want to keep Normalize as
an unbound method in Vector since I might have name collisions if I put them at the module level. 
I tried .def("Yahoo",Normalize3) but it too gave me a type error. What is Boost trying to do? The
function pointer is poiting to the correct function.  

Furthermore, don't you have to do something different than just a plain .def since the arguments
to Normalize are references? Does Boost automatically detect this?  How does it deal with
something like:

Add(int x, int y, int &result)

So when you do >>>Add(x,y,result) in python, what happens?

I think I'm missing something fundamental here... :(

Thanks for your help.
Joel

--- David Abrahams <> wrote: 
> "Mike Rovner" <> writes: 
> 
> > Joel Gerard wrote: 
> > 
> >> .def("Normalize",VectorNormalize1) 
> >> .def("Normalize",VectorNormalize2) 
> >> .def("Normalize",VectorNormalize3) 
> > 
> > You have to say .staticmethod("Normalize") 
> 
> Well, except he has a static method overloaded with 
> a non-static one, 
> and Boost.Python doesn't really support that idiom 
> (see thread at 
> http://aspn.activestate.com/ASPN/Mail/Message/C++-sig/1811696). 
> I 
> suggest forgoing instance-less access for the static 
> method as 
> follows: 
> 
> f32 nonstatic_Normalize(Vector&, Vector& kV) { 
> return Vector::Normalize(kV); } 
> 
> 
> .def("Normalize",VectorNormalize1) 
> .def("Normalize",nonstatic_Normalize) 
> .def("Normalize",VectorNormalize3) 
> 
> You can also def() the static normalize at module 
> scope: 
> 
> def("Normalize", VectorNormalize2); 
> 
> and then: 
> 
> >>> v = Vector() 
> >>> Normalize(v) 
> 
> which in many ways is a more natural interface 
> anyway. 
> 
> 
> HTH, 
> -- 
> Dave Abrahams 
> Boost Consulting 
> www.boost-consulting.com 
> 
> 
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