jameskilton / rbplusplus

This is an issue with rbgccxml.

The short:

t.update(f)

is what's going to work.

There's a problem with your example though. Test::update makes a lot of assumptions about the parameter passed in, but at first glance, and what GCC-XML gives me, Test::update takes a pointer to a single foo instance, not an array. Unfortunately, C/C++ decided to make arrays and pointers act the same, which makes this situation very difficult to reconcile.

There's another smaller issue, how does Test::update know how many elements are in the array? Do you expect a NULL at the end?

I'd recommend going with a std::vector, but Rice doesn't have the best support for collections like this yet.

I really don't know the best way of dealing with this situation right now. I would recommend starting with 1) changing that to a std::vector and 2) building a from_ruby method:

template<>
std::vector<foo> from_ruby< std::vector<foo> >(Rice::Object obj) {
  Rice::Array arr(obj);
  std::vector<foo> vec;

  // ... do processing

  return vec;
}

In rb++, you'll need to put this in a custom code file. See http://github.com/jameskilton/ogrerb/tree/master/wrappers/noise/ for an example on how to do this.

Alrighty, thanks for the response and for the suggestions. I'll look into creating the from_ruby method.

-- Thanks again!
Bryan

Hi again... so from your example code, I see how I should use from_ruby to do conversions into C++ code. However, I'm not quite understanding where/how to use the specialized from_ruby templates. Do they get used automatically or do I have to specify its use in some of the code generated by rb++? Is there a file naming convention for the custom templates such that they can be used automatically? I looked at your ogrerb code to see how you were actually using the custom templates you pointed me to and I didn't see anything obvious.

-- Thanks!
Bryan

The key is Extension#sources and the :include_source_dir option. What you see in the noise wrapper is the code/ directory with some source files. If you open up build_noise.rb, you'll see the :include_source_dir directive pointing to this directory.

What happens here is this directive is telling Rb++ to copy all source files (h hpp c cpp) into the working directory for compilation. At the same time, any header files found are then included into all generated source files.

Thus, with this mechanic, you can add your own code to the compiled extension.

As for naming convention, as long as the methods are Rice::to_ruby and Rice::from_ruby, they'll be picked up just fine (due to the type specification).