Hi Rubyists,

I'm working on wrapping a C library, and I've got a couple of things I
can't quite figure out how to manage:

1) Wrapping functions that take variable-length arguments (varargs). Is 
   there are standard way to do this? The best I've found is libffi,
   which lets you construct the stack frames you need to do this, but it
   seems like this would be a problem someone would have solved a while
   ago.

2) Wrapping structures with flexible arrays. How do I realloc the
   structure held by a VALUE? Or do I have to create an entirely new
   Ruby object each time I need to resize the structure?

Thanks,

-Jon