From: Dennis Newbold <dennisn@...>
Date: 2002-03-29T09:19:16+09:00
Subject: Re: Ruby SWIG problems

Hi James,

     One final thought.  I'm a little confused as to why you would
want to wrap a C++ class, when Ruby already supports classes. Wouldn't
it make more sense to declare the class in Ruby, and have each Ruby
method do its work by calling a regular C routine?  In addition, Ruby
may not be able to properly connect to your C++ code due to name-mangling.
And, if you can figure out how to properly match the name mangling method
used by a given compiler, then you'll have problems porting it to a
different C++ compiler which may use a different nmae mangling scheme.
It seems like too much work for too little payback, if you ask me.
Course, thats just my take, and I don't know the "big picture" as you do.
Take care.

Dennis

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|     The way to be happy is to be good     |
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On Thu, 28 Mar 2002, James Adam wrote:

> Hi
> 
> I've been trying to use Ruby SWIG, but been having limited success.
> Currently I'm using SWIG 1.3.11, and Ruby 1.7.2 ('stable' ruby versions have
> given me even less success than below). Here's the scoop:
> 
> i've got 3 files:
> 
> /* File : example.h -------------------*/
> 
> class TestClass {
> public:
>   TestClass();
>   int result;
> 
>   int add(int x, int y);
> };
> 
> /* File : example.cxx ------------------*/
> 
> #include "example.h"
> 
> TestClass::TestClass() {
>  result = 0;
> }
> 
> int TestClass::add(int x, int y) {
>  result = x + y;
>  return result;
> };
> 
> /* File : example.i ----------------------*/
> %module example
> %include example.h
> 
> /*---------------------------------------*/
> 
> ....and i run the following commands, all via cygwin (Ruby & SWIG both also
> compiled using cygwin):
> 
> $ swig -c++ -ruby example.i
> $ gcc -c example.cxx
> $ gcc -c example_wrap.cxx -I/usr/local/lib/ruby/1.6/i386-cygwin
> $ gcc -shared example.o example_wrap.o -o example.so -lcygwin-ruby17
> 
> .... all with no errors. Now when i try and use my new module 'example' - i
> get this:
> 
> $ irb
> TypeError: wrong argument type Fixnum (expected Class)
>         from (irb):1:in `require'
>         from (irb):1
> irb(main):002:0>
> 
> Anyone have any ideas? I've tried using different class definitions, etc etc
> but with no joy.
> 
> Thanks
> 
> James
> 
> 
>