From: gga <GGarramuno@...>
Date: 2005-02-18T05:54:52+09:00
Subject: Re: SWIG: ruby proc->c function pointer

I finally got around to trying this.  Thanks.
Unfortunately, the latest SWIG (v1.3.22) seems to choke on it, with:

irb(main):005:0> Callback.invoke(Proc.new{|str| p str}, "abc")
TypeError: cannot convert nil into String
        from (irb):5:in `invoke'
        from (irb):5

Looking at the code, SWIG fails in the StringValuePtr() conversion
here.

/* Get type mangle from class name */
SWIGRUNTIME(char *)
SWIG_Ruby_MangleStr(VALUE obj)
{
  VALUE stype = rb_iv_get(obj, "__swigtype__");
  return StringValuePtr(stype);
}