> ... I've now tried cvs version of SWIG which splits c++ constructors into two methods,
> - singleton method 'alloc' 
> - and instance method 'initialize'
> 

Just to be clear for anyone else following this thread; the Ruby method 
names are still Foo.new and Foo#initialize. I am aware of the changes 
for the Ruby allocation framework in 1.7 and am trying to decide exactly 
what impact (if any) it should have on SWIG's code generation. It does 
seem to be the case that Matz has made the new allocation framework 
back-compatible, i.e. SWIG-generated code that provides Foo.new instead 
of Foo.allocate seems to do the right thing.