On Nov 12, 2007, at 8:15 AM, K. R. wrote:

> hi @all
>
> I would like to extend my rubyapp with a c++ program. I used the
> features of mkmf (require 'mkmf') and saved it into the extconf.rb. So
> already the whole program is running, but I want to compile the c-file
> with g++ instead of gcc compiler.
>
> How can I change this options?

I had a similar problem and came up with this ugly hack (hopefully  
there's a more official way to do this) which works at least under  
MacOS X and FreeBSD:

# XXX hack to get C++ standard library properly linked into shared  
object
# $libs = append_library($libs, "supc++")  # doesn't work
if Config::CONFIG["arch"] =~ /-darwin\d/
   CONFIG['LDSHARED']="g++ -dynamic -bundle -undefined suppress - 
flat_namespace"
else
   CONFIG['LDSHARED'] = "g++ -shared"
end

  --Young