Is it possible to use "out" parameters with MacRuby, such as NSError? In my particular case I'd like to capture errors that result from parsing XML with NSXMLDocument using the initWithData:options:error: method. I tried (naively) just instantiating an NSError instance and handing it to that method, but ended up with this: irb(main):037:0> e = NSError.new => #<NSError:0x80067cc40> irb(main):038:0> doc = NSXMLDocument.alloc.initWithData(data, options:NSXMLDocumentValidate, error:e) ArgumentError: can't convert Ruby object `#<NSError:0x80067cc40>' to Objective-C value of type `^@' from (irb):38:in `initWithData:options:error:' from (irb):38 from /usr/local/bin/macirb:12:in `<main>' Any help or insight is appreciated. Cheers, Alex ---- Musings & Notes — http://alexvollmer.com Track what you lend and borrow — http://moochbot.com