[plt-scheme] FFI Problem

Jon Rafkind wrote:

> (_ptr o <type>) will generate an object for you on the fly during the 
> call to the C library so you dont need to supply a variable to the 
> function call. You do need to give an output lambda to _fun which will 
> return all the output variables:

You made me lookup _prt again. It seems I need (_ptr i <type>) 
everywhere I wrote (_ptr o <type>).

Thanks,
Jens Axel Søgaard