From: Ben Giddings <bg-rubytalk@...>
Date: 2005-02-05T05:48:30+09:00
Subject: Re: Ruby/DL and functions that modify a pointer

Takaaki Tateishi wrote:
>> Do you know the answer to the other question?  How to wrap a function 
>> that modifies a structure you pass in?
> 
> 
> Just use 'extern' as follows:
> 
> module MyLIB
>   extend Importable
>   dlload "...."
>   MyStruct = struct [
>     "int foo[3]",
>   ]
>   extern "int get_data(void*)"
> end
> 
> ptr = MyLIB::MyStruct.malloc()
> MyLIB.get_data(ptr)


Thanks so much Takaaki, that works perfectly, I'm now wrapping a library 
and doing some pretty impressive things, all in less than 100 lines of 
Ruby code!

Ben