I've been digging a little further, and it seems that the rbffi_Function_ForProc
function defined in Function.c does exactly what I want, since I have a
FFI::FunctionType (i.e., self::Callback), and a Proc (the value argument of
#to_native), and I would like to turn this into a FFI::Function.

Would it be possible to expose this function to Ruby?

On 22/09/13 13:05, Matijs van Zuijlen wrote:

> Hello,
> 
> I'm trying to create a DataConverter that represents a callback function. The
> code basically boils down to this:
> 
> module Lib
>   include FFI::Library
>   ffi_lib 'some-library'
> end
> 
> class Foo < Proc
>   extend FFI::DataConverter
> 
>   Callback = Lib.callback ... # usual call to FFI::Library.callback
> 
>   def self.native_type
>     self::Callback
>   end
> end
> 
> [The reason I'm doing this is that I want to wrap procs passed from ruby in some
> argument conversion code using a method defined on, in this case, Foo]
> 
> Now, I'm unable to figure out what the definition of Foo.to_native should be.
> Foo::Callback is of type FFI::FunctionType, which doesn't have a to_native method.
> 
> Any ideas?
> 
> Thanks and regards,
> 

-- 
Matijs