[Invoking a variadic C argument from OCaml]

>> Assuming a Linux system, you could lazily generate the glue code and
>> invoke dynamic linker on it. So the general case would be to call the
>> code generator.
> 
> On linux and x86, I could probably use an array where I would move by
> sizeof(some_type). I really want portability however (I want to use
> these bindings at least on windows too).

It might be worth investigating the "libffi" library.  If I guess
correctly, it lets you synthesize calls to native C functions when the
number and type of arguments are statically unknown.

- Xavier Leroy