Re: [Caml-list] Val_int vs caml_copy_nativeint

[Romain Beauxis <romain.beauxis@gmail.com>]

2011/8/7 Erik de Castro Lopo <mle+ocaml@mega-nerd.com>:
> Hi all,

Hi,

> I'm writing a C stub function to allow the calling of a C library
> function from ocaml. The return from the stub is a tuple and I'm
> doing this:
>
>    /* Package up the result as a tuple. */
>    v_response = caml_alloc_tuple (3) ;
>
>    Store_field (v_response, 0, Val_int (width)) ;
>    Store_field (v_response, 1, Val_int (height)) ;
>    Store_field (v_response, 2, caml_copy_string (code)) ;
>
>    CAMLreturn (v_response) ;
>
> The above works now, but didn't work when I was using
> caml_copy_nativeint() instead of Val_int() and I'd like to know
> why. I found it especially confusing because caml_copy_string()
> worked and was obvioulsy the right thing to do.

Reading very briefly the headers. is seems to me that intnat = value =
long. Could it be that on the arch you're using sizeof(int) <
sizeof(long) ?

Romain