question about the OCaml/C interface

[Jean-Marc EBER <jeanmarc.eber@lexifi.com>]

Hello to all,

I have a little technical question about the OCaml/C interface:

Is the following code "correct":

CAMLprim value my_func(...)
{
   CAMLlocal2(ret);
   ...
   result = ...
   ret = caml_alloc(5, 0);
   Store_field(ret, 0, caml_copy_double(result));
   ...
   CAMLreturn (ret);
}

or, arguing that [caml_copy_double] allocates and may therfore launch a gc cycle 
that may therefore modify [ret], one must write:

CAMLprim value my_func(...)
{
   ...
   CAMLlocal2(v, ret);
   ...
   result = ...
   ret = caml_alloc(5, 0);
   v = caml_copy_double(result);
   Store_field(ret, 0, v);
   ...
   CAMLreturn (ret);
}

I don't find a clear answer to that question in the documentation.

Jean-Marc Eber