GC Magic

:- pragma foreign_decl("C", "
    void * luaMR_new(void *);
    void luaMR_free(void *);
    ").

:- pragma foreign_code("C", "

    MR_Word * luaMR_new(MR_Word word) {
        MR_Word * newptr = MR_GC_NEW_UNCOLLECTABLE(sizeof(MR_Word *));
        newptr = &word;
        return newptr;
    }

    void luaMR_free(void * ptr) {
        MR_GC_FREE(*ptr);
    }
").