void
DESTROY(obj)
    SV * obj
    INIT:
        struct my_struct * wrap;
        SV * holder;
        IV val;
        void * wrap;

        if(!SvROK(obj)) croak("Expected reference to object");
        holder = SvRV(obj);
        if(SvTYPE(holder) != SVt_PVMG)
             croak("The object type is wrong");
        val = SvIV(holder);
        wrap = INT2PTR(struct my_struct *, val);

    CODE:
        Safefree(wrap);