Fiddle::Pointer#free

static VALUE
rb_fiddle_ptr_free_get(VALUE self)
{
    struct ptr_data *pdata;
    VALUE address;
    VALUE arg_types;
    VALUE ret_type;

    TypedData_Get_Struct(self, struct ptr_data, &fiddle_ptr_data_type, pdata);

    if (!pdata->free)
        return Qnil;

    address = PTR2NUM(pdata->free);
    ret_type = INT2NUM(TYPE_VOID);
    arg_types = rb_ary_new();
    rb_ary_push(arg_types, INT2NUM(TYPE_VOIDP));

    return rb_fiddle_new_function(address, arg_types, ret_type);
}