initialize_copy

static VALUE
BigDecimal_initialize_copy(VALUE self, VALUE other)
{
    Real *pv = rb_check_typeddata(self, &BigDecimal_data_type);
    Real *x = rb_check_typeddata(other, &BigDecimal_data_type);

    if (self != other) {
        DATA_PTR(self) = VpCopy(pv, x);
    }
    return self;
}