The function defined by the IDL operation returns multiple values. The first value returned is that value corresponding to the declared return value, unless the declared return value is void. Following the value corresponding to the declared return value, if any, the succeeding returned values correspond to the parameters that were declaredout andinout, in the order in which those parameters were declared in the IDL declaration.
Note that this implies that generated functions corresponding to operations declared void, which have neitherout norinout formal parameters, return zero values.