You can't have constant voltage and constant current at the same time unless you have a constant load. You either adjust the voltage to keep the current constant, or you adjust the current to keep the voltage constant.
If you have a constant load, you don't need to make a constant current/voltage source since the load never changes. For a given load, you can only pick either the voltage or current you want through it, not both. If you pick voltage, the load will decide what the current will be. If you pick the current, the load will decide the voltage.
So your question makes no sense.