Measurements
Measurements are returned in response to measurement gates. While the measurement result for a qubit is normally just a 0 or a 1 (or some other boolean convention), DQCsim allows additional information to be attached, and also allows an "undefined" state to model measurement failure. Measurement objects/handles are used to encapsulate this. Furthermore, since a single function call may have to return multiple measurements, measurement sets are defined as well.