Class IlcAltResSet

An instance of the class IlcAltResSet represents a special set of resources to which activities can be assigned. When an activity requires an instance of this class, the activity requires exactly one of the resources represented in that set. For convenience, an instance of IlcAltResSet behaves like a standard resource. To that end, the class includes member functions that reproduce the properties and behavior of a standard resource.

The set of resources (the alternatives) must consist of capacity resources (that is, instances of IlcDiscreteEnergy, IlcDiscreteResource, IlcUnaryResource, or IlcReservoir).

Each resource in the set must be unique.

In case the elements of the set of alternative resources do not conform to these rules, an error will be raised when the set is constructed.

If you change the resources in the set during its use, you will produce unpredictable behavior; in fact, such changes may lead to erroneous behavior.

Redundant Resources

It is possible to consider the set of resources as a resource whose theoretical capacity is the sum of the capacities of the resources of the set. Let us call this resource the redundant resource of the set.

An alternative resource constraint on the set is a resource constraint on this redundant resource. Therefore, posting the timetable constraint or the edge finder constraint on the redundant resource may lead to more efficient propagation. Global and resource constraints on the redundant resource have exactly the same purpose as a redundant constraint in a Solver model.

Notice that if the resources of the set are instances of IlcUnaryResource and if they have strictly identical properties (the activities have the same processing time, do not require any other resources, and there is no transition time), the redundant resource gives exactly the same solution as the alternative resource. In such a case, it is more efficient to represent the set of unary resources with a single discrete resource rather than with a alternative resource set.

Printing or Displaying Sets of Resources

The printed representation of an instance of the class IlcAltResSet consists of its name, followed by the list of resources. If there are more than 10 resources, only the number of resources is displayed. For example:

[r1, r2, r3] represents a set of resources containing the three resources r1, r2, and r3.

[size = 14] represents a set of resources containing 14 resources.

If the Solver trace is active and the resource is not named, the string "IlcAltResSet" is followed by the address of the implementation object. The address will be enclosed in parentheses.

This constructor creates a new instance of IlcAltResSet and adds it to those managed by schedule. The size of the set (that is, the number of alternative capacity resources) is indicated by size. Before you use the new instance, you must initialize its set with instances of capacity resources.

This constructor creates a new instance of IlcAltResSet and adds it to those managed by schedule. The constructor initializes the set with the resources of the resource array passed as argument.

This member function closes the invoking object; that is, it closes all the resources present in the invoking instance of IlcAltResSet.

This member function returns IlcTrue if resource belongs to the invoking instance of IlcAltResSet. Otherwise, it returns IlcFalse.

This member function returns the index of resource in the invoking alternative capacity resource set.

This member function returns the redundant resource of the invoking set, if it has been previously created.

This member function returns the schedule to which the invoking instance of IlcAltResSet belongs. Each alternative resource in the set belongs to the same schedule, an instance of IlcSchedule.

This member function returns the number of alternative capacity resources in the invoking instance of IlcAltResSet.

This member function returns an instance of IloSolver associated with the invoking object.

This member function returns a pointer to the implementation object of the solver where the invoking object was extracted.

This member function returns IlcTrue if the redundant resource of the invoking set has been created. Otherwise, it returns IlcFalse.

This member function returns IlcTrue if all of the capacity resources in the set of the invoking instance of IlcAltResSet have been closed. The member function returns IlcFalse otherwise.

This member function builds the redundant resource associated with the invoking alternative resources set. When the redundant resource is created, the resource constraints on the resources of the set and the alternative resource constraints of the set are automatically added to the redundant resource. If the argument timetable is set to IlcTrue, the timetable constraint is added to the redundant resource.

This operator returns IlcTrue if the invoking instance and the argument resource are not identical; that is, they are handles of different implementation objects. Otherwise, it returns IlcFalse.

This operator returns IlcTrue if the invoking instance and the argument resource are identical; that is, they are both handles with the same implementation object. Otherwise, it returns IlcFalse.

This operator returns a reference to the resource located at index in the invoking alternative resource set.

The call to this member function confirms that all alternative resources were added to the invoking alternative resource set. After calling this member function, no resources can be added to the set.

The use of this member function is mandatory only for alternative resource sets constructed on durable schedules.