Class IloPrecedenceConstraint

Definition file: ilsched/iloactivity.h

Include file: <ilsched/iloscheduler.h>

Instances of the class IloPrecedenceConstraint are temporal constraints. These temporal constraints express precedence between activities in a schedule. (Other temporal constraints—instances of IloTimeBoundConstraint—express constraints on the time interval in which an activity is to be scheduled.)

This class inherits from the IBM ILOG Concert Technology class IloConstraint. That class is documented in the IBM ILOG Concert Technology Reference Manual.

Instances of this class are created by these member functions:

For more information, see IloConstraint in the IBM ILOG Concert Technology Reference Manual, and Temporal Relations.

Constructor Summary
`public`	`IloPrecedenceConstraint()`
`public`	`IloPrecedenceConstraint(IloPrecedenceConstraintI * impl)`

Method Summary
`public IloNum`	`getDelay() const`
`public IloNumVar`	`getDelayVariable() const`
`public IloActivity`	`getFollowingActivity() const`
`public IloPrecedenceConstraintI *`	`getImpl() const`
`public IloActivity`	`getPrecedingActivity() const`
`public IloPrecedenceConstraintType`	`getType() const`
`public IloBool`	`hasDelayVariable() const`

IloPrecedenceConstraint

public IloPrecedenceConstraint()

This constructor creates an instance that is empty, that is, one whose handle pointer is null. You must assign it a value before you access it. Any attempt to access it before assignment leads to undefined behaviour.

IloPrecedenceConstraint

public IloPrecedenceConstraint(IloPrecedenceConstraintI * impl)

This constructor creates an instance of the handle class from the pointer to an instance of the implementation class.

Method Detail

getDelay

public IloNum getDelay() const

This member function returns the delay of the invoking precedence constraint.

Example

The statement

m.add(act2.startsAfterEnd(act1, delay));

posts the constraint that at least the given delay must elapse between the end of the preceding activity act1 and the start of the following activity act2.

getDelayVariable

public IloNumVar getDelayVariable() const

Returns the variable delay that the constraint was build with. Should not be called if the constraint has been build with a constant delay. Will assert in this case if we are in debug mode.

This member function returns the delay variable of the invoking precedence constraint.

This member function returns IloTrue if the invoking precedence constraint has a delay variable. Otherwise, if the delay is constant, it returns IloFalse.