This function returns a resource constraint predicate whose operator(const IlcResourceConstraint& rc) returns IlcTrue if and only if rc has a variable representing the required or provided quantity of the required state. This member function returns IlcFalse if rc represents a virtual source or sink node (empty handle). This predicate is implemented using IlcResourceConstraint::isCapacityConstraint.

This functions exists with either an IloEnv or an IloSolver as argument.