This function returns a resource constraint predicate whose operator(const IlcResourceConstraint& rc) returns IlcTrue if and only if rc indicates that one of a set of states of a state resource is required by the activity of the resource constraint. This member function returns IlcFalse if rc represents a virtual source or sink node (empty handle). This predicate is implemented using IlcResourceConstraint::isStateConstraint.

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