Originally posted by: Can Li

Hi folks,

I'm wondering if it is possible to deactivate and then activate (not remove and add again) an IloConstraint with C++ API by the name of the constraint.

For example, suppose I have

IloConstraint c2(expr>=0);

c2.setName("newconstraint");

model.add(c2);

Is it possible to deactivate "newconstraint"? Is it possible to make it active again after deactivating it?

Thanks in advance!

Best regards,

Can

First of all, if you only have the name and no reference to the constraint, then you have find back a reference to the constraint. This can be done by using an IloIterator and checking the name of each constraint. This is not very efficient, so if possible store a reference to the constraint, not its name.

Next, there are no facilities to deactivate a constraint. What you could do is to clear its left-hand side or set the right-hand side to infinity so that the constraint becomes redundant. Both are not recommended unless absolutely necessary.

Is there a particular reason you cannot remove/add the constraint?