Comparing these function references: `a_inc_instance.value === b_inc_instance.value` is true in javascript when the function `value` is a class method. In the

Comparing these function references: `a_inc_instance.value === b_inc_instance.value` is true in javascript when the function `value` is a class method. In the closure/factory created version it is false - each function `value` is a different instance with a different reference. That will involve unnecessary duplication in the interpreter, but also allows for the function to be optimised for its state (monomorphic etc) which can be significant when more than a simple example `x++` operation is involved. So the class version does entail less memory usage, but the closure permits more JIT optimisation. > If it were a class instance you could ask instance.constructor.name to find out that it's an Incrementer, so you can grep for `class Incrementer`. Im not sure how much extra help that kind of thing is, we might instead grep for `symbol\s*=` to find where a symbol was assigned whether it had a .constructor.name property or not. I can see it is a general advantage of having more types, to have summary information besides the names.