In this code:

```
people = [ p1, p2, p3 ]
people.map { |p| p.age }.max

```

* Isn't this code creating an array and then calling `max` on it?
* Isn't this the waste of memory because of a redundant array
created by `map` method?
* Couldn't we just call `max` on any enumerators and compute
the maximum on the fly?