having problem with `std.algorithm.each`

[ref2401 via Digitalmars-d-learn]

It seems like `std.algorithm.each` is not executed in the example 
below.
Could anyone tell why?
Thank you.

import std.algorithm;

void main(string[] args) {
        int[] arr = [1, 2, 3, 4, 5];

        arr.each!((ref e) => {
                writeln(e); // does not print
                ++e;
        })();

        writeln(arr); // prints [1, 2, 3, 4, 5]
}