nikic/iter — pull request #22 by yuya-takeyama (2014-10-01 16:59:30+00:00)
Title: Add ** operator

It's useful like this.

```php
iter\toArray(iter\map(iter\fn\operator('**', 2), iter\range(1, 10)));
// => [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
```