I thought the very same when writing the specs.

```ruby
expect { }.to output("foo").to_stdout
```

reads better that what we have now. I would probably do it in a separate PR if you're OK with it. Actually, having the opportunity to do something like

```ruby
expect { }.to output("foo").to(some_alternate_stream)
```

looks pretty awesome to me even though the implementation can be tricky I think. And we can do it as a last step of a new pull request (this way I'll get your feedback on the way to the implementation :))