[cluckindan]

This isn’t overloading the operator, it is replacing the implementation of type coercion when | is used with pipe() or asPipe() objects.

| itself still works exactly as before.

[whizzter]

Oh wait, looked at the source again, so it's some weird stateful collection thing triggered by the type coercion? By now I'm wishing that it was operator overloading.

[cluckindan]

Imagine the possibilities for control flow obfuscation when this trick is used with parentheses wrapping a part of the pipeline. :-)