[nvader]

I'll add another cautionary word in with everyone else who is panning this implementation.

This is just using operator overloading to determine keywords, but it locks you out of ever using the same type twice in your signature. Notice that :usd turns into a name. What?

This is cute, but has no place in a professional software interface.

[culi]

> but it locks you out of ever using the same type twice in your signature.

I don't see how you drew that conclusion. It seems to me the author provided several examples of this not being the case. Care to elucidate?