Accessing http2 pseudo-headers

[g2p]

I'm building a reverse proxy, and would like to pass on the request host to the downstream server.
With http/1.x, I can grab the HOST header.
With http/2, I should be able to grab the equivalent :authority pseudo-header from the header map, however it's invalid as a HeaderName so that doesn't work.
Grepping in h2 a bit it seems to do something with pseudo-headers including this one, but as far as I understand they are not exposed in hyper. The request uri also seems to not include the authority part in both protocols.
Am I missing something?

[g2p]

Oh, my bad: req.uri().authority() is set in HTTP/2. That's all I need!