(wangle) set* should not invalidate getFuture
Summary: @jcoens observed in
D1451114 that it was unintuitive that you have to retrieve the `Future` before fulfilling the `Promise`. That seemed wrong to me too, but sure enough when I wrote the unit tests that doesn't work (throws "promise already fulfilled" when you call `getFuture`). I think this is just a simple mistake, but I'm going to carefully look at the output of contbuild test suites before committing.
Test Plan:
red-green
careful dependency unit test inspection
Reviewed By: jon.coens@fb.com
Subscribers: net-systems@, fugalh, exa, jcoens
FB internal diff:
D1453780
projects / folly.git / commit