Oh, heh, and I just released
All right. Now we have plenty to choose from.
It’s been a while since this thread was wrapped up, but I’ve been going through TWIR and have found that this feature has now been merged into nightly Rust as
Result::transpose(). Thanks to @cramertj for making the PR and to everyone else for working out the kinks in it!
And for reference #47338 is the tracking issue for stabilization.