After 6 years of the unwrap-infallible crate being out there without new releases, a GitHub issue was filed asking to bump to 1.0. Also, someone recently liked the old thread about it. Result::into_ok, which was meant to be the libcore realization of the same idea, is still unstable. So it seems the time is right.
Enjoy unwrap-infallible v1.0.0. The API (the part of it that is usable in stable Rust) is the same as in the previous release.