https://github.com/rust-lang/rust/blob/4ce08a5d70a4dfc4da7ed0bc0098cfd2176b8411/src/libcore/iter.rs#L1014 vs. https://github.com/rust-lang/rust/blob/4ce08a5d70a4dfc4da7ed0bc0098cfd2176b8411/src/libcore/iter.rs#L1373 Accidental mismatch? cc @alexcrichton, @aturon