This paragraph from `std::io::Read::read_ext()` applies to
*implementors* of `Read`. Since `AsyncReadExt` can't and shouldn't be
implemented outside of this crate, this documentation is unnecessary.
`tokio::test` and related macros now use the absolute path
`::core::prelude::v1::test` to refer to the built-in `test` macro.
This absolute path was introduced in rust-lang/rust#62086.
* io: Fix the Seek adapter and add a tested example.
If the first 'AsyncRead::start_seek' call returns Ready,
'AsyncRead::poll_complete' will be called.
Previously, a start_seek that immediately returned 'Ready' would cause
the Seek adapter to return 'Pending' without registering a Waker.
* fs: Do not return write errors from methods on AsyncSeek.
Write errors should only be returned on subsequent writes or on flush.
Also copy the last_write_err assert from 'poll_read' to both
'start_seek' and 'poll_complete' for consistency.
Jeb Rosen