# 0.3.1 (January 7, 2021)
### Added
- Added `layer_fn`, for constructing a `Layer` from a function taking
a `Service` and returning a different `Service` ([#491])
- Added an implementation of `Layer` for `&Layer` ([#446])
- Multiple documentation improvements ([#487], [#490])
[#491]: https://github.com/tower-rs/tower/pull/491
[#446]: https://github.com/tower-rs/tower/pull/446
[#487]: https://github.com/tower-rs/tower/pull/487
[#490]: https://github.com/tower-rs/tower/pull/490
# 0.3.0 (November 29, 2019)
- Move layer builder from `tower-util` to tower-layer.
# 0.3.0-alpha.2 (September 30, 2019)
- Move to `futures-*-preview 0.3.0-alpha.19`
- Move to `pin-project 0.4`
# 0.3.0-alpha.1 (September 11, 2019)
- Move to `std::future`
# 0.1.0 (April 26, 2019)
- Initial release