Things I noticed while reviewing

[killercup]

⚠️ Targets #48's branch! Feel free to squash.

[killercup]

If nightly cargo was working, I'd've run clippy as well…

[colin-kiegel]

Nice, thank you. I like all suggestions. I have only one remark regarding #[deny(warnings)]. If I understand the impact correctly, this would also fail a build, where derive_builder is only a dependency. I would instead suggest something like #[cfg(test, deny(warnings)], or #[cfg(dev_nightly, deny(warnings)].

Both should fail travis builds, without uneccessarily impairing a cargo build for a consumer of derive_builder. I think it's important to expect new depreciations in rustc at anytime and I wouldn't like that to stop derive_builder from compiling.

I'm on the train and I will merge when I'm at home. :-)

[killercup]

If I understand the impact correctly, this would also fail a build, where derive_builder is only a dependency.

Not if I understand RFC 1193 correctly: Cargo automatically passes --cap-lints allow, check cargo clean; cargo build --verbose.

Both should fail travis builds

You mean our travis builds? We'd need to have a compile step for each sub crate, then (because of cap-lints). Nice CI script, btw, using case is a great idea!

Speaking of CI, the nightly stuff is currently broken because of rust-lang/cargo#3819.