fix nightly clippy warnings #991

This will avoid breaking CI on new releases of clippy. It also makes the code a little easier to read. - Convert `match val { pat => true, _ => false }` to `matches!(val, pat)` - Remove unnecessary closures - Convert `self: &mut Self` to `&mut self` This bumps the MSRV to 1.42.0 for `matches!`. The latest version of rust is 1.46.0, so as per https://github.com/tokio-rs/tracing#supported-rust-versions this is not considered a breaking change. I didn't fix the following error because the fix was not trivial/needed a decision: ``` warning: you are deriving `Ord` but have implemented `PartialOrd` explicitly --> tracing-subscriber/src/filter/env/field.rs:16:32 | 16 | #[derive(Debug, Eq, PartialEq, Ord)] | ^^^ | = note: `#[warn(clippy::derive_ord_xor_partial_ord)]` on by default note: `PartialOrd` implemented here --> tracing-subscriber/src/filter/env/field.rs:98:1 | 98 | / impl PartialOrd for Match { 99 | | fn partial_cmp(&self, other: &Self) -> Option<Ordering> { 100 | | // Ordering for `Match` directives is based first on _whether_ a value 101 | | // is matched or not. This is semantically meaningful --- we would ... | 121 | | } 122 | | } | |_^ = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#derive_ord_xor_partial_ord ```

For the next person that comes along, the way to do this automatically is ```sh rg 'version is 1\.40' -l | xargs sed -i 's/version is 1\.40/version is 1.42/' ```

``` fd '.(md|rs)' | xargs rg '1\.40' -l | xargs sed -i 's/1\.40/1.42/' ```

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

fix nightly clippy warnings #991

fix nightly clippy warnings #991

Commits on Sep 29, 2020