warning: field `0` is never read
  --> src/directory/watch_event_router.rs:35:24
   |
35 | pub struct WatchHandle(Arc<WatchCallback>);
   |            ----------- ^^^^^^^^^^^^^^^^^^
   |            |
   |            field in this struct
   |
   = note: `WatchHandle` has a derived impl for the trait `Clone`, but this is intentionally ignored during dead code analysis
help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
   |
35 | pub struct WatchHandle(());
   |                        ~~

warning: field `0` is never read
  --> src/directory/directory.rs:43:26
   |
43 | pub struct DirectoryLock(Box<dyn Send + Sync + 'static>);
   |            ------------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |            |
   |            field in this struct
   |
   = note: `#[warn(dead_code)]` on by default
help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
   |
43 | pub struct DirectoryLock(());
   |                          ~~

warning: this `.into_iter()` call is equivalent to `.iter_mut()` and will not consume the `slice`
   --> columnar/src/column_values/mod.rs:105:14
    |
105 |             .into_iter()
    |              ^^^^^^^^^ help: call directly: `iter_mut`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#into_iter_on_ref

warning: this `.into_iter()` call is equivalent to `.iter_mut()` and will not consume the `slice`
  --> columnar/src/column_values/mod.rs:78:14
   |
78 |             .into_iter()
   |              ^^^^^^^^^ help: call directly: `iter_mut`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#into_iter_on_ref
   = note: `#[warn(clippy::into_iter_on_ref)]` on by default