Refactor/fix clippy lints

[shogo-nakano-desu]

As title says.

[lnicola]

Last time this came up (can't find the PR, though), it was pointed out that this is the most common variant, so boxing the contents will cause almost every instance to incur an allocation.

I don't know if this overhead will be larger than the speed-up obtained from the faster moves. Either way, I suspect it doesn't matter too much compared to the whole cargo check invocation.

[shogo-nakano-desu]

Ah, I see. I will keep it in my mind. Thank you for your review.

[shogo-nakano-desu]

@lnicola I have removed Box in
dd84306 . Thanks

[Veykril]

Thanks!
@bors r+
On that note, I believe the lints section in Cargo.toml has been set for stabilization now, rust-lang/cargo#12115 so we can soon enable clippy in general.

[bors]

📌 Commit dd84306 has been approved by Veykril

It is now in the queue for this repository.

[bors]

⌛ Testing commit dd84306 with merge 11ffcc0...

[bors]

☀️ Test successful - checks-actions
Approved by: Veykril
Pushing 11ffcc0 to master...