Make clone_on_copy lint machine applicable

[jyn514]

Copy/pasted from rust-lang/rustfix#182:

This gives a warning instead of replacing it with the suggested code:

$ cargo +nightly fix -Z unstable-options --clippy
warning: using `clone` on a `Copy` type
   --> src/parse/mod.rs:258:27
    |
258 |                 location: self.next_location().clone(),
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try dereferencing it: `*self.next_location()`

It would be really nice to have this be done automatically, since I currently have about 20 of these warnings in my code.

$ cargo +nightly --version
cargo 1.40.0-nightly (5da4b4d47 2019-10-28)
$ cargo +nightly clippy -V
clippy 0.0.212 (b4f17697 2019-11-14)

[jyn514]

cc @Manishearth

[flip1995]

In theory the suggestion is already fixable by rustfix:

rust-clippy/clippy_lints/src/methods/mod.rs

Lines 1721 to 1725 in 86b8643

	span_lint_and_then(cx, CLONE_ON_COPY, expr.span, "using `clone` on a `Copy` type", |db| {
	if let Some((text, snip)) = snip {
	db.span_suggestion(expr.span, text, snip, Applicability::Unspecified);
	}
	});

Only thing left to do here is to figure out the applicability level. (And maybe pass it through the snippet_with_applicability function)

[Manishearth]

Also write rustfix tests, we should avoid having any fixable lints without tests

…

On Mon, Nov 18, 2019, 3:00 PM Philipp Krones ***@***.***> wrote: In theory the suggestion is already fixable by rustfix: https://github.com/rust-lang/rust-clippy/blob/86b8643586aa39f36fb7a02e98c8d64d31415e70/clippy_lints/src/methods/mod.rs#L1721-L1725 Only thing left to do here is to figure out the applicability level. (And maybe pass it through the snippet_with_applicability function) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#4826?email_source=notifications&email_token=AAMK6SH7JFBWLXYZ27YQ7GTQUMNADA5CNFSM4JOZMRIKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEEMHDPA#issuecomment-555250108>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAMK6SF2ABR5YXTALAG3I3TQUMNADANCNFSM4JOZMRIA> .