add `box-default` lint
This adds a `box-default` lint to suggest using `Box::default()` instead of `Box::new(Default::default())`, which offers less moving parts and potentially better performance according to [the perf book](https://nnethercote.github.io/perf-book/standard-library-types.html#box).
---
changelog: add [`box_default`] lint
[`needless_return`] Recursively remove unneeded semicolons
fix#8336,
fix#8156,
fix https://github.com/rust-lang/rust-clippy/issues/7358,
fix#9192,
fix https://github.com/rust-lang/rust-clippy/issues/9503
changelog: [`needless_return`] Recursively remove unneeded semicolons
For now the suggestion about removing the semicolons are hidden because they would be very noisy and should be obvious if the user wants to apply the lint manually instead of using `--fix`. This could be an issue for beginner, but haven't found better way to display it.
[arithmetic-side-effects] Consider references
Takes into consideration integer references like `&i32::MAX` because currently things like `let _ = &1 + 0` trigger the lint.
changelog: FP: [`arithmetic_side_effects`]: Now ignores references
[9507](https://github.com/rust-lang/rust-clippy/pull/9507)
Don't lint `*_interior_mutable_const` on unions due to potential ICE.
fixes#9445
cc rust-lang/rust#101113
This started ICE'ing sometime last month due to stricter UB checks. I'm not sure how we could check the value of a union as MIRI doesn't seem to store which field is currently active.
changelog: Don't ICE on const unions containing a `!Freeze` type.
Silence [`question_mark`] in const context
fix https://github.com/rust-lang/rust-clippy/issues/9175
When `const_try` is stabilised can be turned into a MSRV
changelog: Silence [`question_mark`] in const context
new uninlined_format_args lint to inline explicit arguments
Implement https://github.com/rust-lang/rust-clippy/issues/8368 - a new lint to inline format arguments such as `print!("{}", var)` into `print!("{var}")`.
### Supported cases
code | suggestion | comment
---|---|---
`print!("{}", var)` | `print!("{var}")` | simple variables
`print!("{0}", var)` | `print!("{var}")` | positional variables
`print!("{v}", v=var)` | `print!("{var}")` | named variables
`print!("{0} {0}", var)` | `print!("{var} {var}")` | aliased variables
`print!("{0:1$}", var, width)` | `print!("{var:width$}")` | width support
`print!("{0:.1$}", var, prec)` | `print!("{var:.prec$}")` | precision support
`print!("{:.*}", prec, var)` | `print!("{var:.prec$}")` | asterisk support
### Known Problems
* There may be a false positive if the format string is wrapped in a macro call:
```rust
# let var = 42;
macro_rules! no_param_str { () => { "{}" }; }
macro_rules! pass_through { ($expr:expr) => { $expr }; }
println!(no_param_str!(), var);
println!(pass_through!("{}"), var);
```
* Format string uses an indexed argument that cannot be inlined.
Supporting this case requires re-indexing of the format string.
Until implemented, `print!("{0}={1}", var, 1+2)` should be changed to `print!("{var}={0}", 1+2)` by hand.
changelog: [`uninlined_format_args`]: A new lint to inline format arguments, i.e. `print!("{}", var)` into `print!("{var}")`
Stabilize const `BTree{Map,Set}::new`
The FCP was completed in #71835.
Since `len` and `is_empty` are not const stable yet, this also creates a new feature for them since they previously used the same `const_btree_new` feature.
Implement https://github.com/rust-lang/rust-clippy/issues/8368 - a new
lint to inline format arguments such as `print!("{}", var)` into
`print!("{var}")`.
code | suggestion | comment
---|---|---
`print!("{}", var)` | `print!("{var}")` | simple variables
`print!("{0}", var)` | `print!("{var}")` | positional variables
`print!("{v}", v=var)` | `print!("{var}")` | named variables
`print!("{0} {0}", var)` | `print!("{var} {var}")` | aliased variables
`print!("{0:1$}", var, width)` | `print!("{var:width$}")` | width
support
`print!("{0:.1$}", var, prec)` | `print!("{var:.prec$}")` | precision
support
`print!("{:.*}", prec, var)` | `print!("{var:.prec$}")` | asterisk
support
code | suggestion | comment
---|---|---
`print!("{0}={1}", var, 1+2)` | `print!("{var}={0}", 1+2)` | Format
string uses an indexed argument that cannot be inlined. Supporting this
case requires re-indexing of the format string.
changelog: [`uninlined_format_args`]: A new lint to inline format
arguments, i.e. `print!("{}", var)` into `print!("{var}")`
Fix ICE in `needless_pass_by_value` with unsized `dyn Fn`
fixes#9459
Not really sure why a query for a type implementing `FnOnce` even works since the trait if `FnOnce<T>`, but it seems to. I would have expected it to crash like it does when passing `dyn FnOnce()` as the type.
changelog: [`needless_pass_by_value`](https://rust-lang.github.io/rust-clippy/master/#needless_pass_by_value) Fix ICE in with unsized `dyn Fn` argument
fix a ui test
use `into`
fix clippy ui test
fix a run-make-fulldeps test
implement `IntoQueryParam<DefId>` for `OwnerId`
use `OwnerId` for more queries
change the type of `ParentOwnerIterator::Item` to `(OwnerId, OwnerNode)`
fallout2: rework clippy_dev & _lints fmt inlining
Continuing #9525 -- a few more inlining, but this time with some code changes to simplify format strings:
* Inline format args where possible
* simplify a few complex macros into format str
* use formatdoc!() instead format!(indoc!(...))
changelog: none
cc: `@llogiq`
Always print '_, even for erased lifetimes.
Explicit lifetime arguments are now the recommended syntax in rust 2018 and rust 2021. This PR applies this discipline to rustc itself.
Since clippy can use a projects MSRV for its lints, it might not want
to consider functions as const stable if they have been added lately.
Functions that have been stabilized this version use
CURRENT_RUSTC_VERSION as their version, which gets then turned into the
current version, which might be something like `1.66.0-dev`. The version
parser cannot deal with this version, so it has to be stripped off.
Since `len` and `is_empty` are not const stable yet, this also
creates a new feature for them since they previously used the same
`const_btree_new` feature.
[`never_loop`]: Fix FP with let..else statements.
Fixes#9356
This has been bugging me for a while, so I thought I'd take a stab at it! I'm completely uncertain about the quality of my code, but I think it's an alright start, so opening this PR to get some feedback from more experienced clippy people :)
changelog: [`never_loop`]: Fix FP with let..else statements
Introduce mir::Unevaluated
Previously the distinction between unevaluated constants in the type-system and in mir was not explicit and a little confusing. Probably better to introduce its own type for that.
r? `@lcnr`
[`nonstandard_macro_braces`] Do not modify macro arguments
fix#9498
based on top of https://github.com/rust-lang/rust-clippy/pull/9471
Also simplify the lint by not caring about code format which should be `rustfmt` job, and turn the lint into machine Applicable
changelog: Suggestion: [`nonstandard_macro_braces`]: The suggestion is now machine applicable and will no longer replace brackets inside the macro argument.
[#9499](https://github.com/rust-lang/rust-clippy/pull/9499)
Changelog for Rust 1.64 🍎
The normal release preparation dance. I've written the changelog like the version has already been released. The PR can be approved and then merged by anyone after the release of Rust 1.64 🙃
---
changelog: none
