doc: make the usage of clippy.toml more clear
Added a subsection for it, and move it after `Allowing/denying lints` which is more frequently used.
fix https://github.com/rust-lang/rust-clippy/issues/9265
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: none
[`unnecessary_lazy_evaluations`] Do not suggest switching to early evaluation when type has custom `Drop`
fix#9427
changelog: [`unnecessary_lazy_evaluations`] Do not suggest switching to early evaluation when type has custom `Drop`
fix [`needless_borrow`], [`explicit_auto_deref`] FPs on unions
fix https://github.com/rust-lang/rust-clippy/issues/9383
changelog: fix [`needless_borrow`] false positive on unions
changelog: fix [`explicit_auto_deref`] false positive on unions
Left a couple debug derived impls on purpose I needed to debug as I don't think it's noise
Don't lint unstable moves in `std_instead_of_core`
Fixes#9515
changelog: [`std_instead_of_core`]: No longer suggests unstable modules such as `core::error`
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
