Before this fix, the lint had a false positive, namely when a reference
was taken to a field when the field operand implements a custom Drop.
The compiler will refuse to partially move a type that implements Drop,
because that would put the operand in a weird state. See added
regression test.
`option_if_let_else`: do not trigger on expressions returning `()`
Fix#11893
Trigerring on expressions returning `()` uses the arguments of the `map_or_else()` rewrite only for their side effects. This does lead to code which is harder to read than the original.
changelog: [`option_if_let_else`]: do not trigger on unit expressions
add lint against unit tests in doctests
During RustLab, Alice Ryhl brought to my attention that the Andoid team stumbled over the fact that if one attempts to write a unit test within a doctest, it will be summarily ignored. So this lint should help people wondering why their tests won't run.
---
changelog: New lint: [`test_attr_in_doctest`]
[#11872](https://github.com/rust-lang/rust-clippy/pull/11872)
Fix#11893
Trigerring on expressions returning `()` uses the arguments of the
`map_or_else()` rewrite only for their side effects. This does lead
to code which is harder to read than the original.
[`redundant_guards`]: catch `is_empty`, `starts_with` and `ends_with` on slices and `str`s
Fixes#11807
Few things worth mentioning:
- Taking `snippet`s is now done at callsite, instead of passing a span and doing it in `emit_redundant_guards`. This is because we now need custom suggestion strings in certain places, like `""` for `str::is_empty`.
- This now uses `snippet` instead of `snippet_with_applicability`. I don't think this really makes any difference for `MaybeIncorrect`, though?
- This could also lint byte strings, as they're of type `&[u8; N]`, but that can be ugly so I decided to leave it out for now
changelog: [`redundant_guards`]: catch `str::is_empty`, `slice::is_empty`, `slice::starts_with` and `slice::ends_with`
Add `never_patterns` feature gate
This PR adds the feature gate and most basic parsing for the experimental `never_patterns` feature. See the tracking issue (https://github.com/rust-lang/rust/issues/118155) for details on the experiment.
`@scottmcm` has agreed to be my lang-team liaison for this experiment.
[`redundant_closure_call`]: avoid duplicated `async` keyword when triggering on closure that returns `async` block
close#11357
----
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`redundant_closure_call`]: avoid duplicated `async` keyword when triggering on closure that returns `async` block
- Rename them both `as_str`, which is the typical name for a function
that returns a `&str`. (`to_string` is appropriate for functions
returning `String` or maybe `Cow<'a, str>`.)
- Change `UnOp::as_str` from an associated function (weird!) to a
method.
- Avoid needless `self` dereferences.
Don't suggest `a.mul_add(b, c)` if parameters are not float
clippy::suboptimal_flops used to not check if the second parameter to f32/f64.mul_add() was float. Since the method is only defined to take `Self` as parameters, the suggestion was wrong.
Fixes#11831
changelog: [`suboptimal_float`]: Don't suggest `a.mul_add(b, c)` if parameters are not f32/f64
[`ptr_arg`]: recognize methods that also exist on slices
Fixes#11816
Not a new lint, just a very small improvement to the existing `ptr_arg` lint which would have caught the linked issue.
The problem was that the lint checks if a `Vec`-specific method was called, that is, if the receiver is `Vec<_>`.
This is the case for `len` and `is_empty`, however these methods also exist on slices so we can still lint there.
This logic exists in a different lint, so we can just reuse that here.
Interestingly, there was even a comment up top that explained what it should have been doing, but the logic for it just wasn't there?
changelog: [`ptr_arg`]: recognize methods that also exist on slices
<sub>Also, this is my 100th PR to clippy 🎉 </sub>
`manual_try_fold`: check that `fold` is really `Iterator::fold`
Fix#11876
changelog: [`manual_try_fold`]: suggest using `try_fold` only for `Iterator::fold` uses
Move `implied_bounds_in_impls` back to complexity
This lint was originally in the complexity category when I PR'd it. It was then moved to nursery by me due to a number of issues (a false positive, an invalid suggestion and an ICE), but that was probably an overreaction and all of the issues were fixed quickly after.
This is a useful lint imo and there hasn't been any issues with it in a few months, so I say we should give it another try and move it back to complexity.
I did a lintcheck run on the top 400 crates and all of them are legitimate, with 18 warnings. Most of them are from anstyle having a `impl Display + Copy + Clone` return type, or the bitvec crate with a return type like `impl Iterator + DoubleEndedIterator`.
changelog: Move [`implied_bounds_in_impls`] to `complexity` (Now warn-by-default)
[#11867](https://github.com/rust-lang/rust-clippy/pull/11867)
Fix `box_default` behaviour with empty `vec![]` coming from macro arg
Fix#11868
changelog: [`box_default`]: do not warn on `Box::new(vec![])` if the `vec![]` comes from a macro argument
Create new lint `option_map_or_err_ok`
Fixes#10045.
For the following code:
```rust
let opt = Some(1);
opt.map_or(Err("error"), Ok);
```
It suggests to instead write:
```rust
let opt = Some(1);
opt.ok_or("error");
```
r? `@flip1995`
changelog: Create new lint `option_map_or_err_ok`
suggest alternatives to iterate an array of ranges
works towards #7125
changelog: [`single_element_loop`]: suggest better syntax when iterating over an array of a single range
`@thinkerdreamer` and myself worked on this issue during a workshop by `@llogiq` at the RustLab 2023 conference. It is our first contribution to clippy.
When iterating over an array of only one element, _which is a range_, our change suggests to replace the array with the contained range itself. Additionally, a hint is printed stating that the user probably intended to iterate over the range and not the array. If the single element in the array is not a range, the previous suggestion in the form of `let {pat_snip} = {prefix}{arg_snip};{block_str}`is used.
This change lints the array with the single range directly, so any prefixes or suffixes are covered as well.
