There are two different implementation of Try trait for Poll type;
Poll<Result<T, E>> and Poll<Option<Result<T, E>>>. Take them into
account when generating suggestions.
For example, for Err(e)? suggest either return Poll::Ready(Err(e)) or
return Poll::Ready(Some(Err(e))) as appropriate.
Fix FP for `suspicious_arithmetic_impl` from `suspicious_trait_impl` …
As discussed in #3215, the `suspicious_trait_impl` lint causes too many false positives, as it is complex to find out if binary operations are suspicious or not.
This PR restricts the number of binary operations to at most one, otherwise we don't lint.
This can be seen as very conservative, but at least FP can be reduced to bare minimum.
Fixes: #3215
changelog: limit the `suspicious_arithmetic_impl` lint to one binop, to avoid many FPs
Ignore not really redundant clones of ManuallyDrop
"Redundant" clones of `ManuallyDrop` are sometimes used for the side effect of
invoking the clone, without running the drop implementation of the inner type.
In other words, they aren't really redundant. For example, futures-rs crate:
```rust
#[allow(clippy::redundant_clone)] // The clone here isn't actually redundant.
unsafe fn increase_refcount<T: ArcWake>(data: *const ()) {
// Retain Arc, but don't touch refcount by wrapping in ManuallyDrop
let arc = mem::ManuallyDrop::new(Arc::<T>::from_raw(data as *const T));
// Now increase refcount, but don't drop new refcount either
let _arc_clone: mem::ManuallyDrop<_> = arc.clone();
}
```
changelog: Ignore redundant clone lint for ManuallyDrop.
"Redundant" clones of `ManuallyDrop` are sometimes used for the side effect of
invoking the clone, without running the drop implementation of the inner type.
In other words, they aren't really redundant. For example, futures-rs crate:
```rust
#[allow(clippy::redundant_clone)] // The clone here isn't actually redundant.
unsafe fn increase_refcount<T: ArcWake>(data: *const ()) {
// Retain Arc, but don't touch refcount by wrapping in ManuallyDrop
let arc = mem::ManuallyDrop::new(Arc::<T>::from_raw(data as *const T));
// Now increase refcount, but don't drop new refcount either
let _arc_clone: mem::ManuallyDrop<_> = arc.clone();
}
```
Ignore redundant clone lint for ManuallyDrop.
Panic multiple args
changelog: Fixes bug with `panic` lint reported in #5767. I also did the same changes to the lints for `todo`, `unimplemented` and `unreachable`, so those lints should now also detect calls to those macros with a message.
improve advice in iter_nth_zero
fixes#5783
*Please keep the line below*
changelog: For iter_nth_zero, the "use .next()" replacement advice is on the last line of the code snippet, where it is vulnerable to truncation. Display that advice at the beginning instead.
This lint catches cases where the last statement of a closure expecting
an instance of Ord has a trailing semi-colon. It compiles since the
closure ends up return () which also implements Ord but causes
unexpected results in cases such as sort_by_key.
Fixes#5080
reprise: rebase, update and address all concerns
Rename collapsable_if fix suggestion to "collapse nested if block"
The name "try" is confusing when shown as quick fix by rust-analyzer
changelog: Rename `collapsable_if` fix suggestion to "collapse nested if block"
The "use .next()" replacement advice is on the last line of the code snippet,
where it is vulnerable to truncation. Display that advice at the beginning
instead.
closes#5783
Move range_minus_one to pedantic
This moves the range_minus_one lint to the pedantic category, so there
will not be any warnings emitted by default. This should work around
problems where the suggestion is impossible to resolve due to the range
consumer only accepting a specific range implementation, rather than the
`RangeBounds` trait (see #3307).
While it is possible to work around this by extracting the boundary into
a variable, I don't think clippy should encourage people to disable or
work around lints, but instead the lints should be fixable. So hopefully
this will help until a proper implementation checks what the range is
used for.
*Please keep the line below*
changelog: move [`range_minus_one`] to pedantic
Some accuracy lints for floating point operations
This will add some lints for accuracy on floating point operations suggested by @clarfon in #2040 (fixes#2040).
These are the remaining lints:
- [x] x.powi(2) => x * x
- [x] x.logN() / y.logN() => x.logbase(y)
- [x] x.logbase(E) => x.log()
- [x] x.logbase(10) => x.log10()
- [x] x.logbase(2) => x.log2().
- [x] x * PI / 180 => x.to_radians()
- [x] x * 180 / PI => x.to_degrees()
- [x] (x + 1).log() => x.log_1p()
- [x] sqrt(x * x + y * y) => x.hypot(y)
changelog: Included some accuracy lints for floating point operations
Stabilize `transmute` in constants and statics but not const fn
cc #53605 (leaving issue open so we can add `transmute` to `const fn` later)
Previous attempt: #64011
r? @RalfJung
cc @rust-lang/wg-const-eval
new lint: match_like_matches_macro
Suggests using the `matches!` macro from `std` where appropriate.
`redundant_pattern_matching` has been moved into the `matches` pass to allow suppressing the suggestion where `is_some` and friends are a better replacement.
changelog: new lint: `match_like_matches_macro`
single_match_else - single expr/stmt else block corner case
One approach to fix#3489.
See discussion in the issue.
changelog: single_match_else - single expr/stmt else block corner case fix
