Add a new lint `doc_overindented_list_items` to detect and fix list items
in docs that are overindented.
For example,
```rs
/// - first line
/// second line
fn foo() {}
```
this would be fixed to:
```rs
/// - first line
/// second line
fn foo() {}
```
This lint improves readabiliy and consistency in doc.
fix#14034
The currect implementation of `obfuscated_if_else` sometimes makes
incorrect suggestions when the original code have side effects (see the
example in the above issue). I think this can be fixed by changing the
applicability depending on whether it can have side effects or not.
changelog: [`obfuscated_if_else`]: change applicability when the
original code can have side effects
Removing the `.as_ref()` or `.as_mut()` as the top-level expression in a
closure may change the type of the result. In this case, it may be
better not to lint rather than proposing a fix that would not work.
I opened https://github.com/rust-lang/rust-clippy/pull/13896 before.
However, I found that there're more cases where Clippy suggests to use
modules that belong to the `std` crate even in a `no_std` environment.
Therefore, this PR include the changes I've made in #13896 and new
changes to fix cases I found this time to prevent wrong suggestions in
`no_std` environments as well.
changelog: [`redundant_closure`]: correct suggestion in `no_std`
changelog: [`repeat_vec_with_capacity`]: correct suggestion in `no_std`
changelog: [`single_range_in_vec_init`]: don't emit suggestion to use
`Vec` in `no_std`
changelog: [`drain_collect`]: correct suggestion in `no_std`
changelog: [`map_with_unused_argument_over_ranges`]: correct suggestion
in `no_std`
also close#13895
Uplift `clippy::double_neg` lint as `double_negations`
Warns about cases like this:
```rust
fn main() {
let x = 1;
let _b = --x; //~ WARN use of a double negation
}
```
The intent is to keep people from thinking that `--x` is a prefix decrement operator. `++x`, `x++` and `x--` are invalid expressions and already have a helpful diagnostic.
I didn't add a machine-applicable suggestion to the lint because it's not entirely clear what the programmer was trying to achieve with the `--x` operation. The code that triggers the lint should always be reviewed manually.
Closes#82987
Receivers which are references to `Option` and `Result`, or who
implement `Deref` to one of those types, will be linted as well.
changelog: [`unnecessary_map_or`]: work with ref and `Deref` to `Option`
and `Result` as well
Fixes#14023
**Note:** this patch must be merged after #13998 – only the second
commit must be reviewed, the first one repeats the patch in #13998 for
mergeability reasons.
Get rid of `mir::Const::from_ty_const`
This function is strange, because it turns valtrees into `mir::Const::Value`, but the rest of the const variants stay as type system consts.
All of the callsites except for one in `instsimplify` (array length simplification of `ptr_metadata` call) just go through the valtree arm of the function, so it's easier to just create a `mir::Const` directly for those.
For the instsimplify case, if we have a type system const we should *keep* having a type system const, rather than turning it into a `mir::Const::Value`; it doesn't really matter in practice, though, bc `usize` has no padding, but it feels more principled.
part of https://github.com/rust-lang/rust-clippy/issues/9100
The `obfuscated_if_else` lint currently only triggers for the pattern
`.then_some(..).unwrap_or(..)`, but there're other cases where this lint
should be triggered, one of which is `.then(..).unwrap_or(..)`.
changelog: [`obfuscated_if_else`]: trigger lint for the
`.then(..).unwrap_or(..)` pattern as well
changelog: none
`x & 15 == 0` is not equivalent to `x.trailing_zeros() > 4`, as `x =
0b10000` is true for the former and false for the latter.
In fact, clippy itself suggests the following:
```rust
pub fn src(x: i32) -> bool {
x & 15 == 0 // ~error: bit mask could be simplified with a call to `trailing_zeros`
^^^^^^^^^^^ help: try: `x.trailing_zeros() >= 4`
}
```
I ran across this message while writing code and thought it was quite
odd. I've simplified it and hopefully made it clearer for non-native
English speakers.
changelog: clarify message for non-obvious precedence
`manual_ok_or` covers the same case that were covered by
`option_map_or_err_ok` which is not deprecated. The latter was in the
"style" category. Also, the lint is machine applicable, and leads to
shorter and more readable code, so "style" is appropriate.
The only difference is that the η-expanded form of `Result::Ok()` was
not covered by `option_map_or_err_ok` while it is by `manual_ok_or`, so
the category change may expose some new occurrences.
Without this check, the lint would suggest that
```rust
match test {
true if option == 5 => 10,
_ => 1,
};
```
is replaced by `if test { 10 } else { 1 }`.
changelog: [`match_bool`]: omit suggestion when guards are present in
`match` expression
Before edition 2024, some temporaries used in scrutinees of a `match`
used as the last expression of a block may outlive some referenced local
variables. Prevent those cases from happening by checking that alive
temporaries with significant drop do have a static lifetime.
The check is performed only for edition 2021 and earlier, and for the
last statement if it would become the last expression of the block.
changelog: [`unnecessary_semicolon`]: prevent borrow errors in editions
lower than 2024
r? @y21
Using `Vec::extend(std::iter::repeat_n(item, N))` allows to use the more
natural number of elements to add `N`, as is probably done in the
original loop, instead of computing the difference between the existing
number of elements and the wanted one.
Before MSRV 1.82, the older suggestion to use `Vec::resize()` is still
issued.
Inspired by #6156 (which predates `repeat_n()`).
changelog: [`same_item_push`]: recommend using `Vec::extend()` to extend
a vector
Before edition 2024, some temporaries used in scrutinees in a `match`
used as the last expression of a block may outlive some referenced
local variables. Prevent those cases from happening by checking that
alive temporaries with significant drop do have a static lifetime.
The check is performed only for edition 2021 and earlier, and for the
last statement if it would become the last expression of the block.
