This removes the empty separate files for the different groups and adds
a single file giving short explanations for each group and what to
expect from those groups.
The UI tests now use the latest edition by default. Testing on older
editions should almost never be necessary, so I don't see a need to
document this.
This reformats all the internal docs, so that the md files use at most
80 characters per line. This is the usual formatting of md files. We
allow 120 chars per line in CI though.
Add new lint [`needless_parens_on_range_literals`]
changelog: Adds a new lint [`needless_parens_on_range_literals`] to warn on needless braces on literals in a range statement
For example, the lint would catch
```log
error: needless parenthesis on range literals can be removed
--> $DIR/needless_parens_on_range_literals.rs:8:13
|
LL | let _ = ('a')..=('z');
| ^^^^^ help: try: `'a'`
|
= note: `-D clippy::needless-parens-on-range-literals` implied by `-D warnings`
```
improve [`for_loops_over_fallibles`] to detect the usage of iter, iter_mut and into_iterator
fix#6762
detects code like
```rust
for _ in option.iter() {
//..
}
```
changelog: Improve [`for_loops_over_fallibles`] to detect `for _ in option.iter() {}` or using `iter_mut()` or `into_iterator()`.
Remove the unneeded wrapping and unwrapping in suggestion creation.
Collecting to Option<Vec<_>> only returns None if one of the elements is
None and that is never the case here.
fix(manual_find_map and manual_filter_map): check clone method
close#8920
Added conditional branching when the clone method is used.
Thank you in advance.
---
changelog: check `clone()` and other variant preserving methods in [`manual_find_map`] and [`manual_filter_map`]
add [`as_underscore`] lint
closes#8847
detect usage of `as _` and enforce the usage of explicit type like
```rust
fn foo(n: usize) {}
let n: u16 = 256;
foo(n as _);
```
will suggest to change to
```rust
fn foo(n: usize) {}
let n: u16 = 256;
foo(n as usize);
```
changelog: add [`as_underscore`] lint
