Update URLs in Type Checking chapter
Updated links to `Adt`, `pat_ty` and `Tykind` in the "Type Checking" chapter of the book.
### Notes:
- For discussion about the whole project, please use the tracking issue for the project #10597 (It also contains a timeline, discussions, and more information).
changelog: Fix broken links in "Type Checking" chapter of the book
Add `MINIMAL_CFG_CONDITION` lint
I encountered a few cases where some code had:
```rust
#[cfg(any(unix))]
```
In this case, the `any` is useless. This lint checks this and also for the `all` condition.
```
changelog: [`unique_cfg_condition`]: Add new `UNIQUE_CFG_CONDITION` lint
```
Enhance `needless_collect`: lint in method/function arguments that take an `IntoIterator`
Updates `needless_collect` to also lint `collect` calls in method/function arguments that take an `IntoIterator` (for example `Extend::extend`). Every `Iterator` trivially implements `IntoIterator` and collecting it only causes an unnecessary allocation.
---
changelog: Enhancement: [`needless_collect`]: Now also detects function arguments, taking a generic `IntoIterator`
[#10777](https://github.com/rust-lang/rust-clippy/pull/10777)
<!-- changelog_checked -->
fixes#10762
`SpanlessEq` improvements
fixes#9775
Also includes a simplification to `consts::constant`'s interface since I was already touching the code.
At the start of `eq_expr` the check:
```rust
if !self.inner.allow_side_effects && left.span.ctxt() != right.span.ctxt() {
return false;
}
```
was removed. This was added in 49e2501 to handle `cfg` macros. This is better handled by the newly added `check_ctxt`.
changelog: [various lints]: Don't consider different `cfg!` expansions to be the same unless they are for the same config.
changelog: [various lints]: Don't consider the expansion of two different macros to be equal, even when they expand to the same token sequence.
changelog: [various lints]: Don't consider two blocks to be equal if they contain disabled code or empty macro expansions, unless those section contain the exact same token sequence.
* Don't consider expansions of different macros to be the same, even if they expand to the same tokens
* Don't consider `cfg!` expansions to be equal if they check different configs.
Rename `integer_arithmetic`
The lack of official feedback in #10200 made me give up on pursuing the matter but after yet another use-case that is not handled by `integer_arithmetic` (#10615), I think it is worth trying again.
---
changelog: Move/Deprecation: Rename `integer_arithmetic` to `arithmetic_side_effects`
[#10674](https://github.com/rust-lang/rust-clippy/pull/10674)
<!-- changelog_checked -->
don't remove `dbg!` in arbitrary expressions
Fixes#9914
The `dbg_macro` lint replaces empty `dbg!` invocations with the empty string in its suggestion, which is not always valid code in certain contexts (e.g. `let _ = dbg!();` becomes `let _ = ;`). This PR changes it to `()`, which should always be valid where `dbg!()` is valid (`dbg!()` with no arguments evaluates to `()`).
It also special-cases "standalone" `dbg!();` expression statements, where it will suggest removing the whole statement entirely like it did before.
changelog: [`dbg_macro`]: don't remove `dbg!()` in arbitrary expressions as it sometimes results in syntax errors
Remove unnecessary `clone` from `needless_collect` example
The example for [clippy::needless_collect](https://rust-lang.github.io/rust-clippy/master/#needless_collect) is written as follows:
```rust
let len = iterator.clone().collect::<Vec<_>>().len();
// should be
let len = iterator.count();
```
With this change, the unnecessary `clone()` is removed and the the standard
### Example
```rust
// original
```
Use instead:
```rust
// improved
```
structure is followed.
Discussion: https://github.com/rust-lang/rust-clippy/discussions/10784#discussion-5198885
changelog: [`needless_collect`]: Cleaned up the example in the lint documentation.
fix [`invalid_regex`] not recognizing new syntax introduced after regex-1.8.0
fixes: #10680
---
changelog: fix [`invalid_regex`] not recognizing new syntax introduced after regex-1.8.0
bump up `regex-syntax` dependency version to 0.7.0
Fix: Some suggestions generated by the option_if_let_else lint did not compile
This addresses a bug in Clippy where the fix suggestend by the `option_if_let_else` lint would not compile for `Result`s which have an impure expression in the `else` branch.
---
changelog: [`option_if_let_else`]: Fixed incorrect suggestion for `Result`s
[#10337](https://github.com/rust-lang/rust-clippy/pull/10337)
<!-- changelog_checked -->
Fixes#10335.
Updates `needless_collect` to lint for collecting into a method or
function argument thats taking an `IntoIterator` (for example `extend`).
Every `Iterator` trivially implements `IntoIterator` and colleting it
only causes an unnecessary allocation.
[arithmetic_side_effects] Consider referenced allowed or hard-coded types
Fix#10767
```
changelog: [`arithmetic_side_effects`]: Do not fire when dealing with allowed or hard-coded types that are referenced.
```
fix: warn on empty line outer AttrKind::DocComment
changelog: [`empty_line_after_doc_comments`]: add lint for checking empty lines after rustdoc comments.
Fixes: #10395
y21