Address issue #99265 by checking each positionally used argument
to see if the argument is named and adding a lint to use the name
instead. This way, when named arguments are used positionally in a
different order than their argument order, the suggested lint is
correct.
For example:
```
println!("{b} {}", a=1, b=2);
```
This will now generate the suggestion:
```
println!("{b} {a}", a=1, b=2);
```
Additionally, this check now also correctly replaces or inserts
only where the positional argument is (or would be if implicit).
Also, width and precision are replaced with their argument names
when they exists.
Since the issues were so closely related, this fix for issue #99265
also fixes issue #99266.
Fixes#99265Fixes#99266
Add new lint `obfuscated_if_else`
part of #9100, additional commits could make it work with `then` and `unwrap_or_else` as well
changelog: Add new lint `obfuscated_if_else`
unused_self: respect avoid-breaking-exported-api
```
changelog: [`unused_self`]: Now respects the `avoid-breaking-exported-api` config option
```
Fixes#9195.
I mostly copied the implementation from `unnecessary_wraps`, since I don't have much understanding of rustc internals.
[`box_collection`]: raise warn for all std collections
So far, only [`Vec`, `String`, `HashMap`] were considered.
Extend collection checklist for this lint with:
- `HashSet`
- `VecDeque`
- `LinkedList`
- `BTreeMap`
- `BTreeSet`
- `BinaryHeap`
changelog: [`box_collection`]: raise warn for all std collections
Move format_push_string to restriction
Fixes#9077 (kinda) by moving the lint to the restriction group. As I noted in that issue, I think the suggested change is too much and as the OP of the issue points out, the ramifications of the change are not necessarily easily understood. As such I don't think the lint should be enabled by default.
changelog: [`format_push_string`]: moved to restriction (see #9077).
Implement `for<>` lifetime binder for closures
This PR implements RFC 3216 ([TI](https://github.com/rust-lang/rust/issues/97362)) and allows code like the following:
```rust
let _f = for<'a, 'b> |a: &'a A, b: &'b B| -> &'b C { b.c(a) };
// ^^^^^^^^^^^--- new!
```
cc ``@Aaron1011`` ``@cjgillot``
Always create elided lifetime parameters for functions
Anonymous and elided lifetimes in functions are sometimes (async fns) --and sometimes not (regular fns)-- desugared to implicit generic parameters.
This difference of treatment makes it some downstream analyses more complicated to handle. This step is a pre-requisite to perform lifetime elision resolution on AST.
There is currently an inconsistency in the treatment of argument-position impl-trait for functions and async fns:
```rust
trait Foo<'a> {}
fn foo(t: impl Foo<'_>) {} //~ ERROR missing lifetime specifier
async fn async_foo(t: impl Foo<'_>) {} //~ OK
fn bar(t: impl Iterator<Item = &'_ u8>) {} //~ ERROR missing lifetime specifier
async fn async_bar(t: impl Iterator<Item = &'_ u8>) {} //~ OK
```
The current implementation reports "missing lifetime specifier" on `foo`, but **accepts it** in `async_foo`.
This PR **proposes to accept** the anonymous lifetime in both cases as an extra generic lifetime parameter.
This change would be insta-stable, so let's ping t-lang.
Anonymous lifetimes in GAT bindings keep being forbidden:
```rust
fn foo(t: impl Foo<Assoc<'_> = Bar<'_>>) {}
^^ ^^
forbidden ok
```
I started a discussion here: https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Anonymous.20lifetimes.20in.20universal.20impl-trait/near/284968606
r? ``@petrochenkov``
