Rollup merge of #111659 - y21:suggest-as-deref, r=cjgillot

suggest `Option::as_deref(_mut)` on type mismatch in option combinator if it passes typeck

Fixes #106342.
This adds a suggestion to call `.as_deref()` (or `.as_deref_mut()` resp.) if typeck fails due to a type mismatch in the function passed to an `Option` combinator such as `.map()` or `.and_then()`.
For example:
```rs
fn foo(_: &str) {}
Some(String::new()).map(foo);
```
The `.map()` method requires its argument to satisfy `F: FnOnce(String)`, but it received `fn(&str)`, which won't pass. However, placing a `.as_deref()` before the `.map()` call fixes this since `&str == &<String as Deref>::Target`

0 files changed, 0 insertions, 0 deletions