Latest nightly report

[amircodota]

Summary

warning: this `let...else` may be rewritten with the `?` operator --> cloud2/snippet_suggestions/src/snippet_prompt/mod.rs:229:9 | 229 | / let Some(enricher_args): Option<EnricherArgs> = args.into() else { 230 | | return None; 231 | | }; | |__________^ help: replace it with: `let enricher_args = args.into()?;` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#question_mark = note: `#[warn(clippy::question_mark)]` on by default

This does not work because the From impl does not match

args is of type args: &SnippetAutocompleteRequest,

This is the From impl

impl<'a> From<&'a SnippetAutocompleteRequest<'a>> for Option<EnricherArgs<'a>> {

Lint Name

clippy::question_mark

Reproducer

No response

Version

cargo +nightly --version                                                                                                                          cargo 1.77.0-nightly (ac6bbb332 2023-12-26)

Additional Labels

No response

[PartiallyUntyped]

@rustbot label T-middle -E-needs-mcve

[PartiallyUntyped]

Hi, if you don't mind, could you provide a minimal example?

[amircodota]

Hi

Here's a simple main.rs

fn main() {
    _ = my_func();
}

fn my_func() -> Option<MyStruct2> {
    let Some(my): Option<MyStruct2> = MyStruct.into() else { return None };

    my.do_something();

    Some(my)
}

struct MyStruct;
struct MyStruct2;

impl MyStruct2 {
    fn do_something(&self) {
        println!("do something");
    }

}

impl From<MyStruct> for Option<MyStruct2> {
    fn from(_: MyStruct) -> Self {
        Some(MyStruct2)
    }
}

If I run cargo clippy it warns me that

warning: this `let...else` may be rewritten with the `?` operator
 --> src/main.rs:6:5
  |
6 |     let Some(my): Option<MyStruct2> = MyStruct.into() else { return None };
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `let my = MyStruct.into()?;`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#question_mark
  = note: `#[warn(clippy::question_mark)]` on by default

However, if I change the line in question to

let my: MyStruct2 = MyStruct.into()?;

it does not compile

error[E0283]: type annotations needed
 --> src/main.rs:6:34
  |
6 |     let my: MyStruct2 = MyStruct.into()?;
  |                                  ^^^^
  |
  = note: cannot satisfy `_: From<MyStruct>`
  = note: required for `MyStruct` to implement `Into<_>`
help: try using a fully qualified path to specify the expected types
  |
6 |     let my: MyStruct2 = <MyStruct as Into<T>>::into(MyStruct)?;
  |                         ++++++++++++++++++++++++++++        ~

For more information about this error, try `rustc --explain E0283`.

NOTE:
In this simple case, clippy warns me even in the latest stable (rust 1.75). However, in my (more complex) real code, clippy does not warn, however, clippy nightly does warn.