FP in clippy::if_then_some_else_none with short-circuiting ? at sole expression #15770
Description
Summary
This seems like a continuation of #11394, but the case is even simpler with ? at the tail expression.
Lint Name
if_then_some_else_none
Reproducer
I tried this code playground link:
#![warn(clippy::if_then_some_else_none)]
fn maybe_error() -> Result<u32, &'static str>
{
Err("error!")
}
pub fn trying(b: bool) -> Result<(), &'static str>
{
let _x: Option<u32> = if b {
Some(maybe_error()?)
} else {
None
};
// Process _x locally
Ok(())
}Clippy generated an invalid suggestion:
warning: this could be simplified with `bool::then`
--> src/lib.rs:10:26
|
10 | let _: Option<u32> = if b {
| __________________________^
11 | | Some(maybe_error()?)
12 | | } else {
13 | | None
14 | | };
| |_____^ help: try: `b.then(|| maybe_error()?)`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_then_some_else_none
note: the lint level is defined here
--> src/lib.rs:1:9
|
1 | #![warn(clippy::if_then_some_else_none)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
resulting in a compilation error:
Checking playground v0.0.1 (/playground)
error[E0277]: the `?` operator can only be used in a closure that returns `Result` or `Option` (or another type that implements `std::ops::FromResidual`)
--> src/lib.rs:40:49
|
40 | let _: Option<u32> = b.then(|| maybe_error()?);
| -- ^ cannot use the `?` operator in a closure that returns `u32`
| |
| this function should return `Result` or `Option` to accept `?`
For more information about this error, try `rustc --explain E0277`.
error: could not compile `playground` (lib) due to 1 previous error
Version
Same effect with playground versions:
Stable channel
Build using the Stable version: 1.90.0
Beta channel
Build using the Beta version: 1.91.0-beta.3
(2025-09-20 bb624dcb4c8ab987e10c)
Nightly channel
Build using the Nightly version: 1.92.0-nightly
(2025-09-26 54a8a1db604e4caff93e)