question_mark suggestion changes code semantics #9518
Description
Summary
If let expression that produces a result is suggested to change to ?, changing the semantics of the code
Lint Name
question_mark
Reproducer
I tried this code:
fn do_stuff() -> Result<(), ()> {
let result = if let Err(e) = op1() { Err(e) } else { Ok(()) };
do_something_with_result(&result);
result
}
fn op1() -> Result<(), ()> {
Err(())
}
fn do_something_with_result(arg: &Result<(), ()>) {
println!("doing something with the result {arg:?}");
}
fn main() {
do_stuff().unwrap();
}
}I saw this happen:
warning: this block may be rewritten with the `?` operator
--> src/main.rs:2:18
|
2 | let result = if let Err(e) = op1() { Err(e) } else { Ok(()) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `op1()?`
|
= note: `#[warn(clippy::question_mark)]` on by default
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#question_mark
I expected to see this happen:
There should be no warning. Changing the code for what clippy suggests would prevent calling do_something_with_result when the result is an error
Version
rustc 1.64.0 (a55dd71d5 2022-09-19)
binary: rustc
commit-hash: a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52
commit-date: 2022-09-19
host: x86_64-unknown-linux-gnu
release: 1.64.0
LLVM version: 14.0.6
Additional Labels
No response