match_single_binding can't add semicolon if expression is returned #15537
Description
Using the following flags
--force-warn clippy::match_single_binding
this code:
struct A;
struct B;
impl Drop for A {
fn drop(&mut self) {}
}
impl Drop for B {
fn drop(&mut self) {}
}
#[inline(always)]
fn no_unwind() {}
fn weird_temporary(a: A, b: B, nothing: ((), (), ()), x: bool) -> ((), (), ()) {
'scope: {
(
{
let _z = b;
if x {
break 'scope nothing;
}
},
match { a } {
_ => (),
},
no_unwind(),
)
}
}
fn main() {}caused the following diagnostics:
Checking _104736 v0.1.0 (/tmp/icemaker_global_tempdir.Cuu53SxwZ7v9/icemaker_clippyfix_tempdir.IWeaSbA3kdqa/_104736)
warning: this match could be replaced by its scrutinee and body
--> src/main.rs:23:13
|
23 | / match { a } {
24 | | _ => (),
25 | | },
| |_____________^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_single_binding
= note: requested on the command line with `--force-warn clippy::match-single-binding`
help: consider using the scrutinee and body instead
|
23 ~ { a };
24 ~ (),
|
warning: `_104736` (bin "_104736") generated 1 warning
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.30s
However after applying these diagnostics, the resulting code:
struct A;
struct B;
impl Drop for A {
fn drop(&mut self) {}
}
impl Drop for B {
fn drop(&mut self) {}
}
#[inline(always)]
fn no_unwind() {}
fn weird_temporary(a: A, b: B, nothing: ((), (), ()), x: bool) -> ((), (), ()) {
'scope: {
(
{
let _z = b;
if x {
break 'scope nothing;
}
},
{ a },;
(),
no_unwind(),
)
}
}
fn main() {}no longer compiled:
Checking _104736 v0.1.0 (/tmp/icemaker_global_tempdir.Cuu53SxwZ7v9/icemaker_clippyfix_tempdir.IWeaSbA3kdqa/_104736)
error: expected expression, found `;`
--> src/main.rs:23:19
|
23 | { a },;
| ^ expected expression
error: could not compile `_104736` (bin "_104736" test) due to 1 previous error
warning: build failed, waiting for other jobs to finish...
error: could not compile `_104736` (bin "_104736") due to 1 previous error
Version:
rustc 1.91.0-nightly (d20509c2a 2025-08-22)
binary: rustc
commit-hash: d20509c2a0c71b60aa2b51566e4d14920e8a1661
commit-date: 2025-08-22
host: x86_64-unknown-linux-gnu
release: 1.91.0-nightly
LLVM version: 21.1.0