Closed
Description
Summary
Taken from this real-world example: https://github.com/rust-lang/log/blob/7fb28c36c7a418912612ab37ab49bd4ca1a3a7f5/src/lib.rs#L812-L826
Lint Name
match_same_arms
Reproducer
I tried this code:
#![warn(clippy::match_same_arms)]
pub enum MaybeStaticStr<'a> {
Static(&'static str),
Borrowed(&'a str),
}
impl<'a> MaybeStaticStr<'a> {
pub fn get(&self) -> &'a str {
match *self {
MaybeStaticStr::Static(s) => s,
MaybeStaticStr::Borrowed(s) => s,
}
}
}I saw this happen:
warning: this match arm has an identical body to another arm
--> src/lib.rs:12:13
|
12 | MaybeStaticStr::Borrowed(s) => s,
| ---------------------------^^^^^
| |
| help: try merging the arm patterns: `MaybeStaticStr::Borrowed(s) | MaybeStaticStr::Static(s)`
|
note: the lint level is defined here
--> src/lib.rs:1:9
|
1 | #![warn(clippy::match_same_arms)]
| ^^^^^^^^^^^^^^^^^^^^^^^
= help: or try changing either arm body
note: other arm here
--> src/lib.rs:11:13
|
11 | MaybeStaticStr::Static(s) => s,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_same_arms
Problem is, that if I do that:
error[[E0495]](https://doc.rust-lang.org/stable/error-index.html#E0495): cannot infer an appropriate lifetime due to conflicting requirements
--> src/lib.rs:10:15
|
10 | match *self {
| ^^^^^
|
note: first, the lifetime cannot outlive the lifetime `'a` as defined here...
--> src/lib.rs:8:6
|
8 | impl<'a> MaybeStaticStr<'a> {
| ^^
note: ...so that the types are compatible
--> src/lib.rs:10:15
|
10 | match *self {
| ^^^^^
= note: expected `MaybeStaticStr<'_>`
found `MaybeStaticStr<'a>`
= note: but, the lifetime must be valid for the static lifetime...
note: ...so that the types are compatible
--> src/lib.rs:12:38
|
12 | MaybeStaticStr::Borrowed(s) => s,
| ^
= note: expected `&'static str`
found `&str`
Version
rustc 1.63.0-nightly (28b891916 2022-05-29)
binary: rustc
commit-hash: 28b891916d4c85cd10fb2e9cfa8bc836a2c459f3
commit-date: 2022-05-29
host: x86_64-unknown-linux-gnu
release: 1.63.0-nightly
LLVM version: 14.0.4
Additional Labels
@rustbot label +I-suggestion-causes-error