Code
pub struct Foo<'a, 'b> {
pub ptr1: &'a str,
pub ptr2: &'b str,
}
pub struct Bar {}
// rustc suggests me that the return type should be `Foo<'_>`, but it should be `Foo<'_, '_>`
pub fn foo(_: &Bar) -> Foo {
todo!()
}Current output
warning: hiding a lifetime that's elided elsewhere is confusing
--> src/lib.rs:8:15
|
8 | pub fn foo(_: &Bar) -> Foo {
| ^^^^ ^^^
| | |
| | the same lifetime is hidden here
| | the same lifetime is hidden here
| the lifetime is elided here
|
= help: the same lifetime is referred to in inconsistent ways, making the signature confusing
= note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
help: use `'_` for type paths
|
8 | pub fn foo(_: &Bar) -> Foo<'_> {
| ++++
warning: `playground` (lib) generated 1 warning (run `cargo fix --lib -p playground` to apply 1 suggestion)
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.59s
Desired output
There are 2 lifetimes in Foo, so it has to be Foo<'_, '_>.
Rationale and extra context
Other cases
Rust Version
rustc 1.94.1 (e408947bf 2026-03-25)
binary: rustc
commit-hash: e408947bfd200af42db322daf0fadfe7e26d3bd1
commit-date: 2026-03-25
host: x86_64-unknown-linux-gnu
release: 1.94.1
LLVM version: 21.1.8
Anything else?
No response
Code
Current output
Desired output
There are 2 lifetimes in
Foo, so it has to beFoo<'_, '_>.Rationale and extra context
Other cases
Rust Version
Anything else?
No response