mirror of
https://github.com/rust-lang/rust.git
synced 2025-11-04 23:15:28 +00:00
22f91aefd5
Remove unneeded lifetime bound from signature of BTreeSet::extract_if
One way to observe the difference between these signatures, using 0 explicit lifetimes and 0 contrived where-clauses:
```rust
use std::collections::btree_set::{BTreeSet, ExtractIf};
use std::ops::RangeFull;
fn repro(
set: &mut BTreeSet<i32>,
predicate: impl Fn(i32) -> bool,
) -> ExtractIf<i32, RangeFull, impl FnMut(&i32) -> bool> {
set.extract_if(.., move |x| predicate(*x))
}
```
**Before:**
```console
error[E0311]: the parameter type `impl Fn(i32) -> bool` may not live long enough
--> src/lib.rs:8:5
|
5 | set: &mut BTreeSet<i32>,
| ------------------ the parameter type `impl Fn(i32) -> bool` must be valid for the anonymous lifetime defined here...
...
8 | set.extract_if(.., move |x| predicate(*x))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `impl Fn(i32) -> bool` will meet its required lifetime bounds
|
help: consider adding an explicit lifetime bound
|
4 ~ fn repro<'a>(
5 ~ set: &'a mut BTreeSet<i32>,
6 ~ predicate: impl Fn(i32) -> bool + 'a,
7 ~ ) -> ExtractIf<'a, i32, RangeFull, impl FnMut(&i32) -> bool> {
|
```
**After:** compiles success.
- Tracking issue: https://github.com/rust-lang/rust/issues/70530