Regression test for issue.
This commit is contained in:
parent
c83602a702
commit
1185798680
15
src/test/ui/issue-52126-assign-op-invariance.nll.stderr
Normal file
15
src/test/ui/issue-52126-assign-op-invariance.nll.stderr
Normal file
@ -0,0 +1,15 @@
|
||||
error[E0597]: `line` does not live long enough
|
||||
--> $DIR/issue-52126-assign-op-invariance.rs:44:28
|
||||
|
|
||||
LL | let v: Vec<&str> = line.split_whitespace().collect();
|
||||
| ^^^^ borrowed value does not live long enough
|
||||
LL | //~^ ERROR `line` does not live long enough
|
||||
LL | println!("accumulator before add_assign {:?}", acc.map);
|
||||
| ------- borrow later used here
|
||||
...
|
||||
LL | }
|
||||
| - borrowed value only lives until here
|
||||
|
||||
error: aborting due to previous error
|
||||
|
||||
For more information about this error, try `rustc --explain E0597`.
|
59
src/test/ui/issue-52126-assign-op-invariance.rs
Normal file
59
src/test/ui/issue-52126-assign-op-invariance.rs
Normal file
@ -0,0 +1,59 @@
|
||||
// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
|
||||
// file at the top-level directory of this distribution and at
|
||||
// http://rust-lang.org/COPYRIGHT.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
||||
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
||||
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
||||
// option. This file may not be copied, modified, or distributed
|
||||
// except according to those terms.
|
||||
|
||||
// Issue 52126: With respect to variance, the assign-op's like += were
|
||||
// accidentally lumped together with other binary op's. In both cases
|
||||
// we were coercing the LHS of the op to the expected supertype.
|
||||
//
|
||||
// The problem is that since the LHS of += is modified, we need the
|
||||
// parameter to be invariant with respect to the overall type, not
|
||||
// covariant.
|
||||
|
||||
use std::collections::HashMap;
|
||||
use std::ops::AddAssign;
|
||||
|
||||
pub fn main() {
|
||||
panics();
|
||||
}
|
||||
|
||||
pub struct Counter<'l> {
|
||||
map: HashMap<&'l str, usize>,
|
||||
}
|
||||
|
||||
impl<'l> AddAssign for Counter<'l>
|
||||
{
|
||||
fn add_assign(&mut self, rhs: Counter<'l>) {
|
||||
rhs.map.into_iter().for_each(|(key, val)| {
|
||||
let count = self.map.entry(key).or_insert(0);
|
||||
*count += val;
|
||||
});
|
||||
}
|
||||
}
|
||||
|
||||
/// often times crashes, if not prints invalid strings
|
||||
pub fn panics() {
|
||||
let mut acc = Counter{map: HashMap::new()};
|
||||
for line in vec!["123456789".to_string(), "12345678".to_string()] {
|
||||
let v: Vec<&str> = line.split_whitespace().collect();
|
||||
//~^ ERROR `line` does not live long enough
|
||||
println!("accumulator before add_assign {:?}", acc.map);
|
||||
let mut map = HashMap::new();
|
||||
for str_ref in v {
|
||||
let e = map.entry(str_ref);
|
||||
println!("entry: {:?}", e);
|
||||
let count = e.or_insert(0);
|
||||
*count += 1;
|
||||
}
|
||||
let cnt2 = Counter{map};
|
||||
acc += cnt2;
|
||||
println!("accumulator after add_assign {:?}", acc.map);
|
||||
// line gets dropped here but references are kept in acc.map
|
||||
}
|
||||
}
|
14
src/test/ui/issue-52126-assign-op-invariance.stderr
Normal file
14
src/test/ui/issue-52126-assign-op-invariance.stderr
Normal file
@ -0,0 +1,14 @@
|
||||
error[E0597]: `line` does not live long enough
|
||||
--> $DIR/issue-52126-assign-op-invariance.rs:44:28
|
||||
|
|
||||
LL | let v: Vec<&str> = line.split_whitespace().collect();
|
||||
| ^^^^ borrowed value does not live long enough
|
||||
...
|
||||
LL | }
|
||||
| - `line` dropped here while still borrowed
|
||||
LL | }
|
||||
| - borrowed value needs to live until here
|
||||
|
||||
error: aborting due to previous error
|
||||
|
||||
For more information about this error, try `rustc --explain E0597`.
|
Loading…
Reference in New Issue
Block a user