45 lines
1.0 KiB
Rust
45 lines
1.0 KiB
Rust
//@ edition:2018
|
|
|
|
// Test that we get the expected borrow check errors when an async
|
|
// function (which takes multiple lifetimes) only returns data from
|
|
// one of them.
|
|
|
|
async fn multiple_named_lifetimes<'a, 'b>(a: &'a u8, _: &'b u8) -> &'a u8 {
|
|
a
|
|
}
|
|
|
|
// Both are borrowed whilst the future is live.
|
|
async fn future_live() {
|
|
let mut a = 22;
|
|
let mut b = 44;
|
|
let future = multiple_named_lifetimes(&a, &b);
|
|
a += 1; //~ ERROR cannot assign
|
|
b += 1; //~ ERROR cannot assign
|
|
let p = future.await;
|
|
drop(p);
|
|
}
|
|
|
|
// Just the return value is live after future is awaited.
|
|
async fn just_return_live() {
|
|
let mut a = 22;
|
|
let mut b = 44;
|
|
let future = multiple_named_lifetimes(&a, &b);
|
|
let p = future.await;
|
|
a += 1; //~ ERROR cannot assign
|
|
b += 1;
|
|
drop(p);
|
|
}
|
|
|
|
// Once `p` is dead, both `a` and `b` are unborrowed.
|
|
async fn after_both_dead() {
|
|
let mut a = 22;
|
|
let mut b = 44;
|
|
let future = multiple_named_lifetimes(&a, &b);
|
|
let p = future.await;
|
|
drop(p);
|
|
a += 1;
|
|
b += 1;
|
|
}
|
|
|
|
fn main() { }
|