rust/tests/ui/nll/drop-no-may-dangle.rs
2023-01-11 09:32:08 +00:00

31 lines
786 B
Rust

// Basic test for liveness constraints: the region (`R1`) that appears
// in the type of `p` must include everything until `p` is dropped
// because of destructor. (Note that the stderr also identifies this
// destructor in the error message.)
#![allow(warnings)]
#![feature(dropck_eyepatch)]
fn use_x(_: usize) -> bool { true }
fn main() {
let mut v = [1, 2, 3];
let p: WrapMayNotDangle<&usize> = WrapMayNotDangle { value: &v[0] };
if true {
use_x(*p.value);
} else {
use_x(22);
v[0] += 1; //~ ERROR cannot assign to `v[_]` because it is borrowed
}
v[0] += 1; //~ ERROR cannot assign to `v[_]` because it is borrowed
}
struct WrapMayNotDangle<T> {
value: T
}
impl<T> Drop for WrapMayNotDangle<T> {
fn drop(&mut self) { }
}