rust/tests/ui/borrowck/borrowck-freeze-frozen-mut.rs
2024-02-16 20:02:50 +00:00

29 lines
637 B
Rust

//@ run-pass
// Test that a `&mut` inside of an `&` is freezable.
struct MutSlice<'a, T:'a> {
data: &'a mut [T]
}
fn get<'a, T>(ms: &'a MutSlice<'a, T>, index: usize) -> &'a T {
&ms.data[index]
}
pub fn main() {
let mut data = [1, 2, 3];
{
let slice = MutSlice { data: &mut data };
slice.data[0] += 4;
let index0 = get(&slice, 0);
let index1 = get(&slice, 1);
let index2 = get(&slice, 2);
assert_eq!(*index0, 5);
assert_eq!(*index1, 2);
assert_eq!(*index2, 3);
}
assert_eq!(data[0], 5);
assert_eq!(data[1], 2);
assert_eq!(data[2], 3);
}