mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-01 11:13:43 +00:00
22 lines
578 B
Rust
22 lines
578 B
Rust
//@ run-pass
|
|
|
|
#![warn(unused_assignments)]
|
|
|
|
fn main() {
|
|
let mut a;
|
|
// Assignment occurs left-to-right.
|
|
// However, we emit warnings when this happens, so it is clear that this is happening.
|
|
(a, a) = (0, 1); //~ WARN value assigned to `a` is never read
|
|
assert_eq!(a, 1);
|
|
|
|
// We can't always tell when a variable is being assigned to twice, which is why we don't try
|
|
// to emit an error, which would be fallible.
|
|
let mut x = 1;
|
|
(*foo(&mut x), *foo(&mut x)) = (5, 6);
|
|
assert_eq!(x, 6);
|
|
}
|
|
|
|
fn foo<'a>(x: &'a mut u32) -> &'a mut u32 {
|
|
x
|
|
}
|