#[derive(Clone, Copy)] | |
struct S { | |
a: u8, | |
b: u16, | |
} | |
#[derive(Clone, Copy)] | |
union U { | |
s: S, | |
c: u32, | |
} | |
fn main() { | |
unsafe { | |
{ | |
let mut u = U { s: S { a: 0, b: 1 } }; | |
let ra = &mut u.s.a; | |
let b = u.s.b; // OK | |
ra.use_mut(); | |
} | |
{ | |
let mut u = U { s: S { a: 0, b: 1 } }; | |
let ra = &mut u.s.a; | |
let b = u.c; //~ ERROR cannot use `u.c` because it was mutably borrowed | |
ra.use_mut(); | |
} | |
} | |
} | |
trait Fake { fn use_mut(&mut self) { } fn use_ref(&self) { } } | |
impl<T> Fake for T { } |