[rustc.git] / src / test / ui / reassign-ref-mut.rs

// Tests how we behave when the user attempts to mutate an immutable
// binding that was introduced by either `ref` or `ref mut`
// patterns.
//
// Such bindings cannot be made mutable via the mere addition of the
// `mut` keyword, and thus we want to check that the compiler does not
// suggest doing so.

fn main() {
    let (mut one_two, mut three_four) = ((1, 2), (3, 4));
    let &mut (ref a, ref mut b) = &mut one_two;
    a = &three_four.0;
    //~^ ERROR cannot assign twice to immutable variable `a` [E0384]
    b = &mut three_four.1;
    //~^ ERROR cannot assign twice to immutable variable `b` [E0384]
}
Commit	Line	Data
94b46f34 XL	1	// Tests how we behave when the user attempts to mutate an immutable
	2	// binding that was introduced by either `ref` or `ref mut`
	3	// patterns.
	4	//
	5	// Such bindings cannot be made mutable via the mere addition of the
	6	// `mut` keyword, and thus we want to check that the compiler does not
	7	// suggest doing so.
	8
	9	fn main() {
	10	let (mut one_two, mut three_four) = ((1, 2), (3, 4));
	11	let &mut (ref a, ref mut b) = &mut one_two;
	12	a = &three_four.0;
	13	//~^ ERROR cannot assign twice to immutable variable `a` [E0384]
	14	b = &mut three_four.1;
	15	//~^ ERROR cannot assign twice to immutable variable `b` [E0384]
	16	}