// run-pass // Assert that `mut self` on an immediate value doesn't // allow mutating the original - issue #10615. #[derive(Copy, Clone)] struct Value { n: isize } impl Value { fn squared(mut self) -> Value { self.n *= self.n; self } } pub fn main() { let x = Value { n: 3 }; let y = x.squared(); assert_eq!(x.n, 3); assert_eq!(y.n, 9); }