4 let mut x = vec![1usize];
5 x.last_mut().unwrap() = 2;
6 //~^ ERROR invalid left-hand side of assignment
7 x.last_mut().unwrap() += 1;
8 //~^ ERROR binary assignment operation `+=` cannot be applied to type `&mut usize`
10 let y = x.last_mut().unwrap();
12 //~^ ERROR mismatched types
14 //~^ ERROR binary assignment operation `+=` cannot be applied to type `&mut usize`