1 error[E0282]: type annotations needed
2 --> $DIR/type-annotations-needed-expr.rs:2:39
4 LL | let _ = (vec![1,2,3]).into_iter().sum() as f64;
5 | ^^^ cannot infer type of the type parameter `S` declared on the associated function `sum`
7 help: consider specifying the generic argument
9 LL | let _ = (vec![1,2,3]).into_iter().sum::<S>() as f64;
12 error: aborting due to previous error
14 For more information about this error, try `rustc --explain E0282`.