1 error[E0282]: type annotations needed
2 --> $DIR/fn-needing-specified-return-type-param.rs:3:13
5 | ^ cannot infer type of the type parameter `A` declared on the function `f`
7 help: consider specifying the generic argument
12 error: aborting due to previous error
14 For more information about this error, try `rustc --explain E0282`.