1 error[E0415]: identifier `a` is bound more than once in this parameter list
2 --> $DIR/duplicate-parameter.rs:1:16
4 LL | fn f(a: isize, a: isize) {}
5 | ^ used as parameter more than once
7 error: aborting due to previous error
9 For more information about this error, try `rustc --explain E0415`.