error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
  --> $DIR/E0403.rs:1:11
   |
LL | fn foo<T, T>(s: T, u: T) {}
   |        -  ^ already used
   |        |
   |        first use of `T`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0403`.