error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
  --> $DIR/duplicate-type-parameter.rs:1:12
   |
LL | type Foo<T,T> = Option<T>;
   |          - ^ already used
   |          |
   |          first use of `T`

error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
  --> $DIR/duplicate-type-parameter.rs:4:14
   |
LL | struct Bar<T,T>(T);
   |            - ^ already used
   |            |
   |            first use of `T`

error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
  --> $DIR/duplicate-type-parameter.rs:7:14
   |
LL | struct Baz<T,T> {
   |            - ^ already used
   |            |
   |            first use of `T`

error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
  --> $DIR/duplicate-type-parameter.rs:12:12
   |
LL | enum Boo<T,T> {
   |          - ^ already used
   |          |
   |          first use of `T`

error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
  --> $DIR/duplicate-type-parameter.rs:18:11
   |
LL | fn quux<T,T>(x: T) {}
   |         - ^ already used
   |         |
   |         first use of `T`

error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
  --> $DIR/duplicate-type-parameter.rs:21:13
   |
LL | trait Qux<T,T> {}
   |           - ^ already used
   |           |
   |           first use of `T`

error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
  --> $DIR/duplicate-type-parameter.rs:24:8
   |
LL | impl<T,T> Qux<T,T> for Option<T> {}
   |      - ^ already used
   |      |
   |      first use of `T`

error[E0207]: the type parameter `T` is not constrained by the impl trait, self type, or predicates
  --> $DIR/duplicate-type-parameter.rs:24:6
   |
LL | impl<T,T> Qux<T,T> for Option<T> {}
   |      ^ unconstrained type parameter

error: aborting due to 8 previous errors

Some errors have detailed explanations: E0207, E0403.
For more information about an error, try `rustc --explain E0207`.