1 You gave an unnecessary type or const parameter in a type alias. Erroneous
5 type Foo<T> = u32; // error: type parameter `T` is unused
7 type Foo<A,B> = Box<A>; // error: type parameter `B` is unused
10 Please check you didn't write too many parameters. Example:
13 type Foo = u32; // ok!
14 type Foo2<A> = Box<A>; // ok!