error[E0225]: only auto traits can be used as additional traits in a trait object
  --> $DIR/issue-22560.rs:9:23
   |
LL | type Test = dyn Add + Sub;
   |                 ---   ^^^ additional non-auto trait
   |                 |
   |                 first non-auto trait
   |
   = help: consider creating a new trait with all of these as supertraits and using that trait here instead: `trait NewTrait: Add + Sub {}`
   = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>

error[E0191]: the value of the associated types `Output` (from trait `Add`), `Output` (from trait `Sub`) must be specified
  --> $DIR/issue-22560.rs:9:17
   |
LL |     type Output;
   |     ----------- `Output` defined here
...
LL |     type Output;
   |     ----------- `Output` defined here
...
LL | type Test = dyn Add + Sub;
   |                 ^^^   ^^^ associated type `Output` must be specified
   |                 |
   |                 associated type `Output` must be specified
   |
help: specify the associated types
   |
LL | type Test = dyn Add<Output = Type> + Sub<Output = Type>;
   |                 ~~~~~~~~~~~~~~~~~~   ~~~~~~~~~~~~~~~~~~

error[E0393]: the type parameter `Rhs` must be explicitly specified
  --> $DIR/issue-22560.rs:9:17
   |
LL | trait Add<Rhs=Self> {
   | ------------------- type parameter `Rhs` must be specified for this
...
LL | type Test = dyn Add + Sub;
   |                 ^^^ help: set the type parameter to the desired type: `Add<Rhs>`
   |
   = note: because of the default `Self` reference, type parameters must be specified on object types

error[E0393]: the type parameter `Rhs` must be explicitly specified
  --> $DIR/issue-22560.rs:9:23
   |
LL | trait Sub<Rhs=Self> {
   | ------------------- type parameter `Rhs` must be specified for this
...
LL | type Test = dyn Add + Sub;
   |                       ^^^ help: set the type parameter to the desired type: `Sub<Rhs>`
   |
   = note: because of the default `Self` reference, type parameters must be specified on object types

error: aborting due to 4 previous errors

Some errors have detailed explanations: E0191, E0225, E0393.
For more information about an error, try `rustc --explain E0191`.