src/test/ui/error-codes/E0225.stderr

error[E0225]: only auto traits can be used as additional traits in a trait object
  --> $DIR/E0225.rs:6:36
   |
LL |     let _: Box<dyn std::io::Read + std::io::Write>;
   |                    -------------   ^^^^^^^^^^^^^^
   |                    |               |
   |                    |               additional non-auto trait
   |                    |               trait alias used in trait object type (additional use)
   |                    first non-auto trait
   |                    trait alias used in trait object type (first use)

error[E0225]: only auto traits can be used as additional traits in a trait object
  --> $DIR/E0225.rs:8:20
   |
LL | trait Foo = std::io::Read + std::io::Write;
   |             -------------   -------------- additional non-auto trait
   |             |
   |             first non-auto trait
...
LL |     let _: Box<dyn Foo>;
   |                    ^^^
   |                    |
   |                    trait alias used in trait object type (additional use)
   |                    trait alias used in trait object type (first use)

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0225`.