error: `?Trait` is not permitted in trait object types --> $DIR/trait-object-trait-parens.rs:6:25 | LL | let _: Box<(Copy) + (?Sized) + (for<'a> Trait<'a>)>; | ^^^^^^^^ error: `?Trait` is not permitted in trait object types --> $DIR/trait-object-trait-parens.rs:11:47 | LL | let _: Box<(for<'a> Trait<'a>) + (Copy) + (?Sized)>; | ^^^^^^^^ warning: trait objects without an explicit `dyn` are deprecated --> $DIR/trait-object-trait-parens.rs:6:16 | LL | let _: Box<(Copy) + (?Sized) + (for<'a> Trait<'a>)>; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn (Copy) + (?Sized) + (for<'a> Trait<'a>)` | = note: #[warn(bare_trait_objects)] on by default warning: trait objects without an explicit `dyn` are deprecated --> $DIR/trait-object-trait-parens.rs:9:16 | LL | let _: Box<(?Sized) + (for<'a> Trait<'a>) + (Copy)>; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn (?Sized) + (for<'a> Trait<'a>) + (Copy)` warning: trait objects without an explicit `dyn` are deprecated --> $DIR/trait-object-trait-parens.rs:11:16 | LL | let _: Box<(for<'a> Trait<'a>) + (Copy) + (?Sized)>; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn (for<'a> Trait<'a>) + (Copy) + (?Sized)` error[E0261]: use of undeclared lifetime name `'a` --> $DIR/trait-object-trait-parens.rs:11:31 | LL | let _: Box<(for<'a> Trait<'a>) + (Copy) + (?Sized)>; | ^^ undeclared lifetime error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0261`.