error[E0277]: the trait bound `String: Copy` is not satisfied --> $DIR/synthetic-hir-has-parent.rs:7:9 | LL | String: Copy; | ^^^^^^^^^^^^ the trait `Copy` is not implemented for `String` | = help: see issue #48214 help: add `#![feature(trivial_bounds)]` to the crate attributes to enable | LL + #![feature(trivial_bounds)] | error[E0277]: the trait bound `String: Copy` is not satisfied --> $DIR/synthetic-hir-has-parent.rs:4:18 | LL | fn demo() -> impl Foo | ^^^^^^^^ the trait `Copy` is not implemented for `String` | = help: see issue #48214 help: add `#![feature(trivial_bounds)]` to the crate attributes to enable | LL + #![feature(trivial_bounds)] | error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0277`.