error[E0277]: `NoSync` cannot be shared between threads safely --> $DIR/enum-negative-sync-impl.rs:20:19 | LL | requires_sync(container); | ------------- ^^^^^^^^^ `NoSync` cannot be shared between threads safely | | | required by a bound introduced by this call | help: within `Container`, the trait `Sync` is not implemented for `NoSync` --> $DIR/enum-negative-sync-impl.rs:9:1 | LL | struct NoSync; | ^^^^^^^^^^^^^ note: required because it appears within the type `Container` --> $DIR/enum-negative-sync-impl.rs:12:6 | LL | enum Container { | ^^^^^^^^^ note: required by a bound in `requires_sync` --> $DIR/enum-negative-sync-impl.rs:16:21 | LL | fn requires_sync(_: T) {} | ^^^^ required by this bound in `requires_sync` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.