error[E0277]: `&'static (dyn Dummy + 'static)` cannot be sent between threads safely --> $DIR/kindck-send-object.rs:12:19 | LL | assert_send::<&'static (dyn Dummy + 'static)>(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&'static (dyn Dummy + 'static)` cannot be sent between threads safely | = help: the trait `Sync` is not implemented for `&'static (dyn Dummy + 'static)`, which is required by `&'static (dyn Dummy + 'static): Send` = note: required for `&'static (dyn Dummy + 'static)` to implement `Send` note: required by a bound in `assert_send` --> $DIR/kindck-send-object.rs:5:18 | LL | fn assert_send() { } | ^^^^ required by this bound in `assert_send` error[E0277]: `dyn Dummy` cannot be sent between threads safely --> $DIR/kindck-send-object.rs:17:19 | LL | assert_send::>(); | ^^^^^^^^^^^^^^ `dyn Dummy` cannot be sent between threads safely | = help: the trait `Send` is not implemented for `dyn Dummy`, which is required by `Box: Send` = note: required for `Unique` to implement `Send` note: required because it appears within the type `Box` --> $SRC_DIR/alloc/src/boxed.rs:LL:COL note: required by a bound in `assert_send` --> $DIR/kindck-send-object.rs:5:18 | LL | fn assert_send() { } | ^^^^ required by this bound in `assert_send` error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0277`.