error[E0275]: overflow evaluating the requirement `X>: NotAuto` --> $DIR/lifetime.rs:28:5 | LL | is_send::>>(); | ^^^^^^^^^^^^^^^^^^^^^^^^ | note: required for `Box>>` to implement `NotAuto` --> $DIR/lifetime.rs:18:18 | LL | impl NotAuto for Box {} | ^^^^^^^ ^^^^^^ = note: 3 redundant requirements hidden = note: required for `X>` to implement `NotAuto` note: required by a bound in `is_send` --> $DIR/lifetime.rs:22:15 | LL | fn is_send() {} | ^^^^^^^ required by this bound in `is_send` error: aborting due to previous error For more information about this error, try `rustc --explain E0275`.