error[E0282]: type annotations needed for `[_; 3]` --> $DIR/slice-patterns-irrefutable.rs:43:9 | LL | let b; | ^ LL | LL | [a, b] = Default::default(); | - type must be known at this point | help: consider giving `b` an explicit type, where the placeholders `_` are specified | LL | let b: [_; 3]; | ++++++++ error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0282`.