error[E0277]: the size for values of type `[i32]` cannot be known at compilation time --> $DIR/issue-20433.rs:6:5 | LL | fn iceman(c: Vec<[i32]>) {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time | = help: the trait `std::marker::Sized` is not implemented for `[i32]` = note: to learn more, visit = note: required by `std::vec::Vec` error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.