error[E0277]: the size for values of type `(dyn Fn() + 'static)` cannot be known at compilation time --> $DIR/issue-23281.rs:4:27 | LL | pub fn function(funs: Vec ()>) {} | ^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `(dyn Fn() + 'static)` note: required by a bound in `Vec` --> $DIR/issue-23281.rs:8:12 | LL | struct Vec { | ^ required by this bound in `Vec` help: you could relax the implicit `Sized` bound on `T` if it were used through indirection like `&T` or `Box` --> $DIR/issue-23281.rs:8:12 | LL | struct Vec { | ^ this could be changed to `T: ?Sized`... LL | t: T, | - ...if indirection were used here: `Box` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.