error[E0277]: the size for values of type `str` cannot be known at compilation time --> $DIR/issue-41229-ref-str.rs:1:16 | LL | pub fn example(ref s: str) {} | ^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `str` = help: unsized fn params are gated as an unstable feature help: function arguments must have a statically known size, borrowed types always have a known size | LL | pub fn example(ref s: &str) {} | + error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.