--- /dev/null
+error[E0308]: mismatched types
+ --> src/format.rs:51:5
+ |
+51 | ) -> Option<String> {
+ | -------------- expected `std::option::Option<std::string::String>` because of return type
+52 | / for ann in annotations {
+53 | | match (ann.range.0, ann.range.1) {
+54 | | (None, None) => continue,
+55 | | (Some(start), Some(end)) if start > end_index || end < start_index => continue,
+... |
+71 | | }
+72 | | }
+ | |_____^ expected enum `std::option::Option`, found ()
+ |