may not => cannot

Author: compiler-errors

core/src/marker.rs

@@ -324,7 +324,7 @@ pub trait StructuralEq {
 /// attempt to derive a `Copy` implementation, we'll get an error:
 ///
 /// ```text
-/// the trait `Copy` may not be implemented for this type; field `points` does not implement `Copy`
+/// the trait `Copy` cannot be implemented for this type; field `points` does not implement `Copy`
 /// ```
 ///
 /// Shared references (`&T`) are also `Copy`, so a type can be `Copy`, even when it holds