Update src/expressions/operator-expr.md

Co-authored-by: Niko Matsakis <[email protected]>

Author: joshlf

src/expressions/operator-expr.md

@@ -480,8 +480,7 @@ assert_eq!(values[1], 3);
 
 #### Slice DST pointer to pointer cast
 
-When `T` and `U` are both "slice DSTs" - i.e., slice types or types whose trailing field
-is a slice type - the raw pointer types `*const T`, `*mut T`, `*const U`, and `*mut U`
+For slice types like `[T]` and `[U]`, the raw pointer types `*const [T]`, `*mut [T]`, `*const [U]`, and `*mut [U]`
 encode the number of elements in this slice. Casts between these raw pointer types
 preserve the number of elements. Note that, as a consequence, such casts do *not*
 necessarily preserve the size of the pointer's referent (e.g., casting `*const [u16]`