I think he was referring to areas of contiguous memory (arrays) where the size of the area is separated from the pointer to that area. Nearly any operation on t

I think he was referring to areas of contiguous memory (arrays) where the size of the area is separated from the pointer to that area. Nearly any operation on the array will require both pieces of information, and tons of C bugs come from making assumptions about the length of an array that aren't true. So, better just to carry the length along with the pointer (Rust calls these "fat" pointers) and use that as the source of truth about the array length (for dynamically sized arrays, such as those created by malloc).