It would be relatively easy to overcome this limitation, but it would involve making slices "special" to the compiler, which also means another special rule for

It would be relatively easy to overcome this limitation, but it would involve making slices "special" to the compiler, which also means another special rule for the programmer to use. It would be preferable if you could make your own slice-like types which supported indexing, but to do that you need a mechanism to tell the compiler that your `IndexMut` implementation returns disjoint references for different indices, and that requires a mechanism for the compiler to determine whether two indices are the same (in case your indices are not integers).