Couldn't syntax like `a_string[..3]` be made to result in compilation errors in Rust? Since that'd almost always be a bug? (right?) And in the rare cases, when

Couldn't syntax like `a_string[..3]` be made to result in compilation errors in Rust? Since that'd almost always be a bug? (right?) And in the rare cases, when it's not a bug, then one can just use `as_bytes` which would be good to do in any case, to indicate to other humans that this is not a bug. B.t.w. I love the error message `[..3]` generates: "thread 'main' panicked at 'byte index 3 is not a char boundary; it is inside '早' (bytes 2..5) of `ab早`'" — I've never seen such easy to understand error messages in any language (except for in a few cases in Scala).