error[E0608]: cannot index into a value of type `({integer},)`
  --> $DIR/index_message.rs:3:14
   |
LL |     let _ = z[0];
   |              ^^^ help: to access tuple element `0`, use: `.0`
   |
   = help: tuples are indexed with a dot and a literal index: `tuple.0`, `tuple.1`, etc.

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0608`.