error[E0277]: the type `str` cannot be indexed by `{integer}`
  --> $DIR/str-idx.rs:13:17
   |
LL |     let c: u8 = s[4]; //~ ERROR the type `str` cannot be indexed by `{integer}`
   |                 ^^^^ `str` cannot be indexed by `{integer}`
   |
   = help: the trait `std::ops::Index<{integer}>` is not implemented for `str`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.