compiler/rustc_error_codes/src/error_codes/E0608.md

   1 An attempt to use index on a type which doesn't implement the `std::ops::Index`
   2 trait was performed.
   3
   4 Erroneous code example:
   5
   6 ```compile_fail,E0608
   7 0u8[2]; // error: cannot index into a value of type `u8`
   8 ```
   9
  10 To be able to index into a type it needs to implement the `std::ops::Index`
  11 trait. Example:
  12
  13 ```
  14 let v: Vec<u8> = vec![0, 1, 2, 3];
  15
  16 // The `Vec` type implements the `Index` trait so you can do:
  17 println!("{}", v[2]);
  18 ```