$ cargo run
   Compiling chapter10 v0.1.0 (file:///projects/chapter10)
error[E0515]: cannot return value referencing local variable `result`
  --> src/main.rs:11:5
   |
11 |     result.as_str()
   |     ------^^^^^^^^^
   |     |
   |     returns a value referencing data owned by the current function
   |     `result` is borrowed here

error: aborting due to previous error

For more information about this error, try `rustc --explain E0515`.
error: could not compile `chapter10`

To learn more, run the command again with --verbose.
