error[E0308]: mismatched types
  --> $DIR/str-as-char.rs:7:19
   |
LL |     let _: &str = 'a';
   |            ----   ^^^ expected `&str`, found `char`
   |            |
   |            expected due to this
   |
help: if you meant to write a `str` literal, use double quotes
   |
LL |     let _: &str = "a";
   |                   ~~~

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.