error: returning the result of a let binding from a block
  --> $DIR/matches.rs:9:13
   |
LL |             let x = 3;
   |             ---------- unnecessary let binding
LL |             x
   |             ^
   |
   = note: `-D clippy::let-and-return` implied by `-D warnings`
help: return the expression directly
   |
LL |             
LL |             3
   |

error: aborting due to previous error