warning: non-binding let on a type that implements `Drop`
  --> $DIR/let_underscore_drop.rs:13:5
   |
LL |     let _ = NontrivialDrop;
   |     ^^^^^^^^^^^^^^^^^^^^^^^
   |
note: the lint level is defined here
  --> $DIR/let_underscore_drop.rs:2:9
   |
LL | #![warn(let_underscore_drop)]
   |         ^^^^^^^^^^^^^^^^^^^
help: consider binding to an unused variable to avoid immediately dropping the value
   |
LL |     let _unused = NontrivialDrop;
   |         ~~~~~~~
help: consider immediately dropping the value
   |
LL |     drop(NontrivialDrop);
   |     ~~~~~              +

warning: 1 warning emitted