error: non-binding `let` on a future
  --> tests/ui/let_underscore_future.rs:14:5
   |
LL |     let _ = some_async_fn();
   |     ^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider awaiting the future or dropping explicitly with `std::mem::drop`
   = note: `-D clippy::let-underscore-future` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::let_underscore_future)]`

error: non-binding `let` on a future
  --> tests/ui/let_underscore_future.rs:16:5
   |
LL |     let _ = custom();
   |     ^^^^^^^^^^^^^^^^^
   |
   = help: consider awaiting the future or dropping explicitly with `std::mem::drop`

error: non-binding `let` on a future
  --> tests/ui/let_underscore_future.rs:21:5
   |
LL |     let _ = future;
   |     ^^^^^^^^^^^^^^^
   |
   = help: consider awaiting the future or dropping explicitly with `std::mem::drop`

error: aborting due to 3 previous errors