error: non-binding `let` on a synchronization lock
  --> $DIR/let_underscore_lock.rs:10:5
   |
LL |     let _ = p_m.lock();
   |     ^^^^^^^^^^^^^^^^^^^
   |
   = help: consider using an underscore-prefixed named binding or dropping explicitly with `std::mem::drop`
   = note: `-D clippy::let-underscore-lock` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::let_underscore_lock)]`

error: non-binding `let` on a synchronization lock
  --> $DIR/let_underscore_lock.rs:14:5
   |
LL |     let _ = p_m1.lock();
   |     ^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider using an underscore-prefixed named binding or dropping explicitly with `std::mem::drop`

error: non-binding `let` on a synchronization lock
  --> $DIR/let_underscore_lock.rs:18:5
   |
LL |     let _ = p_rw.read();
   |     ^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider using an underscore-prefixed named binding or dropping explicitly with `std::mem::drop`

error: non-binding `let` on a synchronization lock
  --> $DIR/let_underscore_lock.rs:20:5
   |
LL |     let _ = p_rw.write();
   |     ^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider using an underscore-prefixed named binding or dropping explicitly with `std::mem::drop`

error: aborting due to 4 previous errors