Remove useless drop of copy type

Author: Urgau

core/src/task/poll.rs

@@ -116,7 +116,7 @@ impl<T> Poll<T> {
     ///     let fut = Pin::new(&mut fut);
     ///
     ///     let num = fut.poll(cx).ready()?;
-    ///     # drop(num);
+    ///     # let _ = num; // to silence unused warning
     ///     // ... use num
     ///
     ///     Poll::Ready(())

core/src/task/ready.rs

@@ -22,7 +22,7 @@ use core::task::Poll;
 ///     let fut = Pin::new(&mut fut);
 ///
 ///     let num = ready!(fut.poll(cx));
-///     # drop(num);
+///     # let _ = num;
 ///     // ... use num
 ///
 ///     Poll::Ready(())
@@ -44,7 +44,7 @@ use core::task::Poll;
 ///     Poll::Ready(t) => t,
 ///     Poll::Pending => return Poll::Pending,
 /// };
-///     # drop(num);
+///     # let _ = num; // to silence unused warning
 ///     # // ... use num
 ///     #
 ///     # Poll::Ready(())

std/src/panicking.rs

@@ -541,7 +541,7 @@ pub fn begin_panic_handler(info: &PanicInfo<'_>) -> ! {
             // Lazily, the first time this gets called, run the actual string formatting.
             self.string.get_or_insert_with(|| {
                 let mut s = String::new();
-                drop(s.write_fmt(*inner));
+                let _err = s.write_fmt(*inner);
                 s
             })
         }