Rollup merge of #62228 - varkor:must_use-trait-in-box, r=Centril

Extend the #[must_use] lint to boxed types

Fixes https://github.com/rust-lang/rust/issues/55506#issuecomment-506940181 (cc @Nemo157).

This should have been included as part of https://github.com/rust-lang/rust/pull/55663, but was overlooked.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/libstd/panicking.rs b/src/libstd/panicking.rs
index 9ef42063f94..797d85e941d 100644
--- a/src/libstd/panicking.rs
+++ b/src/libstd/panicking.rs
@@ -103,7 +103,9 @@ pub fn set_hook(hook: Box<dyn Fn(&PanicInfo<'_>) + 'static + Sync + Send>) {
         HOOK_LOCK.write_unlock();
 
         if let Hook::Custom(ptr) = old_hook {
-            Box::from_raw(ptr);
+            #[allow(unused_must_use)] {
+                Box::from_raw(ptr);
+            }
         }
     }
 }