1 files changed, 16 insertions, 92 deletions

diff --git a/src/libcore/mem.rs b/src/libcore/mem.rs
index a0fe6e98806..1a54f03bb00 100644
--- a/src/libcore/mem.rs
+++ b/src/libcore/mem.rs
@@ -918,7 +918,6 @@ pub fn discriminant<T>(v: &T) -> Discriminant<T> {
     }
 }
 
-
 /// A wrapper to inhibit compiler from automatically calling `T`’s destructor.
 ///
 /// This wrapper is 0-cost.
@@ -954,11 +953,18 @@ pub fn discriminant<T>(v: &T) -> Discriminant<T> {
 ///     }
 /// }
 /// ```
+#[cfg(not(stage0))]
 #[stable(feature = "manually_drop", since = "1.20.0")]
-#[allow(unions_with_drop_fields)]
-#[derive(Copy)]
-pub union ManuallyDrop<T>{ value: T }
+#[lang = "manually_drop"]
+#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct ManuallyDrop<T> {
+    value: T,
+}
+
+#[cfg(stage0)]
+include!("manually_drop_stage0.rs");
 
+#[cfg(not(stage0))]
 impl<T> ManuallyDrop<T> {
     /// Wrap a value to be manually dropped.
     ///
@@ -972,7 +978,7 @@ impl<T> ManuallyDrop<T> {
     #[rustc_const_unstable(feature = "const_manually_drop_new")]
     #[inline]
     pub const fn new(value: T) -> ManuallyDrop<T> {
-        ManuallyDrop { value: value }
+        ManuallyDrop { value }
     }
 
     /// Extract the value from the ManuallyDrop container.
@@ -987,9 +993,7 @@ impl<T> ManuallyDrop<T> {
     #[stable(feature = "manually_drop", since = "1.20.0")]
     #[inline]
     pub fn into_inner(slot: ManuallyDrop<T>) -> T {
-        unsafe {
-            slot.value
-        }
+        slot.value
     }
 
     /// Manually drops the contained value.
@@ -1006,102 +1010,22 @@ impl<T> ManuallyDrop<T> {
     }
 }
 
+#[cfg(not(stage0))]
 #[stable(feature = "manually_drop", since = "1.20.0")]
 impl<T> Deref for ManuallyDrop<T> {
     type Target = T;
     #[inline]
     fn deref(&self) -> &Self::Target {
-        unsafe {
-            &self.value
-        }
+        &self.value
     }
 }
 
+#[cfg(not(stage0))]
 #[stable(feature = "manually_drop", since = "1.20.0")]
 impl<T> DerefMut for ManuallyDrop<T> {
     #[inline]
     fn deref_mut(&mut self) -> &mut Self::Target {
-        unsafe {
-            &mut self.value
-        }
-    }
-}
-
-#[stable(feature = "manually_drop", since = "1.20.0")]
-impl<T: ::fmt::Debug> ::fmt::Debug for ManuallyDrop<T> {
-    fn fmt(&self, fmt: &mut ::fmt::Formatter) -> ::fmt::Result {
-        unsafe {
-            fmt.debug_tuple("ManuallyDrop").field(&self.value).finish()
-        }
-    }
-}
-
-#[stable(feature = "manually_drop_impls", since = "1.22.0")]
-impl<T: Clone> Clone for ManuallyDrop<T> {
-    fn clone(&self) -> Self {
-        ManuallyDrop::new(self.deref().clone())
-    }
-
-    fn clone_from(&mut self, source: &Self) {
-        self.deref_mut().clone_from(source);
-    }
-}
-
-#[stable(feature = "manually_drop_impls", since = "1.22.0")]
-impl<T: Default> Default for ManuallyDrop<T> {
-    fn default() -> Self {
-        ManuallyDrop::new(Default::default())
-    }
-}
-
-#[stable(feature = "manually_drop_impls", since = "1.22.0")]
-impl<T: PartialEq> PartialEq for ManuallyDrop<T> {
-    fn eq(&self, other: &Self) -> bool {
-        self.deref().eq(other)
-    }
-
-    fn ne(&self, other: &Self) -> bool {
-        self.deref().ne(other)
-    }
-}
-
-#[stable(feature = "manually_drop_impls", since = "1.22.0")]
-impl<T: Eq> Eq for ManuallyDrop<T> {}
-
-#[stable(feature = "manually_drop_impls", since = "1.22.0")]
-impl<T: PartialOrd> PartialOrd for ManuallyDrop<T> {
-    fn partial_cmp(&self, other: &Self) -> Option<::cmp::Ordering> {
-        self.deref().partial_cmp(other)
-    }
-
-    fn lt(&self, other: &Self) -> bool {
-        self.deref().lt(other)
-    }
-
-    fn le(&self, other: &Self) -> bool {
-        self.deref().le(other)
-    }
-
-    fn gt(&self, other: &Self) -> bool {
-        self.deref().gt(other)
-    }
-
-    fn ge(&self, other: &Self) -> bool {
-        self.deref().ge(other)
-    }
-}
-
-#[stable(feature = "manually_drop_impls", since = "1.22.0")]
-impl<T: Ord> Ord for ManuallyDrop<T> {
-    fn cmp(&self, other: &Self) -> ::cmp::Ordering {
-        self.deref().cmp(other)
-    }
-}
-
-#[stable(feature = "manually_drop_impls", since = "1.22.0")]
-impl<T: ::hash::Hash> ::hash::Hash for ManuallyDrop<T> {
-    fn hash<H: ::hash::Hasher>(&self, state: &mut H) {
-        self.deref().hash(state);
+        &mut self.value
     }
 }