diff --git a/src/doc/nomicon b/src/doc/nomicon
index 616b98444ff4e..6fa139b1630a9 160000
--- a/src/doc/nomicon
+++ b/src/doc/nomicon
@@ -1 +1 @@
-Subproject commit 616b98444ff4eb5260deee95ee3e090dfd98b947
+Subproject commit 6fa139b1630a9bb95dcd60cfc90aff9c19e54580
diff --git a/src/liballoc/arc.rs b/src/liballoc/arc.rs
index 182a107e3f769..921db3c6959b8 100644
--- a/src/liballoc/arc.rs
+++ b/src/liballoc/arc.rs
@@ -277,8 +277,7 @@ impl<T> Arc<T> {
         atomic::fence(Acquire);
 
         unsafe {
-            let ptr = *this.ptr;
-            let elem = ptr::read(&(*ptr).data);
+            let elem = ptr::read(&this.ptr.as_ref().data);
 
             // Make a weak pointer to clean up the implicit strong-weak reference
             let _weak = Weak { ptr: this.ptr };
@@ -306,7 +305,7 @@ impl<T> Arc<T> {
     /// ```
     #[stable(feature = "rc_raw", since = "1.17.0")]
     pub fn into_raw(this: Self) -> *const T {
-        let ptr = unsafe { &(**this.ptr).data as *const _ };
+        let ptr: *const T = &*this;
         mem::forget(this);
         ptr
     }
@@ -345,7 +344,7 @@ impl<T> Arc<T> {
         // `data` field from the pointer.
         let ptr = (ptr as *const u8).offset(-offset_of!(ArcInner<T>, data));
         Arc {
-            ptr: Shared::new(ptr as *const _),
+            ptr: Shared::new(ptr as *mut u8 as *mut _),
         }
     }
 }
@@ -452,17 +451,17 @@ impl<T: ?Sized> Arc<T> {
         // `ArcInner` structure itself is `Sync` because the inner data is
         // `Sync` as well, so we're ok loaning out an immutable pointer to these
         // contents.
-        unsafe { &**self.ptr }
+        unsafe { self.ptr.as_ref() }
     }
 
     // Non-inlined part of `drop`.
     #[inline(never)]
     unsafe fn drop_slow(&mut self) {
-        let ptr = self.ptr.as_mut_ptr();
+        let ptr = self.ptr.as_ptr();
 
         // Destroy the data at this time, even though we may not free the box
         // allocation itself (there may still be weak pointers lying around).
-        ptr::drop_in_place(&mut (*ptr).data);
+        ptr::drop_in_place(&mut self.ptr.as_mut().data);
 
         if self.inner().weak.fetch_sub(1, Release) == 1 {
             atomic::fence(Acquire);
@@ -488,9 +487,7 @@ impl<T: ?Sized> Arc<T> {
     /// assert!(!Arc::ptr_eq(&five, &other_five));
     /// ```
     pub fn ptr_eq(this: &Self, other: &Self) -> bool {
-        let this_ptr: *const ArcInner<T> = *this.ptr;
-        let other_ptr: *const ArcInner<T> = *other.ptr;
-        this_ptr == other_ptr
+        this.ptr.as_ptr() == other.ptr.as_ptr()
     }
 }
 
@@ -621,7 +618,7 @@ impl<T: Clone> Arc<T> {
                 // here (due to zeroing) because data is no longer accessed by
                 // other threads (due to there being no more strong refs at this
                 // point).
-                let mut swap = Arc::new(ptr::read(&(**weak.ptr).data));
+                let mut swap = Arc::new(ptr::read(&weak.ptr.as_ref().data));
                 mem::swap(this, &mut swap);
                 mem::forget(swap);
             }
@@ -634,8 +631,7 @@ impl<T: Clone> Arc<T> {
         // As with `get_mut()`, the unsafety is ok because our reference was
         // either unique to begin with, or became one upon cloning the contents.
         unsafe {
-            let inner = &mut *this.ptr.as_mut_ptr();
-            &mut inner.data
+            &mut this.ptr.as_mut().data
         }
     }
 }
@@ -677,8 +673,7 @@ impl<T: ?Sized> Arc<T> {
             // the Arc itself to be `mut`, so we're returning the only possible
             // reference to the inner data.
             unsafe {
-                let inner = &mut *this.ptr.as_mut_ptr();
-                Some(&mut inner.data)
+                Some(&mut this.ptr.as_mut().data)
             }
         } else {
             None
@@ -867,7 +862,7 @@ impl<T: ?Sized> Weak<T> {
     #[inline]
     fn inner(&self) -> &ArcInner<T> {
         // See comments above for why this is "safe"
-        unsafe { &**self.ptr }
+        unsafe { self.ptr.as_ref() }
     }
 }
 
@@ -951,7 +946,7 @@ impl<T: ?Sized> Drop for Weak<T> {
     /// assert!(other_weak_foo.upgrade().is_none());
     /// ```
     fn drop(&mut self) {
-        let ptr = *self.ptr;
+        let ptr = self.ptr.as_ptr();
 
         // If we find out that we were the last weak pointer, then its time to
         // deallocate the data entirely. See the discussion in Arc::drop() about
@@ -1132,7 +1127,7 @@ impl<T: ?Sized + fmt::Debug> fmt::Debug for Arc<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> fmt::Pointer for Arc<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Pointer::fmt(&*self.ptr, f)
+        fmt::Pointer::fmt(&self.ptr, f)
     }
 }
 
diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index b03e3bb7a4bdc..fc6929f896ecb 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -156,7 +156,7 @@ fn make_place<T>() -> IntermediateBox<T> {
     let align = mem::align_of::<T>();
 
     let p = if size == 0 {
-        heap::EMPTY as *mut u8
+        mem::align_of::<T>() as *mut u8
     } else {
         let p = unsafe { heap::allocate(size, align) };
         if p.is_null() {
diff --git a/src/liballoc/heap.rs b/src/liballoc/heap.rs
index 056af13016cf2..5ff21c86483c8 100644
--- a/src/liballoc/heap.rs
+++ b/src/liballoc/heap.rs
@@ -138,7 +138,9 @@ pub fn usable_size(size: usize, align: usize) -> usize {
 ///
 /// This preserves the non-null invariant for types like `Box<T>`. The address
 /// may overlap with non-zero-size memory allocations.
-pub const EMPTY: *mut () = 0x1 as *mut ();
+#[rustc_deprecated(since = "1.19", reason = "Use Unique/Shared::empty() instead")]
+#[unstable(feature = "heap_api", issue = "27700")]
+pub const EMPTY: *mut () = 1 as *mut ();
 
 /// The allocator for unique pointers.
 // This function must not unwind. If it does, MIR trans will fail.
@@ -147,7 +149,7 @@ pub const EMPTY: *mut () = 0x1 as *mut ();
 #[inline]
 unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 {
     if size == 0 {
-        EMPTY as *mut u8
+        align as *mut u8
     } else {
         let ptr = allocate(size, align);
         if ptr.is_null() {
diff --git a/src/liballoc/raw_vec.rs b/src/liballoc/raw_vec.rs
index 6a53d3a9ca57a..7edf07944ec50 100644
--- a/src/liballoc/raw_vec.rs
+++ b/src/liballoc/raw_vec.rs
@@ -22,13 +22,13 @@ use core::cmp;
 /// involved. This type is excellent for building your own data structures like Vec and VecDeque.
 /// In particular:
 ///
-/// * Produces heap::EMPTY on zero-sized types
-/// * Produces heap::EMPTY on zero-length allocations
+/// * Produces Unique::empty() on zero-sized types
+/// * Produces Unique::empty() on zero-length allocations
 /// * Catches all overflows in capacity computations (promotes them to "capacity overflow" panics)
 /// * Guards against 32-bit systems allocating more than isize::MAX bytes
 /// * Guards against overflowing your length
 /// * Aborts on OOM
-/// * Avoids freeing heap::EMPTY
+/// * Avoids freeing Unique::empty()
 /// * Contains a ptr::Unique and thus endows the user with all related benefits
 ///
 /// This type does not in anyway inspect the memory that it manages. When dropped it *will*
@@ -55,15 +55,13 @@ impl<T> RawVec<T> {
     /// it makes a RawVec with capacity `usize::MAX`. Useful for implementing
     /// delayed allocation.
     pub fn new() -> Self {
-        unsafe {
-            // !0 is usize::MAX. This branch should be stripped at compile time.
-            let cap = if mem::size_of::<T>() == 0 { !0 } else { 0 };
+        // !0 is usize::MAX. This branch should be stripped at compile time.
+        let cap = if mem::size_of::<T>() == 0 { !0 } else { 0 };
 
-            // heap::EMPTY doubles as "unallocated" and "zero-sized allocation"
-            RawVec {
-                ptr: Unique::new(heap::EMPTY as *mut T),
-                cap: cap,
-            }
+        // Unique::empty() doubles as "unallocated" and "zero-sized allocation"
+        RawVec {
+            ptr: Unique::empty(),
+            cap: cap,
         }
     }
 
@@ -101,7 +99,7 @@ impl<T> RawVec<T> {
 
             // handles ZSTs and `cap = 0` alike
             let ptr = if alloc_size == 0 {
-                heap::EMPTY as *mut u8
+                mem::align_of::<T>() as *mut u8
             } else {
                 let align = mem::align_of::<T>();
                 let ptr = if zeroed {
@@ -148,10 +146,10 @@ impl<T> RawVec<T> {
 
 impl<T> RawVec<T> {
     /// Gets a raw pointer to the start of the allocation. Note that this is
-    /// heap::EMPTY if `cap = 0` or T is zero-sized. In the former case, you must
+    /// Unique::empty() if `cap = 0` or T is zero-sized. In the former case, you must
     /// be careful.
     pub fn ptr(&self) -> *mut T {
-        *self.ptr
+        self.ptr.as_ptr()
     }
 
     /// Gets the capacity of the allocation.
@@ -563,7 +561,7 @@ unsafe impl<#[may_dangle] T> Drop for RawVec<T> {
 
             let num_bytes = elem_size * self.cap;
             unsafe {
-                heap::deallocate(*self.ptr as *mut _, num_bytes, align);
+                heap::deallocate(self.ptr() as *mut u8, num_bytes, align);
             }
         }
     }
diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 38dc914583517..d6dbf77bfac77 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -230,7 +230,7 @@ use core::cell::Cell;
 use core::cmp::Ordering;
 use core::fmt;
 use core::hash::{Hash, Hasher};
-use core::intrinsics::{abort, assume};
+use core::intrinsics::abort;
 use core::marker;
 use core::marker::Unsize;
 use core::mem::{self, align_of_val, forget, size_of, size_of_val, uninitialized};
@@ -358,7 +358,7 @@ impl<T> Rc<T> {
     /// ```
     #[stable(feature = "rc_raw", since = "1.17.0")]
     pub fn into_raw(this: Self) -> *const T {
-        let ptr = unsafe { &mut (*this.ptr.as_mut_ptr()).value as *const _ };
+        let ptr: *const T = &*this;
         mem::forget(this);
         ptr
     }
@@ -395,7 +395,11 @@ impl<T> Rc<T> {
     pub unsafe fn from_raw(ptr: *const T) -> Self {
         // To find the corresponding pointer to the `RcBox` we need to subtract the offset of the
         // `value` field from the pointer.
-        Rc { ptr: Shared::new((ptr as *const u8).offset(-offset_of!(RcBox<T>, value)) as *const _) }
+
+        let ptr = (ptr as *const u8).offset(-offset_of!(RcBox<T>, value));
+        Rc {
+            ptr: Shared::new(ptr as *mut u8 as *mut _)
+        }
     }
 }
 
@@ -451,7 +455,7 @@ impl<T> Rc<[T]> {
             // Free the original allocation without freeing its (moved) contents.
             box_free(Box::into_raw(value));
 
-            Rc { ptr: Shared::new(ptr as *const _) }
+            Rc { ptr: Shared::new(ptr as *mut _) }
         }
     }
 }
@@ -553,8 +557,9 @@ impl<T: ?Sized> Rc<T> {
     #[stable(feature = "rc_unique", since = "1.4.0")]
     pub fn get_mut(this: &mut Self) -> Option<&mut T> {
         if Rc::is_unique(this) {
-            let inner = unsafe { &mut *this.ptr.as_mut_ptr() };
-            Some(&mut inner.value)
+            unsafe {
+                Some(&mut this.ptr.as_mut().value)
+            }
         } else {
             None
         }
@@ -578,9 +583,7 @@ impl<T: ?Sized> Rc<T> {
     /// assert!(!Rc::ptr_eq(&five, &other_five));
     /// ```
     pub fn ptr_eq(this: &Self, other: &Self) -> bool {
-        let this_ptr: *const RcBox<T> = *this.ptr;
-        let other_ptr: *const RcBox<T> = *other.ptr;
-        this_ptr == other_ptr
+        this.ptr.as_ptr() == other.ptr.as_ptr()
     }
 }
 
@@ -623,7 +626,7 @@ impl<T: Clone> Rc<T> {
         } else if Rc::weak_count(this) != 0 {
             // Can just steal the data, all that's left is Weaks
             unsafe {
-                let mut swap = Rc::new(ptr::read(&(**this.ptr).value));
+                let mut swap = Rc::new(ptr::read(&this.ptr.as_ref().value));
                 mem::swap(this, &mut swap);
                 swap.dec_strong();
                 // Remove implicit strong-weak ref (no need to craft a fake
@@ -637,8 +640,9 @@ impl<T: Clone> Rc<T> {
         // reference count is guaranteed to be 1 at this point, and we required
         // the `Rc<T>` itself to be `mut`, so we're returning the only possible
         // reference to the inner value.
-        let inner = unsafe { &mut *this.ptr.as_mut_ptr() };
-        &mut inner.value
+        unsafe {
+            &mut this.ptr.as_mut().value
+        }
     }
 }
 
@@ -683,12 +687,12 @@ unsafe impl<#[may_dangle] T: ?Sized> Drop for Rc<T> {
     /// ```
     fn drop(&mut self) {
         unsafe {
-            let ptr = self.ptr.as_mut_ptr();
+            let ptr = self.ptr.as_ptr();
 
             self.dec_strong();
             if self.strong() == 0 {
                 // destroy the contained object
-                ptr::drop_in_place(&mut (*ptr).value);
+                ptr::drop_in_place(self.ptr.as_mut());
 
                 // remove the implicit "strong weak" pointer now that we've
                 // destroyed the contents.
@@ -925,7 +929,7 @@ impl<T: ?Sized + fmt::Debug> fmt::Debug for Rc<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> fmt::Pointer for Rc<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Pointer::fmt(&*self.ptr, f)
+        fmt::Pointer::fmt(&self.ptr, f)
     }
 }
 
@@ -1067,7 +1071,7 @@ impl<T: ?Sized> Drop for Weak<T> {
     /// ```
     fn drop(&mut self) {
         unsafe {
-            let ptr = *self.ptr;
+            let ptr = self.ptr.as_ptr();
 
             self.dec_weak();
             // the weak count starts at 1, and will only go to zero if all
@@ -1175,12 +1179,7 @@ impl<T: ?Sized> RcBoxPtr<T> for Rc<T> {
     #[inline(always)]
     fn inner(&self) -> &RcBox<T> {
         unsafe {
-            // Safe to assume this here, as if it weren't true, we'd be breaking
-            // the contract anyway.
-            // This allows the null check to be elided in the destructor if we
-            // manipulated the reference count in the same function.
-            assume(!(*(&self.ptr as *const _ as *const *const ())).is_null());
-            &(**self.ptr)
+            self.ptr.as_ref()
         }
     }
 }
@@ -1189,12 +1188,7 @@ impl<T: ?Sized> RcBoxPtr<T> for Weak<T> {
     #[inline(always)]
     fn inner(&self) -> &RcBox<T> {
         unsafe {
-            // Safe to assume this here, as if it weren't true, we'd be breaking
-            // the contract anyway.
-            // This allows the null check to be elided in the destructor if we
-            // manipulated the reference count in the same function.
-            assume(!(*(&self.ptr as *const _ as *const *const ())).is_null());
-            &(**self.ptr)
+            self.ptr.as_ref()
         }
     }
 }
diff --git a/src/libarena/lib.rs b/src/libarena/lib.rs
index a3cfc15895eb7..321fa2edd56c7 100644
--- a/src/libarena/lib.rs
+++ b/src/libarena/lib.rs
@@ -31,7 +31,6 @@
 #![feature(alloc)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
-#![feature(heap_api)]
 #![feature(generic_param_attrs)]
 #![feature(staged_api)]
 #![cfg_attr(test, feature(test))]
@@ -48,7 +47,6 @@ use std::mem;
 use std::ptr;
 use std::slice;
 
-use alloc::heap;
 use alloc::raw_vec::RawVec;
 
 /// An arena that can hold objects of only one type.
@@ -140,7 +138,7 @@ impl<T> TypedArena<T> {
         unsafe {
             if mem::size_of::<T>() == 0 {
                 self.ptr.set(intrinsics::arith_offset(self.ptr.get() as *mut u8, 1) as *mut T);
-                let ptr = heap::EMPTY as *mut T;
+                let ptr = mem::align_of::<T>() as *mut T;
                 // Don't drop the object. This `write` is equivalent to `forget`.
                 ptr::write(ptr, object);
                 &mut *ptr
diff --git a/src/libcollections/btree/node.rs b/src/libcollections/btree/node.rs
index e9bc29118d508..52cdd39d8f963 100644
--- a/src/libcollections/btree/node.rs
+++ b/src/libcollections/btree/node.rs
@@ -152,12 +152,12 @@ impl<K, V> BoxedNode<K, V> {
     }
 
     unsafe fn from_ptr(ptr: NonZero<*const LeafNode<K, V>>) -> Self {
-        BoxedNode { ptr: Unique::new(*ptr as *mut LeafNode<K, V>) }
+        BoxedNode { ptr: Unique::new(ptr.get() as *mut LeafNode<K, V>) }
     }
 
     fn as_ptr(&self) -> NonZero<*const LeafNode<K, V>> {
         unsafe {
-            NonZero::new(*self.ptr as *const LeafNode<K, V>)
+            NonZero::new(self.ptr.as_ptr())
         }
     }
 }
@@ -241,7 +241,7 @@ impl<K, V> Root<K, V> {
     pub fn pop_level(&mut self) {
         debug_assert!(self.height > 0);
 
-        let top = *self.node.ptr as *mut u8;
+        let top = self.node.ptr.as_ptr() as *mut u8;
 
         self.node = unsafe {
             BoxedNode::from_ptr(self.as_mut()
@@ -308,7 +308,7 @@ unsafe impl<K: Send, V: Send, Type> Send
 impl<BorrowType, K, V> NodeRef<BorrowType, K, V, marker::Internal> {
     fn as_internal(&self) -> &InternalNode<K, V> {
         unsafe {
-            &*(*self.node as *const InternalNode<K, V>)
+            &*(self.node.get() as *const InternalNode<K, V>)
         }
     }
 }
@@ -316,7 +316,7 @@ impl<BorrowType, K, V> NodeRef<BorrowType, K, V, marker::Internal> {
 impl<'a, K, V> NodeRef<marker::Mut<'a>, K, V, marker::Internal> {
     fn as_internal_mut(&mut self) -> &mut InternalNode<K, V> {
         unsafe {
-            &mut *(*self.node as *mut InternalNode<K, V>)
+            &mut *(self.node.get() as *mut InternalNode<K, V>)
         }
     }
 }
@@ -358,7 +358,7 @@ impl<BorrowType, K, V, Type> NodeRef<BorrowType, K, V, Type> {
 
     fn as_leaf(&self) -> &LeafNode<K, V> {
         unsafe {
-            &**self.node
+            &*self.node.get()
         }
     }
 
@@ -510,7 +510,7 @@ impl<'a, K, V, Type> NodeRef<marker::Mut<'a>, K, V, Type> {
 
     fn as_leaf_mut(&mut self) -> &mut LeafNode<K, V> {
         unsafe {
-            &mut *(*self.node as *mut LeafNode<K, V>)
+            &mut *(self.node.get() as *mut LeafNode<K, V>)
         }
     }
 
@@ -1253,13 +1253,13 @@ impl<'a, K, V> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Internal>, marker::
                 }
 
                 heap::deallocate(
-                    *right_node.node as *mut u8,
+                    right_node.node.get() as *mut u8,
                     mem::size_of::<InternalNode<K, V>>(),
                     mem::align_of::<InternalNode<K, V>>()
                 );
             } else {
                 heap::deallocate(
-                    *right_node.node as *mut u8,
+                    right_node.node.get() as *mut u8,
                     mem::size_of::<LeafNode<K, V>>(),
                     mem::align_of::<LeafNode<K, V>>()
                 );
diff --git a/src/libcollections/linked_list.rs b/src/libcollections/linked_list.rs
index adfd91bec4893..ae258083546f4 100644
--- a/src/libcollections/linked_list.rs
+++ b/src/libcollections/linked_list.rs
@@ -161,7 +161,7 @@ impl<T> LinkedList<T> {
 
             match self.head {
                 None => self.tail = node,
-                Some(head) => (*head.as_mut_ptr()).prev = node,
+                Some(mut head) => head.as_mut().prev = node,
             }
 
             self.head = node;
@@ -173,12 +173,12 @@ impl<T> LinkedList<T> {
     #[inline]
     fn pop_front_node(&mut self) -> Option<Box<Node<T>>> {
         self.head.map(|node| unsafe {
-            let node = Box::from_raw(node.as_mut_ptr());
+            let node = Box::from_raw(node.as_ptr());
             self.head = node.next;
 
             match self.head {
                 None => self.tail = None,
-                Some(head) => (*head.as_mut_ptr()).prev = None,
+                Some(mut head) => head.as_mut().prev = None,
             }
 
             self.len -= 1;
@@ -196,7 +196,7 @@ impl<T> LinkedList<T> {
 
             match self.tail {
                 None => self.head = node,
-                Some(tail) => (*tail.as_mut_ptr()).next = node,
+                Some(mut tail) => tail.as_mut().next = node,
             }
 
             self.tail = node;
@@ -208,12 +208,12 @@ impl<T> LinkedList<T> {
     #[inline]
     fn pop_back_node(&mut self) -> Option<Box<Node<T>>> {
         self.tail.map(|node| unsafe {
-            let node = Box::from_raw(node.as_mut_ptr());
+            let node = Box::from_raw(node.as_ptr());
             self.tail = node.prev;
 
             match self.tail {
                 None => self.head = None,
-                Some(tail) => (*tail.as_mut_ptr()).next = None,
+                Some(mut tail) => tail.as_mut().next = None,
             }
 
             self.len -= 1;
@@ -285,11 +285,11 @@ impl<T> LinkedList<T> {
     pub fn append(&mut self, other: &mut Self) {
         match self.tail {
             None => mem::swap(self, other),
-            Some(tail) => {
-                if let Some(other_head) = other.head.take() {
+            Some(mut tail) => {
+                if let Some(mut other_head) = other.head.take() {
                     unsafe {
-                        (*tail.as_mut_ptr()).next = Some(other_head);
-                        (*other_head.as_mut_ptr()).prev = Some(tail);
+                        tail.as_mut().next = Some(other_head);
+                        other_head.as_mut().prev = Some(tail);
                     }
 
                     self.tail = other.tail.take();
@@ -477,7 +477,9 @@ impl<T> LinkedList<T> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn front(&self) -> Option<&T> {
-        self.head.map(|node| unsafe { &(**node).element })
+        unsafe {
+            self.head.as_ref().map(|node| &node.as_ref().element)
+        }
     }
 
     /// Provides a mutable reference to the front element, or `None` if the list
@@ -503,7 +505,9 @@ impl<T> LinkedList<T> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn front_mut(&mut self) -> Option<&mut T> {
-        self.head.map(|node| unsafe { &mut (*node.as_mut_ptr()).element })
+        unsafe {
+            self.head.as_mut().map(|node| &mut node.as_mut().element)
+        }
     }
 
     /// Provides a reference to the back element, or `None` if the list is
@@ -523,7 +527,9 @@ impl<T> LinkedList<T> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn back(&self) -> Option<&T> {
-        self.tail.map(|node| unsafe { &(**node).element })
+        unsafe {
+            self.tail.as_ref().map(|node| &node.as_ref().element)
+        }
     }
 
     /// Provides a mutable reference to the back element, or `None` if the list
@@ -549,7 +555,9 @@ impl<T> LinkedList<T> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn back_mut(&mut self) -> Option<&mut T> {
-        self.tail.map(|node| unsafe { &mut (*node.as_mut_ptr()).element })
+        unsafe {
+            self.tail.as_mut().map(|node| &mut node.as_mut().element)
+        }
     }
 
     /// Adds an element first in the list.
@@ -694,9 +702,9 @@ impl<T> LinkedList<T> {
         let second_part_head;
 
         unsafe {
-            second_part_head = (*split_node.unwrap().as_mut_ptr()).next.take();
-            if let Some(head) = second_part_head {
-                (*head.as_mut_ptr()).prev = None;
+            second_part_head = split_node.unwrap().as_mut().next.take();
+            if let Some(mut head) = second_part_head {
+                head.as_mut().prev = None;
             }
         }
 
@@ -788,7 +796,8 @@ impl<'a, T> Iterator for Iter<'a, T> {
             None
         } else {
             self.head.map(|node| unsafe {
-                let node = &**node;
+                // Need an unbound lifetime to get 'a
+                let node = &*node.as_ptr();
                 self.len -= 1;
                 self.head = node.next;
                 &node.element
@@ -810,7 +819,8 @@ impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
             None
         } else {
             self.tail.map(|node| unsafe {
-                let node = &**node;
+                // Need an unbound lifetime to get 'a
+                let node = &*node.as_ptr();
                 self.len -= 1;
                 self.tail = node.prev;
                 &node.element
@@ -835,7 +845,8 @@ impl<'a, T> Iterator for IterMut<'a, T> {
             None
         } else {
             self.head.map(|node| unsafe {
-                let node = &mut *node.as_mut_ptr();
+                // Need an unbound lifetime to get 'a
+                let node = &mut *node.as_ptr();
                 self.len -= 1;
                 self.head = node.next;
                 &mut node.element
@@ -857,7 +868,8 @@ impl<'a, T> DoubleEndedIterator for IterMut<'a, T> {
             None
         } else {
             self.tail.map(|node| unsafe {
-                let node = &mut *node.as_mut_ptr();
+                // Need an unbound lifetime to get 'a
+                let node = &mut *node.as_ptr();
                 self.len -= 1;
                 self.tail = node.prev;
                 &mut node.element
@@ -903,8 +915,8 @@ impl<'a, T> IterMut<'a, T> {
     pub fn insert_next(&mut self, element: T) {
         match self.head {
             None => self.list.push_back(element),
-            Some(head) => unsafe {
-                let prev = match (**head).prev {
+            Some(mut head) => unsafe {
+                let mut prev = match head.as_ref().prev {
                     None => return self.list.push_front(element),
                     Some(prev) => prev,
                 };
@@ -915,8 +927,8 @@ impl<'a, T> IterMut<'a, T> {
                     element: element,
                 })));
 
-                (*prev.as_mut_ptr()).next = node;
-                (*head.as_mut_ptr()).prev = node;
+                prev.as_mut().next = node;
+                head.as_mut().prev = node;
 
                 self.list.len += 1;
             },
@@ -948,7 +960,9 @@ impl<'a, T> IterMut<'a, T> {
         if self.len == 0 {
             None
         } else {
-            self.head.map(|node| unsafe { &mut (*node.as_mut_ptr()).element })
+            unsafe {
+                self.head.as_mut().map(|node| &mut node.as_mut().element)
+            }
         }
     }
 }
@@ -1276,21 +1290,21 @@ mod tests {
                     assert_eq!(0, list.len);
                     return;
                 }
-                Some(node) => node_ptr = &**node,
+                Some(node) => node_ptr = &*node.as_ptr(),
             }
             loop {
                 match (last_ptr, node_ptr.prev) {
                     (None, None) => {}
                     (None, _) => panic!("prev link for head"),
                     (Some(p), Some(pptr)) => {
-                        assert_eq!(p as *const Node<T>, *pptr as *const Node<T>);
+                        assert_eq!(p as *const Node<T>, pptr.as_ptr() as *const Node<T>);
                     }
                     _ => panic!("prev link is none, not good"),
                 }
                 match node_ptr.next {
                     Some(next) => {
                         last_ptr = Some(node_ptr);
-                        node_ptr = &**next;
+                        node_ptr = &*next.as_ptr();
                         len += 1;
                     }
                     None => {
diff --git a/src/libcollections/vec.rs b/src/libcollections/vec.rs
index fc5de70e98387..7ec5c29de6b4b 100644
--- a/src/libcollections/vec.rs
+++ b/src/libcollections/vec.rs
@@ -67,7 +67,6 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 use alloc::boxed::Box;
-use alloc::heap::EMPTY;
 use alloc::raw_vec::RawVec;
 use borrow::ToOwned;
 use borrow::Cow;
@@ -1776,9 +1775,9 @@ impl<T> SpecExtend<T, IntoIter<T>> for Vec<T> {
         // A common case is passing a vector into a function which immediately
         // re-collects into a vector. We can short circuit this if the IntoIter
         // has not been advanced at all.
-        if *iterator.buf == iterator.ptr as *mut T {
+        if iterator.buf.as_ptr() as *const _ == iterator.ptr {
             unsafe {
-                let vec = Vec::from_raw_parts(*iterator.buf as *mut T,
+                let vec = Vec::from_raw_parts(iterator.buf.as_ptr(),
                                               iterator.len(),
                                               iterator.cap);
                 mem::forget(iterator);
@@ -2192,7 +2191,8 @@ impl<T> Iterator for IntoIter<T> {
                     self.ptr = arith_offset(self.ptr as *const i8, 1) as *mut T;
 
                     // Use a non-null pointer value
-                    Some(ptr::read(EMPTY as *mut T))
+                    // (self.ptr might be null because of wrapping)
+                    Some(ptr::read(1 as *mut T))
                 } else {
                     let old = self.ptr;
                     self.ptr = self.ptr.offset(1);
@@ -2231,7 +2231,8 @@ impl<T> DoubleEndedIterator for IntoIter<T> {
                     self.end = arith_offset(self.end as *const i8, -1) as *mut T;
 
                     // Use a non-null pointer value
-                    Some(ptr::read(EMPTY as *mut T))
+                    // (self.end might be null because of wrapping)
+                    Some(ptr::read(1 as *mut T))
                 } else {
                     self.end = self.end.offset(-1);
 
@@ -2269,7 +2270,7 @@ unsafe impl<#[may_dangle] T> Drop for IntoIter<T> {
         for _x in self.by_ref() {}
 
         // RawVec handles deallocation
-        let _ = unsafe { RawVec::from_raw_parts(self.buf.as_mut_ptr(), self.cap) };
+        let _ = unsafe { RawVec::from_raw_parts(self.buf.as_ptr(), self.cap) };
     }
 }
 
@@ -2334,7 +2335,7 @@ impl<'a, T> Drop for Drain<'a, T> {
 
         if self.tail_len > 0 {
             unsafe {
-                let source_vec = &mut *self.vec.as_mut_ptr();
+                let source_vec = self.vec.as_mut();
                 // memmove back untouched tail, update to new length
                 let start = source_vec.len();
                 let tail = self.tail_start;
@@ -2456,8 +2457,7 @@ impl<'a, I: Iterator> Drop for Splice<'a, I> {
 
         unsafe {
             if self.drain.tail_len == 0 {
-                let vec = &mut *self.drain.vec.as_mut_ptr();
-                vec.extend(self.replace_with.by_ref());
+                self.drain.vec.as_mut().extend(self.replace_with.by_ref());
                 return
             }
 
@@ -2498,7 +2498,7 @@ impl<'a, T> Drain<'a, T> {
     /// Fill that range as much as possible with new elements from the `replace_with` iterator.
     /// Return whether we filled the entire range. (`replace_with.next()` didn’t return `None`.)
     unsafe fn fill<I: Iterator<Item=T>>(&mut self, replace_with: &mut I) -> bool {
-        let vec = &mut *self.vec.as_mut_ptr();
+        let vec = self.vec.as_mut();
         let range_start = vec.len;
         let range_end = self.tail_start;
         let range_slice = slice::from_raw_parts_mut(
@@ -2518,7 +2518,7 @@ impl<'a, T> Drain<'a, T> {
 
     /// Make room for inserting more elements before the tail.
     unsafe fn move_tail(&mut self, extra_capacity: usize) {
-        let vec = &mut *self.vec.as_mut_ptr();
+        let vec = self.vec.as_mut();
         let used_capacity = self.tail_start + self.tail_len;
         vec.buf.reserve(used_capacity, extra_capacity);
 
diff --git a/src/libcollections/vec_deque.rs b/src/libcollections/vec_deque.rs
index 079d3acf3764a..e826c9432b516 100644
--- a/src/libcollections/vec_deque.rs
+++ b/src/libcollections/vec_deque.rs
@@ -2160,7 +2160,7 @@ impl<'a, T: 'a> Drop for Drain<'a, T> {
     fn drop(&mut self) {
         for _ in self.by_ref() {}
 
-        let source_deque = unsafe { &mut *self.deque.as_mut_ptr() };
+        let source_deque = unsafe { self.deque.as_mut() };
 
         // T = source_deque_tail; H = source_deque_head; t = drain_tail; h = drain_head
         //
diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index f62057b3a52d0..7886f90b66e85 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -132,7 +132,6 @@
 //! use std::cell::Cell;
 //! use std::ptr::Shared;
 //! use std::intrinsics::abort;
-//! use std::intrinsics::assume;
 //!
 //! struct Rc<T: ?Sized> {
 //!     ptr: Shared<RcBox<T>>
@@ -171,8 +170,7 @@
 //! impl<T: ?Sized> RcBoxPtr<T> for Rc<T> {
 //!    fn inner(&self) -> &RcBox<T> {
 //!        unsafe {
-//!            assume(!(*(&self.ptr as *const _ as *const *const ())).is_null());
-//!            &(**self.ptr)
+//!            self.ptr.as_ref()
 //!        }
 //!    }
 //! }
diff --git a/src/libcore/nonzero.rs b/src/libcore/nonzero.rs
index d7382501bc325..d93085e96dbb2 100644
--- a/src/libcore/nonzero.rs
+++ b/src/libcore/nonzero.rs
@@ -13,7 +13,7 @@
             reason = "needs an RFC to flesh out the design",
             issue = "27730")]
 
-use ops::{CoerceUnsized, Deref};
+use ops::CoerceUnsized;
 
 /// Unsafe trait to indicate what types are usable with the NonZero struct
 pub unsafe trait Zeroable {}
@@ -46,15 +46,10 @@ impl<T: Zeroable> NonZero<T> {
     pub const unsafe fn new(inner: T) -> NonZero<T> {
         NonZero(inner)
     }
-}
-
-impl<T: Zeroable> Deref for NonZero<T> {
-    type Target = T;
 
-    #[inline]
-    fn deref(&self) -> &T {
-        let NonZero(ref inner) = *self;
-        inner
+    /// Gets the inner value.
+    pub fn get(self) -> T {
+        self.0
     }
 }
 
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index 115326bb9169a..a60abefc07650 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -17,7 +17,7 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 use intrinsics;
-use ops::{CoerceUnsized, Deref};
+use ops::CoerceUnsized;
 use fmt;
 use hash;
 use marker::{PhantomData, Unsize};
@@ -957,13 +957,25 @@ impl<T: ?Sized> PartialOrd for *mut T {
 }
 
 /// A wrapper around a raw non-null `*mut T` that indicates that the possessor
-/// of this wrapper owns the referent. This in turn implies that the
-/// `Unique<T>` is `Send`/`Sync` if `T` is `Send`/`Sync`, unlike a raw
-/// `*mut T` (which conveys no particular ownership semantics).  It
-/// also implies that the referent of the pointer should not be
-/// modified without a unique path to the `Unique` reference. Useful
-/// for building abstractions like `Vec<T>` or `Box<T>`, which
-/// internally use raw pointers to manage the memory that they own.
+/// of this wrapper owns the referent. Useful for building abstractions like
+/// `Box<T>`, `Vec<T>`, `String`, and `HashMap<K, V>`.
+///
+/// Unlike `*mut T`, `Unique<T>` behaves "as if" it were an instance of `T`.
+/// It implements `Send`/`Sync` if `T` is `Send`/`Sync`. It also implies
+/// the kind of strong aliasing guarantees an instance of `T` can expect:
+/// the referent of the pointer should not be modified without a unique path to
+/// its owning Unique.
+///
+/// If you're uncertain of whether it's correct to use `Unique` for your purposes,
+/// consider using `Shared`, which has weaker semantics.
+///
+/// Unlike `*mut T`, the pointer must always be non-null, even if the pointer
+/// is never dereferenced. This is so that enums may use this forbidden value
+/// as a discriminant -- `Option<Unique<T>>` has the same size as `Unique<T>`.
+/// However the pointer may still dangle if it isn't dereferenced.
+///
+/// Unlike `*mut T`, `Unique<T>` is covariant over `T`. This should always be correct
+/// for any type which upholds Unique's aliasing requirements.
 #[allow(missing_debug_implementations)]
 #[unstable(feature = "unique", reason = "needs an RFC to flesh out design",
            issue = "27730")]
@@ -991,6 +1003,20 @@ unsafe impl<T: Send + ?Sized> Send for Unique<T> { }
 #[unstable(feature = "unique", issue = "27730")]
 unsafe impl<T: Sync + ?Sized> Sync for Unique<T> { }
 
+#[unstable(feature = "unique", issue = "27730")]
+impl<T: Sized> Unique<T> {
+    /// Creates a new `Shared` that is dangling, but well-aligned.
+    ///
+    /// This is useful for initializing types which lazily allocate, like
+    /// `Vec::new` does.
+    pub fn empty() -> Self {
+        unsafe {
+            let ptr = mem::align_of::<T>() as *mut T;
+            Unique::new(ptr)
+        }
+    }
+}
+
 #[unstable(feature = "unique", issue = "27730")]
 impl<T: ?Sized> Unique<T> {
     /// Creates a new `Unique`.
@@ -1002,41 +1028,72 @@ impl<T: ?Sized> Unique<T> {
         Unique { pointer: NonZero::new(ptr), _marker: PhantomData }
     }
 
+    /// Acquires the underlying `*mut` pointer.
+    pub fn as_ptr(self) -> *mut T {
+        self.pointer.get() as *mut T
+    }
+
     /// Dereferences the content.
-    pub unsafe fn get(&self) -> &T {
-        &**self.pointer
+    ///
+    /// The resulting lifetime is bound to self so this behaves "as if"
+    /// it were actually an instance of T that is getting borrowed. If a longer
+    /// (unbound) lifetime is needed, use `&*my_ptr.ptr()`.
+    pub unsafe fn as_ref(&self) -> &T {
+        &*self.as_ptr()
     }
 
     /// Mutably dereferences the content.
-    pub unsafe fn get_mut(&mut self) -> &mut T {
-        &mut ***self
+    ///
+    /// The resulting lifetime is bound to self so this behaves "as if"
+    /// it were actually an instance of T that is getting borrowed. If a longer
+    /// (unbound) lifetime is needed, use `&mut *my_ptr.ptr()`.
+    pub unsafe fn as_mut(&mut self) -> &mut T {
+        &mut *self.as_ptr()
     }
 }
 
-#[unstable(feature = "unique", issue = "27730")]
-impl<T: ?Sized, U: ?Sized> CoerceUnsized<Unique<U>> for Unique<T> where T: Unsize<U> { }
-
-#[unstable(feature = "unique", issue= "27730")]
-impl<T:?Sized> Deref for Unique<T> {
-    type Target = *mut T;
-
-    #[inline]
-    fn deref(&self) -> &*mut T {
-        unsafe { mem::transmute(&*self.pointer) }
+#[unstable(feature = "shared", issue = "27730")]
+impl<T: ?Sized> Clone for Unique<T> {
+    fn clone(&self) -> Self {
+        *self
     }
 }
 
+#[unstable(feature = "shared", issue = "27730")]
+impl<T: ?Sized> Copy for Unique<T> { }
+
+#[unstable(feature = "unique", issue = "27730")]
+impl<T: ?Sized, U: ?Sized> CoerceUnsized<Unique<U>> for Unique<T> where T: Unsize<U> { }
+
 #[unstable(feature = "unique", issue = "27730")]
-impl<T> fmt::Pointer for Unique<T> {
+impl<T: ?Sized> fmt::Pointer for Unique<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Pointer::fmt(&*self.pointer, f)
+        fmt::Pointer::fmt(&self.as_ptr(), f)
     }
 }
 
-/// A wrapper around a raw non-null `*mut T` that indicates that the possessor
+/// A wrapper around a raw `*mut T` that indicates that the possessor
 /// of this wrapper has shared ownership of the referent. Useful for
-/// building abstractions like `Rc<T>` or `Arc<T>`, which internally
-/// use raw pointers to manage the memory that they own.
+/// building abstractions like `Rc<T>`, `Arc<T>`, or doubly-linked lists, which
+/// internally use aliased raw pointers to manage the memory that they own.
+///
+/// This is similar to `Unique`, except that it doesn't make any aliasing
+/// guarantees, and doesn't derive Send and Sync. Note that unlike `&T`,
+/// Shared has no special mutability requirements. Shared may mutate data
+/// aliased by other Shared pointers. More precise rules require Rust to
+/// develop an actual aliasing model.
+///
+/// Unlike `*mut T`, the pointer must always be non-null, even if the pointer
+/// is never dereferenced. This is so that enums may use this forbidden value
+/// as a discriminant -- `Option<Shared<T>>` has the same size as `Shared<T>`.
+/// However the pointer may still dangle if it isn't dereferenced.
+///
+/// Unlike `*mut T`, `Shared<T>` is covariant over `T`. If this is incorrect
+/// for your use case, you should include some PhantomData in your type to
+/// provide invariance, such as `PhantomData<Cell<T>>` or `PhantomData<&'a mut T>`.
+/// Usually this won't be necessary; covariance is correct for Rc, Arc, and LinkedList
+/// because they provide a public API that follows the normal shared XOR mutable
+/// rules of Rust.
 #[allow(missing_debug_implementations)]
 #[unstable(feature = "shared", reason = "needs an RFC to flesh out design",
            issue = "27730")]
@@ -1060,6 +1117,20 @@ impl<T: ?Sized> !Send for Shared<T> { }
 #[unstable(feature = "shared", issue = "27730")]
 impl<T: ?Sized> !Sync for Shared<T> { }
 
+#[unstable(feature = "shared", issue = "27730")]
+impl<T: Sized> Shared<T> {
+    /// Creates a new `Shared` that is dangling, but well-aligned.
+    ///
+    /// This is useful for initializing types which lazily allocate, like
+    /// `Vec::new` does.
+    pub fn empty() -> Self {
+        unsafe {
+            let ptr = mem::align_of::<T>() as *mut T;
+            Shared::new(ptr)
+        }
+    }
+}
+
 #[unstable(feature = "shared", issue = "27730")]
 impl<T: ?Sized> Shared<T> {
     /// Creates a new `Shared`.
@@ -1067,16 +1138,38 @@ impl<T: ?Sized> Shared<T> {
     /// # Safety
     ///
     /// `ptr` must be non-null.
-    pub unsafe fn new(ptr: *const T) -> Self {
+    pub unsafe fn new(ptr: *mut T) -> Self {
         Shared { pointer: NonZero::new(ptr), _marker: PhantomData }
     }
-}
 
-#[unstable(feature = "shared", issue = "27730")]
-impl<T: ?Sized> Shared<T> {
+    /// Acquires the underlying `*mut` pointer.
+    pub fn as_ptr(self) -> *mut T {
+        self.pointer.get() as *mut T
+    }
+
+    /// Dereferences the content.
+    ///
+    /// The resulting lifetime is bound to self so this behaves "as if"
+    /// it were actually an instance of T that is getting borrowed. If a longer
+    /// (unbound) lifetime is needed, use `&*my_ptr.ptr()`.
+    pub unsafe fn as_ref(&self) -> &T {
+        &*self.as_ptr()
+    }
+
+    /// Mutably dereferences the content.
+    ///
+    /// The resulting lifetime is bound to self so this behaves "as if"
+    /// it were actually an instance of T that is getting borrowed. If a longer
+    /// (unbound) lifetime is needed, use `&mut *my_ptr.ptr_mut()`.
+    pub unsafe fn as_mut(&mut self) -> &mut T {
+        &mut *self.as_ptr()
+    }
+
     /// Acquires the underlying pointer as a `*mut` pointer.
+    #[rustc_deprecated(since = "1.19", reason = "renamed to `as_ptr` for ergonomics/consistency")]
+    #[unstable(feature = "shared", issue = "27730")]
     pub unsafe fn as_mut_ptr(&self) -> *mut T {
-        **self as _
+        self.as_ptr()
     }
 }
 
@@ -1094,18 +1187,8 @@ impl<T: ?Sized> Copy for Shared<T> { }
 impl<T: ?Sized, U: ?Sized> CoerceUnsized<Shared<U>> for Shared<T> where T: Unsize<U> { }
 
 #[unstable(feature = "shared", issue = "27730")]
-impl<T: ?Sized> Deref for Shared<T> {
-    type Target = *const T;
-
-    #[inline]
-    fn deref(&self) -> &*const T {
-        unsafe { mem::transmute(&*self.pointer) }
-    }
-}
-
-#[unstable(feature = "shared", issue = "27730")]
-impl<T> fmt::Pointer for Shared<T> {
+impl<T: ?Sized> fmt::Pointer for Shared<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Pointer::fmt(&*self.pointer, f)
+        fmt::Pointer::fmt(&self.as_ptr(), f)
     }
 }
diff --git a/src/libcore/tests/nonzero.rs b/src/libcore/tests/nonzero.rs
index 7a367ddeec8d4..588fffda35fca 100644
--- a/src/libcore/tests/nonzero.rs
+++ b/src/libcore/tests/nonzero.rs
@@ -31,12 +31,12 @@ fn test_match_on_nonzero_option() {
         NonZero::new(42)
     });
     match a {
-        Some(val) => assert_eq!(*val, 42),
+        Some(val) => assert_eq!(val.get(), 42),
         None => panic!("unexpected None while matching on Some(NonZero(_))")
     }
 
     match unsafe { Some(NonZero::new(43)) } {
-        Some(val) => assert_eq!(*val, 43),
+        Some(val) => assert_eq!(val.get(), 43),
         None => panic!("unexpected None while matching on Some(NonZero(_))")
     }
 }
diff --git a/src/libcore/tests/ptr.rs b/src/libcore/tests/ptr.rs
index 7f6f472bfbb78..e28dc6a6881fd 100644
--- a/src/libcore/tests/ptr.rs
+++ b/src/libcore/tests/ptr.rs
@@ -166,10 +166,10 @@ fn test_set_memory() {
 
 #[test]
 fn test_unsized_unique() {
-    let xs: &mut [i32] = &mut [1, 2, 3];
-    let ptr = unsafe { Unique::new(xs as *mut [i32]) };
-    let ys = unsafe { &mut **ptr };
-    let zs: &mut [i32] = &mut [1, 2, 3];
+    let xs: &[i32] = &[1, 2, 3];
+    let ptr = unsafe { Unique::new(xs as *const [i32] as *mut [i32]) };
+    let ys = unsafe { ptr.as_ref() };
+    let zs: &[i32] = &[1, 2, 3];
     assert!(ys == zs);
 }
 
diff --git a/src/libflate/lib.rs b/src/libflate/lib.rs
index dedec7b1609fa..3619be82829ca 100644
--- a/src/libflate/lib.rs
+++ b/src/libflate/lib.rs
@@ -62,14 +62,14 @@ pub struct Bytes {
 impl Deref for Bytes {
     type Target = [u8];
     fn deref(&self) -> &[u8] {
-        unsafe { slice::from_raw_parts(*self.ptr, self.len) }
+        unsafe { slice::from_raw_parts(self.ptr.as_ptr(), self.len) }
     }
 }
 
 impl Drop for Bytes {
     fn drop(&mut self) {
         unsafe {
-            libc::free(*self.ptr as *mut _);
+            libc::free(self.ptr.as_ptr() as *mut _);
         }
     }
 }
diff --git a/src/librustc/ty/subst.rs b/src/librustc/ty/subst.rs
index c591845dd63b1..c9ffcee51c20a 100644
--- a/src/librustc/ty/subst.rs
+++ b/src/librustc/ty/subst.rs
@@ -72,7 +72,7 @@ impl<'tcx> From<ty::Region<'tcx>> for Kind<'tcx> {
 impl<'tcx> Kind<'tcx> {
     #[inline]
     unsafe fn downcast<T>(self, tag: usize) -> Option<&'tcx T> {
-        let ptr = *self.ptr;
+        let ptr = self.ptr.get();
         if ptr & TAG_MASK == tag {
             Some(&*((ptr & !TAG_MASK) as *const _))
         } else {
@@ -102,7 +102,7 @@ impl<'tcx> fmt::Debug for Kind<'tcx> {
         } else if let Some(r) = self.as_region() {
             write!(f, "{:?}", r)
         } else {
-            write!(f, "<unknwon @ {:p}>", *self.ptr as *const ())
+            write!(f, "<unknwon @ {:p}>", self.ptr.get() as *const ())
         }
     }
 }
diff --git a/src/librustc_borrowck/borrowck/mir/gather_moves.rs b/src/librustc_borrowck/borrowck/mir/gather_moves.rs
index 81037fe40d9da..ed5e539f245f1 100644
--- a/src/librustc_borrowck/borrowck/mir/gather_moves.rs
+++ b/src/librustc_borrowck/borrowck/mir/gather_moves.rs
@@ -43,7 +43,7 @@ mod indexes {
                     unsafe { $Index(NonZero::new(idx + 1)) }
                 }
                 fn index(self) -> usize {
-                    *self.0 - 1
+                    self.0.get() - 1
                 }
             }
 
diff --git a/src/librustc_data_structures/array_vec.rs b/src/librustc_data_structures/array_vec.rs
index 848e5a076bb9a..078bb801751d0 100644
--- a/src/librustc_data_structures/array_vec.rs
+++ b/src/librustc_data_structures/array_vec.rs
@@ -255,7 +255,7 @@ impl<'a, A: Array> Drop for Drain<'a, A> {
 
         if self.tail_len > 0 {
             unsafe {
-                let source_array_vec = &mut *self.array_vec.as_mut_ptr();
+                let source_array_vec = self.array_vec.as_mut();
                 // memmove back untouched tail, update to new length
                 let start = source_array_vec.len();
                 let tail = self.tail_start;
diff --git a/src/librustc_data_structures/obligation_forest/node_index.rs b/src/librustc_data_structures/obligation_forest/node_index.rs
index 1063bb3611ef3..023c56ca59be8 100644
--- a/src/librustc_data_structures/obligation_forest/node_index.rs
+++ b/src/librustc_data_structures/obligation_forest/node_index.rs
@@ -23,6 +23,6 @@ impl NodeIndex {
     }
 
     pub fn get(self) -> usize {
-        (*self.index - 1) as usize
+        (self.index.get() - 1) as usize
     }
 }
diff --git a/src/libstd/collections/hash/table.rs b/src/libstd/collections/hash/table.rs
index 9623706548b32..a15269cc87c5d 100644
--- a/src/libstd/collections/hash/table.rs
+++ b/src/libstd/collections/hash/table.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use alloc::heap::{EMPTY, allocate, deallocate};
+use alloc::heap::{allocate, deallocate};
 
 use cmp;
 use hash::{BuildHasher, Hash, Hasher};
@@ -33,6 +33,7 @@ use self::BucketState::*;
 type HashUint = usize;
 
 const EMPTY_BUCKET: HashUint = 0;
+const EMPTY: usize = 1;
 
 /// Special `Unique<HashUint>` that uses the lower bit of the pointer
 /// to expose a boolean tag.
@@ -49,24 +50,25 @@ impl TaggedHashUintPtr {
 
     #[inline]
     fn set_tag(&mut self, value: bool) {
-        let usize_ptr = &*self.0 as *const *mut HashUint as *mut usize;
+        let mut usize_ptr = self.0.as_ptr() as usize;
         unsafe {
             if value {
-                *usize_ptr |= 1;
+                usize_ptr |= 1;
             } else {
-                *usize_ptr &= !1;
+                usize_ptr &= !1;
             }
+            self.0 = Unique::new(usize_ptr as *mut HashUint)
         }
     }
 
     #[inline]
     fn tag(&self) -> bool {
-        (*self.0 as usize) & 1 == 1
+        (self.0.as_ptr() as usize) & 1 == 1
     }
 
     #[inline]
     fn ptr(&self) -> *mut HashUint {
-        (*self.0 as usize & !1) as *mut HashUint
+        (self.0.as_ptr() as usize & !1) as *mut HashUint
     }
 }
 
@@ -1112,10 +1114,12 @@ impl<'a, K, V> Iterator for Drain<'a, K, V> {
 
     #[inline]
     fn next(&mut self) -> Option<(SafeHash, K, V)> {
-        self.iter.next().map(|raw| unsafe {
-            (*self.table.as_mut_ptr()).size -= 1;
-            let (k, v) = ptr::read(raw.pair());
-            (SafeHash { hash: ptr::replace(&mut *raw.hash(), EMPTY_BUCKET) }, k, v)
+        self.iter.next().map(|raw| {
+            unsafe {
+                self.table.as_mut().size -= 1;
+                let (k, v) = ptr::read(raw.pair());
+                (SafeHash { hash: ptr::replace(&mut *raw.hash(), EMPTY_BUCKET) }, k, v)
+            }
         })
     }