From 7a786d453519cd5fb73c16a5e0266fa1a864ffe0 Mon Sep 17 00:00:00 2001
From: Dale Wijnand <dale.wijnand@gmail.com>
Date: Wed, 19 Dec 2018 23:18:02 +0000
Subject: [PATCH 1/3] Add Into<NonNull<T>> impls for Arc<T>/Rc<T>

---
 src/liballoc/rc.rs        | 8 ++++++++
 src/liballoc/sync.rs      | 8 ++++++++
 src/liballoc/tests/arc.rs | 5 +++++
 src/liballoc/tests/rc.rs  | 5 +++++
 4 files changed, 26 insertions(+)

diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 6769a70ddbe0a..9b116b042ecb5 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -1179,6 +1179,14 @@ impl<T> From<Vec<T>> for Rc<[T]> {
     }
 }
 
+#[unstable(feature = "rc_into_nonnull", reason = "newly added", issue = "0")]
+impl<T: ?Sized> Into<NonNull<T>> for Rc<T> {
+    #[inline]
+    fn into(self) -> NonNull<T> {
+        unsafe { NonNull::new_unchecked(Rc::into_raw(self) as *mut _) }
+    }
+}
+
 /// `Weak` is a version of [`Rc`] that holds a non-owning reference to the
 /// managed value. The value is accessed by calling [`upgrade`] on the `Weak`
 /// pointer, which returns an [`Option`]`<`[`Rc`]`<T>>`.
diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs
index e596694fb9d4b..d6d213355b60f 100644
--- a/src/liballoc/sync.rs
+++ b/src/liballoc/sync.rs
@@ -1574,6 +1574,14 @@ impl<T> From<Vec<T>> for Arc<[T]> {
     }
 }
 
+#[unstable(feature = "arc_into_nonnull", reason = "newly added", issue = "0")]
+impl<T: ?Sized> Into<NonNull<T>> for Arc<T> {
+    #[inline]
+    fn into(self) -> NonNull<T> {
+        unsafe { NonNull::new_unchecked(Arc::into_raw(self) as *mut _) }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::boxed::Box;
diff --git a/src/liballoc/tests/arc.rs b/src/liballoc/tests/arc.rs
index ec589710216c3..8c19d704b3e58 100644
--- a/src/liballoc/tests/arc.rs
+++ b/src/liballoc/tests/arc.rs
@@ -95,3 +95,8 @@ fn eq() {
     assert!(!(x != x));
     assert_eq!(*x.0.borrow(), 0);
 }
+
+#[test]
+fn to_nonnull() {
+    let _: std::ptr::NonNull<i32> = Arc::new(0).into();
+}
diff --git a/src/liballoc/tests/rc.rs b/src/liballoc/tests/rc.rs
index 02e1dfe13bb36..0f618d1f9e6d8 100644
--- a/src/liballoc/tests/rc.rs
+++ b/src/liballoc/tests/rc.rs
@@ -95,3 +95,8 @@ fn eq() {
     assert!(!(x != x));
     assert_eq!(*x.0.borrow(), 0);
 }
+
+#[test]
+fn to_nonnull() {
+    let _: std::ptr::NonNull<i32> = Rc::new(0).into();
+}

From dd74e564dbb1558bc53ae65290fbf27979898c71 Mon Sep 17 00:00:00 2001
From: Dale Wijnand <dale.wijnand@gmail.com>
Date: Wed, 19 Dec 2018 23:31:27 +0000
Subject: [PATCH 2/3] Add assert_eq to Arc/Rc -> NonNull test

---
 src/liballoc/tests/arc.rs | 4 +++-
 src/liballoc/tests/rc.rs  | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/liballoc/tests/arc.rs b/src/liballoc/tests/arc.rs
index 8c19d704b3e58..3604466703828 100644
--- a/src/liballoc/tests/arc.rs
+++ b/src/liballoc/tests/arc.rs
@@ -98,5 +98,7 @@ fn eq() {
 
 #[test]
 fn to_nonnull() {
-    let _: std::ptr::NonNull<i32> = Arc::new(0).into();
+    let ptr: std::ptr::NonNull<i32> = Arc::new(0).into();
+    let deref = unsafe { *ptr.as_ref() };
+    assert_eq!(deref, 0);
 }
diff --git a/src/liballoc/tests/rc.rs b/src/liballoc/tests/rc.rs
index 0f618d1f9e6d8..876da79d350d4 100644
--- a/src/liballoc/tests/rc.rs
+++ b/src/liballoc/tests/rc.rs
@@ -98,5 +98,7 @@ fn eq() {
 
 #[test]
 fn to_nonnull() {
-    let _: std::ptr::NonNull<i32> = Rc::new(0).into();
+    let ptr: std::ptr::NonNull<i32> = Rc::new(0).into();
+    let deref = unsafe { *ptr.as_ref() };
+    assert_eq!(deref, 0);
 }

From 98b46ba2132e0fef721c0b5ef6c1933c44df310e Mon Sep 17 00:00:00 2001
From: Dale Wijnand <dale.wijnand@gmail.com>
Date: Sun, 23 Dec 2018 21:46:36 +0000
Subject: [PATCH 3/3] Add an Into<NonNull<T>> impl for Box<T>

---
 src/liballoc/boxed.rs      | 9 +++++++++
 src/liballoc/boxed_test.rs | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index 83adcce5c742c..40baf59b42ded 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -479,6 +479,15 @@ impl From<Box<str>> for Box<[u8]> {
     }
 }
 
+#[allow(incoherent_fundamental_impls)]
+#[unstable(feature = "box_into_raw_non_null", issue = "47336")]
+impl<T: ?Sized> Into<NonNull<T>> for Box<T> {
+    #[inline]
+    fn into(self) -> NonNull<T> {
+        Box::into_unique(self).into()
+    }
+}
+
 impl Box<dyn Any> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/liballoc/boxed_test.rs b/src/liballoc/boxed_test.rs
index f340ea01c5f07..26a5de121c393 100644
--- a/src/liballoc/boxed_test.rs
+++ b/src/liballoc/boxed_test.rs
@@ -148,3 +148,11 @@ fn boxed_slice_from_iter() {
     assert_eq!(boxed.len(), 100);
     assert_eq!(boxed[7], 7);
 }
+
+#[test]
+fn to_nonnull() {
+    let boxed: Box<i32> = Box::from(0);
+    let ptr: std::ptr::NonNull<i32> = boxed.into();
+    let deref = unsafe { *ptr.as_ref() };
+    assert_eq!(deref, 0);
+}