From 85d9a06a62d73776b2fe7786e2d50e2833384331 Mon Sep 17 00:00:00 2001
From: bluss <bluss@users.noreply.github.com>
Date: Sat, 22 Dec 2018 14:25:16 +0100
Subject: [PATCH 1/3] FIX: Use repr(C) MaybeUninit after discussion with
 RalfJung

We have a recommendation from the unsafe-wg (no rule yet), that
repr(C) for unions should work this way, so that we can cast from the
union type to one of its fields.
---
 src/maybe_uninit.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/maybe_uninit.rs b/src/maybe_uninit.rs
index 71ec8f0..39c6366 100644
--- a/src/maybe_uninit.rs
+++ b/src/maybe_uninit.rs
@@ -7,6 +7,7 @@ use std::mem::ManuallyDrop;
 /// this wraps a value that can be wholly or partially uninitialized;
 /// it also has no drop regardless of the type of T.
 #[derive(Copy)]
+#[repr(C)] // for cast from self ptr to value
 pub union MaybeUninit<T> {
     empty: (),
     value: ManuallyDrop<T>,

From 06930d27ce8e292755754b1e09901fb36cd46919 Mon Sep 17 00:00:00 2001
From: bluss <bluss@users.noreply.github.com>
Date: Sat, 22 Dec 2018 19:59:32 +0100
Subject: [PATCH 2/3] FIX: Remove unused Copy/Clone for MaybeUninit

---
 src/maybe_uninit.rs | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/src/maybe_uninit.rs b/src/maybe_uninit.rs
index 39c6366..9ed1f6a 100644
--- a/src/maybe_uninit.rs
+++ b/src/maybe_uninit.rs
@@ -6,7 +6,6 @@ use std::mem::ManuallyDrop;
 /// A combination of ManuallyDrop and “maybe uninitialized”;
 /// this wraps a value that can be wholly or partially uninitialized;
 /// it also has no drop regardless of the type of T.
-#[derive(Copy)]
 #[repr(C)] // for cast from self ptr to value
 pub union MaybeUninit<T> {
     empty: (),
@@ -14,11 +13,6 @@ pub union MaybeUninit<T> {
 }
 // Why we don't use std's MaybeUninit on nightly? See the ptr method
 
-impl<T> Clone for MaybeUninit<T> where T: Copy
-{
-    fn clone(&self) -> Self { *self }
-}
-
 impl<T> MaybeUninit<T> {
     /// Create a new MaybeUninit with uninitialized interior
     pub unsafe fn uninitialized() -> Self {

From 21661facf8f5d65b4bd6701e48d218eb957314fa Mon Sep 17 00:00:00 2001
From: bluss <bluss@users.noreply.github.com>
Date: Sat, 22 Dec 2018 20:04:03 +0100
Subject: [PATCH 3/3] 0.4.10

---
 Cargo.toml | 2 +-
 README.rst | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index 61a61ce..4dd9697 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "arrayvec"
-version = "0.4.9"
+version = "0.4.10"
 authors = ["bluss"]
 license = "MIT/Apache-2.0"
 
diff --git a/README.rst b/README.rst
index 29d3a2f..4af5330 100644
--- a/README.rst
+++ b/README.rst
@@ -22,6 +22,11 @@ __ https://docs.rs/arrayvec
 Recent Changes (arrayvec)
 -------------------------
 
+- 0.4.10
+
+  - Use ``repr(C)`` in the ``union`` version that was introduced in 0.4.9, to
+    allay some soundness concerns.
+
 - 0.4.9
 
   - Use ``union`` in the implementation on when this is detected to be supported