From ef519c1de54e6d833d05bac7c4ce290ae54e82dc Mon Sep 17 00:00:00 2001
From: Georg Semmler <georg_semmler_05@web.de>
Date: Thu, 9 Aug 2018 11:02:08 +0200
Subject: [PATCH 1/3] Add a implementation of `From` for converting `&'a
 Option<T>` into `Option<&'a T>`

---
 src/libcore/option.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 2b6c376f8a7..ad69d137685 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -1064,6 +1064,12 @@ impl<T> From<T> for Option<T> {
     }
 }
 
+impl<'a, T> From<&'a Option<T>> for Option<&'a T> {
+    fn from(o: &'a Option<T>) -> Option<&'a T> {
+        o.as_ref()
+    }
+}
+
 /////////////////////////////////////////////////////////////////////////////
 // The Option Iterators
 /////////////////////////////////////////////////////////////////////////////

From 0cde1cbb10b044c17e1569ab0306db11735ca798 Mon Sep 17 00:00:00 2001
From: Georg Semmler <georg_semmler_05@web.de>
Date: Thu, 9 Aug 2018 12:48:55 +0200
Subject: [PATCH 2/3] Add stability attribute

---
 src/libcore/option.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index ad69d137685..883e01ff2a8 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -1064,6 +1064,7 @@ impl<T> From<T> for Option<T> {
     }
 }
 
+#[stable(feature = "option_ref_from_ref_option", since = "1.30.0")]
 impl<'a, T> From<&'a Option<T>> for Option<&'a T> {
     fn from(o: &'a Option<T>) -> Option<&'a T> {
         o.as_ref()

From a7a0225a281bbb9306862e647aee2f51aa595086 Mon Sep 17 00:00:00 2001
From: Georg Semmler <georg_semmler_05@web.de>
Date: Fri, 10 Aug 2018 14:21:17 +0200
Subject: [PATCH 3/3] Also add a `From` implementation for `&mut Option<T>` ->
 `Option<&mut T>'

---
 src/libcore/option.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 883e01ff2a8..32a0a8b3c51 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -1071,6 +1071,13 @@ impl<'a, T> From<&'a Option<T>> for Option<&'a T> {
     }
 }
 
+#[stable(feature = "option_ref_from_ref_option", since = "1.30.0")]
+impl<'a, T> From<&'a mut Option<T>> for Option<&'a mut T> {
+    fn from(o: &'a mut Option<T>) -> Option<&'a mut T> {
+        o.as_mut()
+    }
+}
+
 /////////////////////////////////////////////////////////////////////////////
 // The Option Iterators
 /////////////////////////////////////////////////////////////////////////////