From 35bd79548c0ef1b61f7de96d2abda2343315d2e3 Mon Sep 17 00:00:00 2001
From: ahsonkhan <ahson_ahmedk@yahoo.com>
Date: Mon, 25 Sep 2017 17:01:03 -0700
Subject: [PATCH] Making Memory and ReadOnly readonly, fixing issue #23809

---
 src/System.Memory/ref/System.Memory.cs         | 4 ++--
 src/System.Memory/src/System/Memory.cs         | 2 +-
 src/System.Memory/src/System/ReadOnlyMemory.cs | 2 +-
 src/System.Runtime/ref/System.Runtime.cs       | 4 ++--
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/System.Memory/ref/System.Memory.cs b/src/System.Memory/ref/System.Memory.cs
index ee6ecea323e4..04b521e293fc 100644
--- a/src/System.Memory/ref/System.Memory.cs
+++ b/src/System.Memory/ref/System.Memory.cs
@@ -123,7 +123,7 @@ public static class SpanExtensions
         public static ReadOnlySpan<TTo> NonPortableCast<TFrom, TTo>(this ReadOnlySpan<TFrom> source) where TFrom : struct where TTo : struct { throw null; }
     }
 
-    public struct ReadOnlyMemory<T>
+    public readonly struct ReadOnlyMemory<T>
     {
         public static ReadOnlyMemory<T> Empty { get { throw null; } }
         public ReadOnlyMemory(T[] array) { throw null;}
@@ -147,7 +147,7 @@ public struct ReadOnlyMemory<T>
         public bool DangerousTryGetArray(out ArraySegment<T> arraySegment) { throw null; }
     }
 
-    public struct Memory<T>
+    public readonly struct Memory<T>
     {
         public static Memory<T> Empty { get { throw null; } }
         public Memory(T[] array) { throw null;}
diff --git a/src/System.Memory/src/System/Memory.cs b/src/System.Memory/src/System/Memory.cs
index a71fc76fb2ed..c5779b70ad7a 100644
--- a/src/System.Memory/src/System/Memory.cs
+++ b/src/System.Memory/src/System/Memory.cs
@@ -16,7 +16,7 @@ namespace System
     /// Memory represents a contiguous region of arbitrary memory similar to Span.
     /// Unlike Span, it is not a byref-like type.
     /// </summary>
-    public struct Memory<T>
+    public readonly struct Memory<T>
     {
         // The highest order bit of _index is used to discern whether _arrayOrOwnedMemory is an array or an owned memory
         // if (_index >> 31) == 1, object _arrayOrOwnedMemory is an OwnedMemory<T>
diff --git a/src/System.Memory/src/System/ReadOnlyMemory.cs b/src/System.Memory/src/System/ReadOnlyMemory.cs
index 5d5e3bd78efc..5d901c518e00 100644
--- a/src/System.Memory/src/System/ReadOnlyMemory.cs
+++ b/src/System.Memory/src/System/ReadOnlyMemory.cs
@@ -16,7 +16,7 @@ namespace System
     /// ReadOnlyMemory represents a contiguous region of arbitrary similar to ReadOnlySpan.
     /// Unlike ReadOnlySpan, it is not a byref-like type.
     /// </summary>
-    public struct ReadOnlyMemory<T>
+    public readonly struct ReadOnlyMemory<T>
     {
         // The highest order bit of _index is used to discern whether _arrayOrOwnedMemory is an array or an owned memory
         // if (_index >> 31) == 1, object _arrayOrOwnedMemory is an OwnedMemory<T>
diff --git a/src/System.Runtime/ref/System.Runtime.cs b/src/System.Runtime/ref/System.Runtime.cs
index fbd1c2cbdd91..a8cf195db662 100644
--- a/src/System.Runtime/ref/System.Runtime.cs
+++ b/src/System.Runtime/ref/System.Runtime.cs
@@ -1637,7 +1637,7 @@ public MemberAccessException(string message) { }
         public MemberAccessException(string message, System.Exception inner) { }
         protected MemberAccessException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) : base(info, context) { }
     }
-    public struct Memory<T>
+    public readonly struct Memory<T>
     {
         public static Memory<T> Empty { get { throw null; } }
         public Memory(T[] array) { throw null;}
@@ -1861,7 +1861,7 @@ public RankException(string message) { }
         public RankException(string message, System.Exception innerException) { }
         protected RankException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) : base(info, context) { }
     }
-    public struct ReadOnlyMemory<T>
+    public readonly struct ReadOnlyMemory<T>
     {
         public static ReadOnlyMemory<T> Empty { get { throw null; } }
         public ReadOnlyMemory(T[] array) { throw null;}