From ff53c39a85a16d35dcab6ce5249b02e86f4b76a3 Mon Sep 17 00:00:00 2001
From: Aaron Robinson <arobins@microsoft.com>
Date: Sun, 23 Jan 2022 08:11:18 -0800
Subject: [PATCH 1/3] Add ref field runtime feature indication

---
 .../src/System/Runtime/CompilerServices/RuntimeFeature.cs   | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs
index a94a0e19d01761..b4be9135e477b8 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs
@@ -27,6 +27,11 @@ public static partial class RuntimeFeature
         /// </summary>
         public const string CovariantReturnsOfClasses = nameof(CovariantReturnsOfClasses);
 
+        /// <summary>
+        /// Indicates that this version of runtime supports ref fields.
+        /// </summary>
+        public const string RefFields = nameof(RefFields);
+
         /// <summary>
         /// Indicates that this version of runtime supports virtual static members of interfaces.
         /// </summary>
@@ -42,6 +47,7 @@ public static bool IsSupported(string feature)
             {
                 case PortablePdb:
                 case CovariantReturnsOfClasses:
+                case RefFields:
                 case UnmanagedSignatureCallingConvention:
                 case DefaultImplementationsOfInterfaces:
 #pragma warning disable CA2252

From 857f4285852e0f403b3c3a0848992092e7016dfc Mon Sep 17 00:00:00 2001
From: Aaron Robinson <arobins@microsoft.com>
Date: Sun, 23 Jan 2022 09:00:09 -0800
Subject: [PATCH 2/3] Change name to follow existing pattern for ByRef
 concepts. Add new field to ref assembly

---
 .../src/System/Runtime/CompilerServices/RuntimeFeature.cs     | 4 ++--
 src/libraries/System.Runtime/ref/System.Runtime.cs            | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs
index b4be9135e477b8..a1c581f60f57dd 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs
@@ -30,7 +30,7 @@ public static partial class RuntimeFeature
         /// <summary>
         /// Indicates that this version of runtime supports ref fields.
         /// </summary>
-        public const string RefFields = nameof(RefFields);
+        public const string ByRefFields = nameof(ByRefFields);
 
         /// <summary>
         /// Indicates that this version of runtime supports virtual static members of interfaces.
@@ -47,7 +47,7 @@ public static bool IsSupported(string feature)
             {
                 case PortablePdb:
                 case CovariantReturnsOfClasses:
-                case RefFields:
+                case ByRefFields:
                 case UnmanagedSignatureCallingConvention:
                 case DefaultImplementationsOfInterfaces:
 #pragma warning disable CA2252
diff --git a/src/libraries/System.Runtime/ref/System.Runtime.cs b/src/libraries/System.Runtime/ref/System.Runtime.cs
index c57c5b13cc1190..8006340a876657 100644
--- a/src/libraries/System.Runtime/ref/System.Runtime.cs
+++ b/src/libraries/System.Runtime/ref/System.Runtime.cs
@@ -13206,6 +13206,7 @@ public RuntimeCompatibilityAttribute() { }
     }
     public static partial class RuntimeFeature
     {
+        public const string ByRefFields = "ByRefFields";
         public const string CovariantReturnsOfClasses = "CovariantReturnsOfClasses";
         public const string DefaultImplementationsOfInterfaces = "DefaultImplementationsOfInterfaces";
         public const string PortablePdb = "PortablePdb";

From 3193560092d65357c5d28fc9f0c54a1fc1731a1d Mon Sep 17 00:00:00 2001
From: Aaron Robinson <arobins@microsoft.com>
Date: Mon, 24 Jan 2022 10:27:52 -0500
Subject: [PATCH 3/3] Update
 src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs

Co-authored-by: Stephen Toub <stoub@microsoft.com>
---
 .../src/System/Runtime/CompilerServices/RuntimeFeature.cs       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs
index a1c581f60f57dd..9e0a5ed29e42e8 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs
@@ -28,7 +28,7 @@ public static partial class RuntimeFeature
         public const string CovariantReturnsOfClasses = nameof(CovariantReturnsOfClasses);
 
         /// <summary>
-        /// Indicates that this version of runtime supports ref fields.
+        /// Represents a runtime feature where types can define ref fields.
         /// </summary>
         public const string ByRefFields = nameof(ByRefFields);