From 47e43327864de3c5e85cae390f0c3ee3ef6b5889 Mon Sep 17 00:00:00 2001
From: Sergio Pedri <sergio0694@live.com>
Date: Sat, 13 Jan 2024 17:46:16 +0100
Subject: [PATCH] Cache enum stubs and further avoid display classes

---
 src/WinRT.Runtime/Marshalers.cs | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/WinRT.Runtime/Marshalers.cs b/src/WinRT.Runtime/Marshalers.cs
index 7d0989fce..c1f392d57 100644
--- a/src/WinRT.Runtime/Marshalers.cs
+++ b/src/WinRT.Runtime/Marshalers.cs
@@ -1672,16 +1672,24 @@ public static T FromAbi<T>(IntPtr nativeDelegate)
 
     internal static class Marshaler
     {
-        internal static Action<object> EmptyFunc = (object box) => { };
-        internal static Func<object, object> ReturnParameterFunc = (object box) => box;
+        internal static readonly Action<object> EmptyFunc = Empty;
+        internal static readonly Func<object, object> ReturnParameterFunc = ReturnParameter;
+        internal static readonly Action<object, IntPtr> CopyIntEnumFunc = CopyIntEnum;
+        internal static readonly Action<object, IntPtr> CopyIntEnumDirectFunc = CopyIntEnumDirect;
+        internal static readonly Action<object, IntPtr> CopyUIntEnumFunc = CopyUIntEnum;
+        internal static readonly Action<object, IntPtr> CopyUIntEnumDirectFunc = CopyUIntEnumDirect;
 
-        internal static unsafe void CopyIntEnum(object value, IntPtr dest) => *(int*)dest.ToPointer() = (int)Convert.ChangeType(value, typeof(int));
+        private static void Empty(object arg) { }
 
-        internal static unsafe void CopyIntEnumDirect(object value, IntPtr dest) => *(int*)dest.ToPointer() = (int)value;
+        private static object ReturnParameter(object arg) => arg;
 
-        internal static unsafe void CopyUIntEnum(object value, IntPtr dest) => *(uint*)dest.ToPointer() = (uint)Convert.ChangeType(value, typeof(uint));
+        private static unsafe void CopyIntEnum(object value, IntPtr dest) => *(int*)dest.ToPointer() = (int)Convert.ChangeType(value, typeof(int));
 
-        internal static unsafe void CopyUIntEnumDirect(object value, IntPtr dest) => *(uint*)dest.ToPointer() = (uint)value;
+        private static unsafe void CopyIntEnumDirect(object value, IntPtr dest) => *(int*)dest.ToPointer() = (int)value;
+
+        private static unsafe void CopyUIntEnum(object value, IntPtr dest) => *(uint*)dest.ToPointer() = (uint)Convert.ChangeType(value, typeof(uint));
+
+        private static unsafe void CopyUIntEnumDirect(object value, IntPtr dest) => *(uint*)dest.ToPointer() = (uint)value;
     }
 
 #if EMBED
@@ -1842,13 +1850,13 @@ static Marshaler()
                         // For marshaling non-blittable enum arrays via MarshalNonBlittable
                         if (typeof(T).GetEnumUnderlyingType() == typeof(int))
                         {
-                            CopyAbi = Marshaler.CopyIntEnum;
-                            CopyManaged = ((Action<object, IntPtr>)Marshaler.CopyIntEnumDirect).WithTypedEnumT1<T>();
+                            CopyAbi = Marshaler.CopyIntEnumFunc;
+                            CopyManaged = Marshaler.CopyIntEnumDirectFunc.WithTypedEnumT1<T>();
                         }
                         else
                         {
-                            CopyAbi = Marshaler.CopyUIntEnum;
-                            CopyManaged = ((Action<object, IntPtr>)Marshaler.CopyUIntEnumDirect).WithTypedEnumT1<T>();
+                            CopyAbi = Marshaler.CopyUIntEnumFunc;
+                            CopyManaged = Marshaler.CopyUIntEnumDirectFunc.WithTypedEnumT1<T>();
                         }
                     }
                     CreateMarshalerArray = (T[] array) => MarshalBlittable<T>.CreateMarshalerArray(array);