Add support for Flags, fix unsafe conversions

Author: gilzoide

Runtime/Commons.cs

@@ -1,5 +1,7 @@
 using System;
 using System.Collections.Generic;
+using System.Reflection;
+using System.Runtime.InteropServices;
 #if UNITY_5_3_OR_NEWER
 using Unity.Collections.LowLevel.Unsafe;
 #endif
@@ -71,6 +73,10 @@ public static int EnumToInt<T>(T value) where T : struct, Enum
 #if UNITY_5_3_OR_NEWER
             return UnsafeUtility.EnumToInt(value);
 #elif NETCOREAPP3_0_OR_GREATER || NET5_0_OR_GREATER
+            if (EnumMetadata<T>.SizeOf == sizeof(long))
+            {
+                return (int) Unsafe.As<T, long>(ref value);
+            }
             return Unsafe.As<T, int>(ref value);
 #else
             return Convert.ToInt32(value);
@@ -80,12 +86,68 @@ public static int EnumToInt<T>(T value) where T : struct, Enum
         public static T IntToEnum<T>(int value) where T : Enum
         {
 #if UNITY_5_3_OR_NEWER
+            if (EnumMetadata<T>.SizeOf == sizeof(long))
+            {
+                var longValue = (long) value;
+                return UnsafeUtility.As<long, T>(ref longValue);
+            }
             return UnsafeUtility.As<int, T>(ref value);
 #elif NETCOREAPP3_0_OR_GREATER || NET5_0_OR_GREATER
+            if (EnumMetadata<T>.SizeOf == sizeof(long))
+            {
+                var longValue = (long) value;
+                return Unsafe.As<long, T>(ref longValue);
+            }
             return Unsafe.As<int, T>(ref value);
 #else
             return (T) Enum.ToObject(typeof(T), value);
 #endif
         }
+
+        public static long EnumToLong<T>(T value) where T : struct, Enum
+        {
+#if UNITY_5_3_OR_NEWER
+            if (EnumMetadata<T>.SizeOf == sizeof(long))
+            {
+                return UnsafeUtility.As<T, long>(ref value);
+            }
+            return UnsafeUtility.EnumToInt(value);
+#elif NETCOREAPP3_0_OR_GREATER || NET5_0_OR_GREATER
+            if (EnumMetadata<T>.SizeOf == sizeof(long))
+            {
+                return Unsafe.As<T, long>(ref value);
+            }
+            return Unsafe.As<T, int>(ref value);
+#else
+            return Convert.ToInt64(value);
+#endif
+        }
+
+        public static T LongToEnum<T>(long value) where T : Enum
+        {
+#if UNITY_5_3_OR_NEWER
+            if (EnumMetadata<T>.SizeOf == sizeof(long))
+            {
+                return UnsafeUtility.As<long, T>(ref value);
+            }
+            var intValue = (int) value;
+            return UnsafeUtility.As<int, T>(ref intValue);
+#elif NETCOREAPP3_0_OR_GREATER || NET5_0_OR_GREATER
+            if (EnumMetadata<T>.SizeOf == sizeof(long))
+            {
+                return Unsafe.As<long, T>(ref value);
+            }
+            var intValue = (int) value;
+            return Unsafe.As<int, T>(ref intValue);
+#else
+            return (T) Enum.ToObject(typeof(T), value);
+#endif
+        }
+    }
+
+    public static class EnumMetadata<T> where T : Enum
+    {
+        public static int SizeOf = Marshal.SizeOf(Enum.GetUnderlyingType(typeof(T)));
+        public static bool HasFlags = typeof(T).IsDefined(typeof(FlagsAttribute));
     }
 }

Runtime/EnumBitMask32.cs

@@ -127,7 +127,8 @@ public IEnumerator<T> GetEnumerator()
         {
             foreach (var bitIndex in Commons.EnumerateSetBits(_data))
             {
-                yield return Commons.IntToEnum<T>(bitIndex);
+                var value = EnumMetadata<T>.HasFlags ? 1 << bitIndex : bitIndex;
+                yield return Commons.IntToEnum<T>(value);
             }
         }
 
@@ -149,6 +150,10 @@ public bool Equals(EnumBitMask32<T> other)
 
         private static int GetIntBitMask(T data)
         {
+            if (EnumMetadata<T>.HasFlags)
+            {
+                return Commons.EnumToInt(data);
+            }
             Contract.Requires(Commons.EnumToInt(data) < 32);
             return 1 << Commons.EnumToInt(data);
         }

Runtime/EnumBitMask64.cs

@@ -127,7 +127,8 @@ public IEnumerator<T> GetEnumerator()
         {
             foreach (var bitIndex in Commons.EnumerateSetBits(_data))
             {
-                yield return Commons.IntToEnum<T>(bitIndex);
+                var value = EnumMetadata<T>.HasFlags ? 1L << bitIndex : bitIndex;
+                yield return Commons.LongToEnum<T>(value);
             }
         }
 
@@ -149,6 +150,10 @@ public bool Equals(EnumBitMask64<T> other)
 
         private static long GetLongBitMask(T data)
         {
+            if (EnumMetadata<T>.HasFlags)
+            {
+                return Commons.EnumToLong(data);
+            }
             Contract.Requires(Commons.EnumToInt(data) < 64);
             return 1L << Commons.EnumToInt(data);
         }