Added SpanExtensions and the reinterpret between Unity's structs to System.Numerics structs

X10D.Unity/src/Numerics/QuaternionExtensions.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics.Contracts;
 using System.Runtime.CompilerServices;
+using Unity.Collections.LowLevel.Unsafe;
 using UnityEngine;
 
 namespace X10D.Unity.Numerics;
@@ -18,7 +19,7 @@ public static class QuaternionExtensions
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static System.Numerics.Quaternion ToSystemQuaternion(this Quaternion quaternion)
     {
-        return new System.Numerics.Quaternion(quaternion.x, quaternion.y, quaternion.z, quaternion.w);
+        return UnsafeUtility.As<Quaternion, System.Numerics.Quaternion>(ref quaternion);
     }
 
     /// <summary>
@@ -30,6 +31,6 @@ public static class QuaternionExtensions
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Quaternion ToUnityQuaternion(this System.Numerics.Quaternion quaternion)
     {
-        return new Quaternion(quaternion.X, quaternion.Y, quaternion.Z, quaternion.W);
+        return UnsafeUtility.As<System.Numerics.Quaternion, Quaternion>(ref quaternion);
     }
 }

X10D.Unity/src/Numerics/Vector2Extensions.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics.Contracts;
 using System.Runtime.CompilerServices;
+using Unity.Collections.LowLevel.Unsafe;
 using UnityEngine;
 
 namespace X10D.Unity.Numerics;
@@ -18,7 +19,7 @@ public static class Vector2Extensions
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static System.Numerics.Vector2 ToSystemVector(this Vector2 vector)
     {
-        return new System.Numerics.Vector2(vector.x, vector.y);
+        return UnsafeUtility.As<Vector2, System.Numerics.Vector2>(ref vector);
     }
 
     /// <summary>
@@ -30,7 +31,7 @@ public static class Vector2Extensions
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Vector2 ToUnityVector(this System.Numerics.Vector2 vector)
     {
-        return new Vector2(vector.X, vector.Y);
+        return UnsafeUtility.As<System.Numerics.Vector2, Vector2>(ref vector);
     }
 
     /// <summary>

X10D.Unity/src/Numerics/Vector3Extensions.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics.Contracts;
 using System.Runtime.CompilerServices;
+using Unity.Collections.LowLevel.Unsafe;
 using UnityEngine;
 
 namespace X10D.Unity.Numerics;
@@ -18,7 +19,7 @@ public static class Vector3Extensions
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static System.Numerics.Vector3 ToSystemVector(this Vector3 vector)
     {
-        return new System.Numerics.Vector3(vector.x, vector.y, vector.z);
+        return UnsafeUtility.As<Vector3, System.Numerics.Vector3>(ref vector);
     }
 
     /// <summary>
@@ -30,7 +31,7 @@ public static class Vector3Extensions
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Vector3 ToUnityVector(this System.Numerics.Vector3 vector)
     {
-        return new Vector3(vector.X, vector.Y, vector.Z);
+        return UnsafeUtility.As<System.Numerics.Vector3, Vector3>(ref vector);
     }
 
     /// <summary>

X10D.Unity/src/Numerics/Vector4Extensions.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics.Contracts;
 using System.Runtime.CompilerServices;
+using Unity.Collections.LowLevel.Unsafe;
 using UnityEngine;
 
 namespace X10D.Unity.Numerics;
@@ -18,7 +19,8 @@ public static class Vector4Extensions
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static System.Numerics.Vector4 ToSystemVector(this Vector4 vector)
     {
-        return new System.Numerics.Vector4(vector.x, vector.y, vector.z, vector.w);
+        return UnsafeUtility.As<Vector4, System.Numerics.Vector4>(ref vector);
+
     }
 
     /// <summary>
@@ -30,7 +32,7 @@ public static class Vector4Extensions
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Vector4 ToUnityVector(this System.Numerics.Vector4 vector)
     {
-        return new Vector4(vector.X, vector.Y, vector.Z, vector.W);
+        return UnsafeUtility.As<System.Numerics.Vector4, Vector4>(ref vector);
     }
 
     /// <summary>

X10D/src/Collections/Int32Extensions.cs

@@ -110,6 +110,7 @@ public static class Int32Extensions
                 and = Sse2.AndNot(shuffle, mask2);
                 cmp = Sse2.CompareEqual(and, Vector128<byte>.Zero);
                 correctness = Sse2.And(cmp, one);
+
                 Sse2.Store((byte*)pDestination + 16, correctness);
             }
         }

X10D/src/Core/SpanExtensions.cs

@@ -0,0 +1,89 @@
+using System.Diagnostics.Contracts;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace X10D.Core;
+
+/// <summary>
+/// Extension methods for <see cref="Span{T}"/> and <see cref="ReadOnlySpan{T}"/>.
+/// </summary>
+public static class SpanExtensions
+{
+    /// <summary>
+    ///     Indicate whether a specific enumeration value is found in a span.
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    /// <param name="span">The span to search from.</param>
+    /// <param name="value">The enum to search for.</param>
+    /// <returns><see langword="true"/> if found, <see langword="false"/> otherwise.</returns>
+    /// <exception cref="ArgumentException">Unexpected enum memory size.</exception>
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static bool Contains<T>(this Span<T> span, T value) where T : Enum
+    {
+        return Contains((ReadOnlySpan<T>)span, value);
+    }
+
+    /// <summary>
+    ///     Indicate whether a specific enumeration value is found in a span.
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    /// <param name="span">The span to search from.</param>
+    /// <param name="value">The enum to search for.</param>
+    /// <returns><see langword="true"/> if found, <see langword="false"/> otherwise.</returns>
+    /// <exception cref="ArgumentException">Unexpected enum memory size.</exception>
+#if NETSTANDARD2_1
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#else
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+#endif
+    public static bool Contains<T>(this ReadOnlySpan<T> span, T value)
+    {
+        // Use MemoryMarshal.CreateSpan instead of using creating new Span instance from pointer will trim down a lot of instructions
+        // on Release mode.
+        // https://sharplab.io/#v2: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=
+
+        // TODO: Figure out some kind of way to directly pass the Span directly into Contains call, which make method smaller and more prone to inlining...
+        unsafe
+        {
+#pragma warning disable CS8500 // This takes the address of, gets the size of, or declares a pointer to a managed type
+            switch (sizeof(T))
+            {
+                case 1:
+                    {
+                        ref byte enums = ref Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(span));
+                        return MemoryMarshal.CreateSpan(ref enums, span.Length).Contains(Unsafe.As<T, byte>(ref value));
+                    }
+
+                case 2:
+                    {
+                        ref ushort enums = ref Unsafe.As<T, ushort>(ref MemoryMarshal.GetReference(span));
+                        return MemoryMarshal.CreateSpan(ref enums, span.Length).Contains(Unsafe.As<T, ushort>(ref value));
+                    }
+
+                case 4:
+                    {
+                        ref uint enums = ref Unsafe.As<T, uint>(ref MemoryMarshal.GetReference(span));
+                        return MemoryMarshal.CreateSpan(ref enums, span.Length).Contains(Unsafe.As<T, uint>(ref value));
+                    }
+
+                case 8:
+                    {
+                        ref ulong enums = ref Unsafe.As<T, ulong>(ref MemoryMarshal.GetReference(span));
+                        return MemoryMarshal.CreateSpan(ref enums, span.Length).Contains(Unsafe.As<T, ulong>(ref value));
+                    }
+
+                default:
+#if NET7_0_OR_GREATER
+                    throw new UnreachableException($"Enum with the size of {Unsafe.SizeOf<T>()} bytes is unexpected.");
+#else
+                    throw new ArgumentException($"Enum with the size of {Unsafe.SizeOf<T>()} bytes is unexpected.");
+#endif
+            }
+#pragma warning restore CS8500 // This takes the address of, gets the size of, or declares a pointer to a managed type
+        }
+    }
+}