dotnet-core/release-notes/2.1/Preview/api-diff/preview1/2.1-preview1_System.Runtime.Intrinsics.md

System.Runtime.Intrinsics

+namespace System.Runtime.Intrinsics {
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, Size=16)]
+    public struct Vector128<T> where T : struct
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, Size=32)]
+    public struct Vector256<T> where T : struct
+}