Remove UnsafeCoerce

Undefined behavior, broken for .NET 8

See: dotnet/runtime#102338

src/Aardvark.Base/Extensions/UnsafeCoerce.cs

@@ -2,7 +2,6 @@
 using System.Collections.Concurrent;
 using System.Reflection;
 using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
 
 namespace Aardvark.Base
 {
@@ -23,101 +22,5 @@ public static int GetCLRSize(this Type t)
                 return (int)mi.Invoke(null, null);
             });
         }
-
-        #region UnsafeCoerce
-
-        [Obsolete("breaks net8.0+")]
-        public static IntPtr GetTypeIdUncached<T>()
-            where T : struct
-        {
-            var gcHandle = GCHandle.Alloc(new T[1], GCHandleType.Pinned);
-            var typeField = gcHandle.AddrOfPinnedObject() - 2 * IntPtr.Size;
-            var typeId = Marshal.ReadIntPtr(typeField);
-            gcHandle.Free();
-            return typeId;
-        }
-
-        private static readonly FastConcurrentDict<Type, IntPtr> s_typeIds = new FastConcurrentDict<Type, IntPtr>();
-
-        [Obsolete("breaks net8.0+")]
-        private static IntPtr GetTypeId<T>()
-            where T : struct
-        {
-            if (!s_typeIds.TryGetValue(typeof(T), out IntPtr typeId))
-            {
-                typeId = GetTypeIdUncached<T>();
-                s_typeIds[typeof(T)] = typeId;
-            }
-            return typeId;
-        }
-
-        [Obsolete("breaks net8.0+")]
-        internal static TR[] UnsafeCoerce<TR>(this Array input, IntPtr targetId)
-            where TR : struct
-        {
-            var inputSize = GetCLRSize(input.GetType().GetElementType());
-            var outputSize = GetCLRSize(typeof(TR));
-            var newLength = (input.Length * inputSize) / outputSize;
-
-            var gcHandle = GCHandle.Alloc(input, GCHandleType.Pinned);
-            IntPtr baseAddress = gcHandle.AddrOfPinnedObject();
-            var sizeField = baseAddress - IntPtr.Size;
-            var typeField = sizeField - IntPtr.Size;
-
-            Marshal.WriteIntPtr(sizeField, (IntPtr)newLength);
-            Marshal.WriteIntPtr(typeField, targetId);
-
-            gcHandle.Free();
-
-            return (TR[])(object)input;
-        }
-
-        /// <summary>
-        /// Reinterprets an array as one of a different type
-        /// Both types must be structs and you may cause memory leaks when the array-byte-sizes are not multiple of each other
-        /// WARNING: destroys the original array
-        /// </summary>
-        [Obsolete("breaks net8.0+")]
-        public static TR[] UnsafeCoerce<TR>(this Array input)
-            where TR : struct
-        {
-            return UnsafeCoerce<TR>(input, GetTypeId<TR>());
-        }
-
-        [Obsolete("breaks net8.0+")]
-        internal static void UnsafeCoercedApply<TR>(this Array input, Action<TR[]> action, IntPtr targetId)
-            where TR : struct
-        {
-            var inputSize = GetCLRSize(input.GetType().GetElementType());
-            var outputSize = GetCLRSize(typeof(TR));
-            var originalLength = input.Length;
-            var targetLength = (originalLength * inputSize) / outputSize;
-
-            var gcHandle = GCHandle.Alloc(input, GCHandleType.Pinned);
-            IntPtr baseAddress = gcHandle.AddrOfPinnedObject();
-            var sizeField = baseAddress - IntPtr.Size;
-            var typeField = sizeField - IntPtr.Size;
-
-            var originalId = Marshal.ReadIntPtr(typeField);
-
-            Marshal.WriteIntPtr(typeField, targetId);
-            Marshal.WriteIntPtr(sizeField, (IntPtr)targetLength);
-
-            action((TR[])(object)input);
-
-            Marshal.WriteIntPtr(typeField, originalId);
-            Marshal.WriteIntPtr(sizeField, (IntPtr)originalLength);
-
-            gcHandle.Free();
-        }
-
-        [Obsolete("breaks net8.0+")]
-        public static void UnsafeCoercedApply<TR>(this Array input, Action<TR[]> action)
-            where TR : struct
-        {
-            UnsafeCoercedApply(input, action, GetTypeId<TR>());
-        }
-
-        #endregion
     }
 }