fixes and adjustments

Railway/ReflectionHelper.cs

@@ -4,9 +4,22 @@ namespace Just.Railway;
 
 internal static class ReflectionHelper
 {
+    [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static R ObjectCast<R>(object value) where R: class => (R)value;
+
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool IsEqual<T>(T? left, T? right) => TypeReflectionCache<T>.IsEqualFunc(left, right);
 
+    [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
+    /// <summary>
+    /// Test for potential nullability
+    /// </summary>
+    /// <returns>true if T is reference type or Nullable value type.</returns>
+    public static bool IsNullable<T>() => TypeReflectionCache<T>.IsNullable;
+
+    [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsNullableStruct<T>() => TypeReflectionCache<T>.IsNullableStruct;
+
     private static class TypeReflectionCache<T>
     {
         public static readonly Func<T?, T?, bool> IsEqualFunc;
@@ -30,8 +43,14 @@ internal static class ReflectionHelper
             {
                 IsEqualFunc = static (left, right) => left is null ? right is null : left.Equals(right);
             }
+
+            IsNullableStruct = isNullableStruct;
+            IsNullable = isNullableStruct || !type.IsValueType;
         }
 
+        public static bool IsNullable { get; }
+        public static bool IsNullableStruct { get; }
+
     #pragma warning disable CS8604 // Possible null reference argument.
         [Pure] public static bool IsEqual<R>(R? left, R? right) where R : notnull, IEquatable<R>, T => left is null ? right is null : left.Equals(right);
         [Pure] public static bool IsEqualNullable<R>(R? left, R? right) where R : struct, IEquatable<R> => left is null ? right is null : right is not null && left.Value.Equals(right.Value);