Port more things!

Myriad/Utils/Optional.cs

@@ -0,0 +1,32 @@
+using System.Text.Json.Serialization;
+
+using Myriad.Serialization;
+
+namespace Myriad.Utils
+{
+    public interface IOptional
+    {
+        bool HasValue { get; }
+        object? GetValue();
+    }
+    
+    [JsonConverter(typeof(OptionalConverter))]
+    public readonly struct Optional<T>: IOptional
+    {
+        public Optional(T value)
+        {
+            HasValue = true;
+            Value = value;
+        }
+
+        public bool HasValue { get; }
+        public object? GetValue() => Value;
+
+        public T Value { get; }
+
+        public static implicit operator Optional<T>(T value) => new(value);
+
+        public static Optional<T> Some(T value) => new(value);
+        public static Optional<T> None() => default;
+    }
+}