Optimize AdvancedEvent by using C/C++ union?

[DiscreteTom]

Ref: https://learn.microsoft.com/en-us/dotnet/csharp/advanced-topics/reflection-and-attributes/how-to-create-a-c-cpp-union-by-using-attributes

[DiscreteTom]

Explicit struct layout is not supported with generic types. Ref: https://stackoverflow.com/questions/26746189/why-cant-generic-types-have-explicit-layout

This will throw runtime error:

  [StructLayout(LayoutKind.Explicit)] // #35
  public struct ActionItem<T0> : IActionItem<T0> {
    [field: FieldOffset(0)]
    public AdvancedEventParamCount paramCount { get; set; }
    [field: FieldOffset(4)] // AdvancedEventParamCount's byte size is 4
    public UnityAction action0 { get; set; }
    [field: FieldOffset(4)] // AdvancedEventParamCount's byte size is 4
    public UnityAction<T0> action1 { get; set; }
  }