using System;

using System.Runtime.InteropServices;

public class Program

{

    public static void Main()

    {

        var accessor = new TestProperty() {IsConfirmation = true};

        var wrappedValue = new Value(true);

        bool? metaValue = (bool?)wrappedValue;

        bool result = true;

        Console.WriteLine(accessor.IsConfirmation);

        Console.WriteLine(metaValue.Value);

        if (accessor.IsConfirmation != metaValue.Value)

        {

            Console.WriteLine($"Shouldn't get here {accessor.IsConfirmation} != {metaValue.Value}");

            result = false;

        }

​

        if (!result)

        {

            Console.WriteLine("What happened?") ;

        }

        else

        {

            Console.WriteLine("Worked as expected");

        }           

    }

    struct Value

    {

        public Value(bool initial)

        {

            _data.BooleanField = initial;

            // If you comment out this line it will work as expected

            _data.GuidField = new Guid("7cb8a2c8-4bb7-4374-94b2-c9232d20ec46");

        }

        UnionOfStuff _data;

        public static explicit operator bool?(Value valueToCast)

        {

            return valueToCast._data.BooleanField;

        }

    }

    [StructLayout(LayoutKind.Explicit)]

    struct UnionOfStuff

    {

        [FieldOffset(0)]

        public bool BooleanField;

        [FieldOffset(0)]

        public Guid GuidField;

    }

    class TestProperty

    {

        public bool IsConfirmation;

    }

}