Option.cs

using System;

namespace Option
{
    public class Option<T>
    {
        private readonly T _value;
        private readonly bool _hasValue;

        private Option(T value, bool hasValue)
        {
            _value = value;
            _hasValue = hasValue;
        }
        public static Option<T> None()
        {
            return new Option<T>(default(T), false);
        }
        public static Option<T> Some(T value)
        {
            if (value == null) return None();
            return new Option<T>(value, true);
        }
        public void PerformAction(Action<T> ifSome, Action ifNone)
        {
            if (_hasValue)
                ifSome(_value);
            else
                ifNone();
        }
        public U Map<U>(Func<T, U> ifSome, Func<U> ifNone)
        {
            return _hasValue ? ifSome(_value) : ifNone();
        }
    }
}

// Example Usage

    class Program
    {
        static void Main(string[] args)
        {
            var result = Divide(4, 0);
            result.PerformAction(Console.WriteLine, () => Console.WriteLine("Failed to parse"));

            result = Divide(4, 2);
            result.PerformAction(Console.WriteLine, () => Console.WriteLine("Failed to parse."));

            var mappedResult = result.Map(x => x, () => 0);
            Console.WriteLine("Result is " + mappedResult);
        }

        private static Option<int> Divide(int a, int b)
        {
            return b == 0 ? Option<int>.None() : Option<int>.Some(a/b);
        }
    }