Maybe Monad C# implementation

Maybe.cs

using System;
using System.Collections;
using System.Collections.Generic;

namespace Utilities
{
    public static class Maybe
    {
        public static Maybe<T> From<T>(T value) => new Maybe<T>(value);
        public static Maybe<T> None<T>() => default(Maybe<T>);
    }
    
    public struct Maybe<T> : IEnumerable<T>
    {
        readonly bool _hasValue;
        public bool HasValue => _hasValue;

        readonly T _value;
        public T Value
        {
            get
            {
                if (!_hasValue)
                {
                    throw new InvalidOperationException();
                }
                return _value;
            }
        }

        internal Maybe(T value)
        {
            _hasValue = !ReferenceEquals(value, null);
            _value = value;
        }

        public static implicit operator Maybe<T>(T value) => new Maybe<T>(value);

        public IEnumerator<T> GetEnumerator()
        {
            if (_hasValue)
            {
                yield return _value;
            }
            yield break;
        }

        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
    }
}