public class Maybe<T>
{
    private readonly T value;

    private Maybe(bool hasValue, T value) : this(hasValue) => this.value = value;

    private Maybe(bool hasValue) => HasValue = hasValue;

    public bool HasValue {get;}

    public T Value => HasValue ? value : throw new InvalidOperationException();

    public static Maybe<T> None {get;} = new Maybe<T>(false);

    public static Maybe<T> Some(T value) => new Maybe<T>(true, value);

    public Maybe<U> Bind<U>(Func<T, Maybe<U>> f) => HasValue ? f(value) : Maybe<U>.None;
}

var client = Maybe<int>.Some(1)
    .Bind(orderId => GetOrder(orderId))
    .Bind(order => GetClient(order.ClientId));
Console.WriteLine(client);

var client = Maybe<int>.Some(1)
    .Bind(orderId => GetOrderAsync(orderId))
    .Bind(order => GetClientAsync(order.ClientId));
Console.WriteLine(client);

public Maybe<U> Bind<U>(Func<T, Task<Maybe<U>>> f)
    => HasValue ? f(value).Result : Maybe<U>.None;

public async Task<Maybe<U>> Bind<U>(Func<T, Task<Maybe<U>>> f)
    => HasValue ? await f(value) : Maybe<U>.None;

var asyncClient = await (await 2.ToMaybe()
    .Bind(orderId => GetOrderAsync(orderId)))
    .Bind(order => GetClientAsync(order.ClientId));