非同期メソッドでTry-メソッドめいたものを使う

TaskExtensions.cs

using System.Threading.Tasks;

namespace Try
{
    public static class TaskExtensions
    {
        public static async Task<ITriable<T>> AsTriable<T>(this Task<T> task)
        {
            return await Triable<T>.ToTriableAsync(task);
        }
    }
}

Triable.cs

using System.Threading.Tasks;

namespace Try
{
    public interface ITriable<T>
    {
        bool TryGet(out T obj);
    }
    
    public class Triable<T> : ITriable<T>
    {
        private T _obj;

        public Triable(T obj)
        {
            _obj = obj;
        }

        public static async Task<ITriable<T>> ToTriableAsync(Task<T> task)
        {
            var result = await task;
            if (result == null)
                return new Nothing<T>();
            else
                return new Triable<T>(result);
        }

        public bool TryGet(out T obj)
        {
            obj = _obj;
            return true;
        }
    }

    public class Triable
    {
        public static async Task<ITriable<T>> ToTriableAsync<T>(Task<T> task)
        {
            return await Triable<T>.ToTriableAsync(task);
        }
    }
    
    public class Nothing<T> : ITriable<T>
    {
        public bool TryGet(out T obj)
        {
            obj = default(T);
            return false;
        }
    }    
}