using DotWhat.Contracts;
using System;
using System.Runtime.CompilerServices;

namespace DotWhat.DuckTyping
{
    public sealed class CustomAwaiters : What
    {
        public override string Name => "CustomAwaiters";

        public override async void Run()
        {
            const int i = 123;

            Console.WriteLine(await (await await 7 + await i));
        }
    }

    public static class IntExtensions
    {
        public static IntAwaiter GetAwaiter(this int i) => new IntAwaiter(i);
    }

    public sealed class IntAwaiter : INotifyCompletion
    {
        private readonly int _value;
        public bool IsCompleted => true;

        public IntAwaiter(int i) => _value = i;

        public int GetResult() => _value;

        public void OnCompleted(Action continuation)
        {
        }
    }
}