协变与逆变.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        public delegate TR MyDelegate<in T, out TR>(T t);
        static void Main(string[] args)
        {
            MyDelegate<string, object> dd = new MyDelegate<object, string>(t =>
            {
                return t.ToString();
            });

            Console.WriteLine(Print(dd));
            
        }

        public static object Print(MyDelegate<string, object> myde)
        {
            return myde("123".Remove(0,1));
        }
    }
}