Intro To Pattern Matching – Covers C# 9(c-sharpcorner.com)

     namespace Bored
     {
        using System;
        using System.Collections.Generic;
        using System.Linq;
        using static System.Console;
        internal static class Program
        {
           private static void Main()
           {
              var addFive = Add.Partial(5);
              addFive(6).Print(); // Prints 11
              Enumerable.Range(0, 5).Select(addFive).ForEach(WriteLine); // Prints 5 to 9
           }
           private static Func<int, int, int> Add = (int x, int y) => x + y;
        }

        internal static class Extensions
        {
             public static Func<T2, TR> Partial<T1, T2, TR>(this Func<T1, T2, TR> func, T1 t1) => t2 => func(t1, t2);
             public static void Print<T>(this T t) => WriteLine(t);
             public static void ForEach<T>(this IEnumerable<T> xs, Action<T> f) => xs.ToList().ForEach(f);
         }
     }