using System;

using System.Collections.Generic;

using NUnitLite;

using NUnit.Framework;

​

#nullable enable

var values = new List<Person>

{

    new("A", 20),

    new("B", 15)

};

values.Sort(LambdaComparer<Person>.Build((x, y) => x.Age.CompareTo(y.Age)));

Console.WriteLine(string.Join(Environment.NewLine, values));

record Person(string Name, int Age);

public class LambdaComparer<T> : IComparer<T>

{

    private readonly Func<T, T, int> _comparer;

    public LambdaComparer(Func<T, T, int> comparer) => _comparer = comparer;

    public int Compare(T x, T y) => _comparer(x, y);

    public static LambdaComparer<T> Build(Func<T, T, int> comparer) => new(comparer);

}