LogicInTypeSystem.cs

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

namespace LogicInTypeSystem
{
    public class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
        public string Phone { get; set; }
    }

    public class PeoplesPhones
    {
        public string Name { get; set; }
        public string Phone { get; set; }
    }

    public class PeoplesAges
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }

    public static class PersonGetter
    {
        static PersonGetter()
        {
            // at some point around application initialize you need to instantiate your static PersonMap<T> instances...
            PersonMap<PeoplesPhones>.MappingFunc = (person) => new Person { Name = person.Name, Phone = person.Phone };
            PersonMap<PeoplesAges>.MappingFunc = (person) => new Person { Name = person.Name, Age = person.Age };
        }

        private static class PersonMap<T>
        {
            public static Func<T, Person> MappingFunc { get; set; }
        }

        public static Person GetPerson<T>(this T target)
        {
            return PersonMap<T>.MappingFunc(target);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            PeoplesPhones phone = new PeoplesPhones { Name = "Foo", Phone = "Bar" };
            PeoplesAges age = new PeoplesAges { Name = "ooF", Age = 42 };

            Person personA = phone.GetPerson();
            Person personB =   age.GetPerson();

            Console.WriteLine("Name: {0}, Age: {1}, Phone: {2}", personA.Name, personA.Age, personA.Phone);
            Console.WriteLine("Name: {0}, Age: {1}, Phone: {2}", personB.Name, personB.Age, personB.Phone);
            Console.ReadLine();
        }
    }
}