using System;

using System.Text.Json;                 

public class Program

{

​

    public class Pet

    {

        public string Name {get;set;}

    }

    public class Dog : Pet

    {

        public int TagNumber {get;set;}

    }

​

    public static void Main()

    {

        Dog d = new Dog 

        {

            Name = "Fido",

            TagNumber = 1

        };

        Save(d); //Doesn't work

        TemplatedSave<Pet>(d); //Doesn't work

        TemplatedSave<Dog>(d); //Works, but complicates calling code

        TemplatedSave(d);//Works, but is another way of writing JsonSerializer.Serialize<object>(d)

        SaveAsObject(d); //Works great

        TypedSave(d); // Works great

    }

    public static void Save(Pet petToSave)

    {

        string x = JsonSerializer.Serialize(petToSave);

        Console.WriteLine(x);

    }

    public static void TemplatedSave<T>(T petToSave)

    {

        string x = JsonSerializer.Serialize<T>(petToSave);

        Console.WriteLine(x);

    }

    public static void SaveAsObject(Pet petToSave)

    {

        string x = JsonSerializer.Serialize((object)petToSave);

        Console.WriteLine(x);

    }

    public static void TypedSave(Pet petToSave)

    {

        string x = JsonSerializer.Serialize(petToSave, petToSave.GetType());

        Console.WriteLine(x);

    }

​

}