Duct-typed extension methods Example 10

Example10.cs

// Example 10: add a tuple

// This is just a dummy class that we can use in the example
public class City
{
  public City(string name, int population, string country)
  {
    Name = name;
    Population = population;
    Country = country;
  }

  public string Name { get; }
  public int Population { get; }
  public string Country { get; }
}

// This is the very specific extension method for adding a city to a list from Example 8
public static void Add(this List<City> list, string name, int population, string country)
=> list.Add(new City(name, population, country));

// We can gather up all the parameters in a tuple
public static void Add(this List<City> list, (string name, int population, string country) city)
=> list.Add(city.name, city.population, city.country);

// Now we have parenthesis, not curly braces
var cities = new List<City> 
{
  ("Chongqing", population: 30_751_600, "China"),
  ("Shanghai", population: 24_256_800, "China"),
  ("Delhi", population: 11_034_555, "India"),
  ("Beijing", population: 21_516_000, "China"),
  ("Dhaka", population: 14_399_000, "Bangladesh")
};

// Output each item, to see if things work correctly
foreach(var city in cities)
{
  Console.WriteLine($"{city.Name}: {city.Population} ({city.Country})");
}