"Struct With Custom Parameterless Constructor as Field"

public readonly struct User {
	public readonly string Name;
	public readonly int Age;

	public User() {
		Name = "<no name>";
		Age = -1;
	}
}

public sealed class UserWrapper {
	public User WrappedUser { get; }
}

// ...

var uw = new UserWrapper();
Console.WriteLine(uw.WrappedUser.Name + " " + uw.WrappedUser.Age); // What do you think this will print?


Code snippet taken from "Complete C# Quick Reference - C# 10".