gistfile1.cs

using System;
using System.Linq;
using System.Collections.Generic;


namespace managers
{
	class MainClass
	{
		class Employee 
		{
			public string Name {
				get;
				set;
			}
		}
		
		class Manager : Employee
		{
		}
		
		class EmployeeCollection : List<Employee> 
		{
			private bool IsAManager(Employee e)
			{
				return e is Manager;
			}
			
			public Manager[] GetAllManagers()
			{
				return FindAll(IsAManager).Cast<Manager>().ToArray();	
			}
		}

		
		
		public static void Main (string[] args)
		{
			var employees = new EmployeeCollection();
			
			employees.Add(new Employee { Name = "Employee 1" });
			employees.Add(new Manager { Name = "Manager 1" });
			employees.Add(new Manager { Name = "Manager 2" });
				
			foreach(var manager in employees.GetAllManagers())
			{
				Console.WriteLine(manager.Name);	
			}
			
			Console.ReadKey();
		}
	}
}