using System;

class Base {}
class Derived: Base {}

public class GuardClass
{
    const int N = 100000;

    private static Base[] objs = new Base[N];

    public static void Init(string[] argv)
    {
        for (int i=0; i < N; i++) {
            if (i % 2 == 0)
                objs[i] = new Base();
            else
                objs[i] = new Derived();
        }
    }


    [Benchmark]
    public static int TestGuardClass()
    {
        int count = 0;
        for(int j=0; j < 1000; j++) 
            for(int i=0; i < N; i++) 
                if (objs[i].GetType() == typeof(Derived))
                    count++;
        return count;
    }

    [Benchmark]
    public static int TestIsInstance()
    {
        int count = 0;
        for(int j=0; j < 1000; j++) 
            for(int i=0; i < N; i++)
                if (objs[i] is Derived)
                    count++;
        return count;
    }
}