preprocessor memes

bla.cs

#define interface void

using System;

namespace redefine
{
	class Program
	{
		static void Main(string[] args)
		{
			Console.WriteLine("Hello World!");
			Foo("hejsan");
			Greet("Kalle Anka");
		}

		public static interface Foo(string msg) {
			Console.WriteLine(msg);
		}

		#include "my_mixin.cs"
	}
}

bla.sh

#compile with 
cc -x c -P -E Program.cs -o Program1.cs

my_mixin.cs

public static interface Greet(string name) {
	Console.WriteLine("Hi there, " + name + "!");
}