Traits for C#

trait.cs

interface BinaryOp {
	int Apply (int a, int b);
}

struct Multiply {
	public int Apply (int a, int b) {
		return a * b;
	}
}

static void Main () {
	var m = new Multiply ();
	var t = Trait<BinaryOp>.Make (ref m); //takes a ref, no boxing.
	var res = t.As ().Apply (10, 20); // == 200
}