IndexOf now also uses comparer.
IndexOf now also uses comparer.

--- a/include/boilerplate.hpp
+++ b/include/boilerplate.hpp
@@ -340,7 +340,7 @@
 		
 		do
 		{
-			if (this->Item(idx) == item) {
+			if (comparer(Item(idx), item) == 0) {
 				break;
 			}
 		} while (++idx < Count());