1 files changed, 6 insertions, 1 deletions
diff --git a/common/list.h b/common/list.h
index 2ad41fd..513f79c 100644
--- a/common/list.h
+++ b/common/list.h
@@ -22,10 +22,15 @@ class List : public B {
 		}
 		
 		//! Check if specified item is present in list.
-		bool contains(T item) {
+		bool contains(const T& item) {
 			return std::find(B::begin(), B::end(), item) != B::end();
 		}
 		
+		//! Count number of instances of specified item in list.
+		std::size_t count(const T& item) {
+			return std::count(B::begin(), B::end(), item);
+		}
+		
 		//! Delete item by index.
 		void del(std::size_t index) {
 			erase(B::begin() + index);