Implemented `Delete` in terms of `Remove`

* analogously to how `Contains` is implemented as a wrapper around `Any`
* added appropriate test case and lessened restrictions on `Contains`'s comparator

2 files changed, 27 insertions, 3 deletions

diff --git a/src/list/operation/contains.h b/src/list/operation/contains.h
index 9e752ed..d3f95fa 100644
--- a/src/list/operation/contains.h
+++ b/src/list/operation/contains.h
@@ -1,6 +1,7 @@
 #ifndef TYPEASVALUE_SRC_LIST_OPERATION_CONTAINS_H_
 #define TYPEASVALUE_SRC_LIST_OPERATION_CONTAINS_H_
 
+#include "type.h"
 #include "higher/query.h"
 
 namespace tav {
@@ -12,9 +13,7 @@ template <
 class Contains {
 	private:
 		template <typename Current>
-		struct comparator {
-			typedef std::is_same<Current, Element> type;
-		};
+		using comparator = EqualValue<Current, Element>;
 
 	public:
 		typedef typename Any<comparator, List>::type type;
diff --git a/src/list/operation/delete.h b/src/list/operation/delete.h
new file mode 100644
index 0000000..ad0a4cf
--- /dev/null
+++ b/src/list/operation/delete.h
@@ -0,0 +1,25 @@
+#ifndef TYPEASVALUE_SRC_LIST_OPERATION_DELETE_H_
+#define TYPEASVALUE_SRC_LIST_OPERATION_DELETE_H_
+
+#include "type.h"
+#include "higher/filter.h"
+
+namespace tav {
+
+template <
+	typename Element,
+	typename List
+>
+class Delete {
+	private:
+		template <typename Current>
+		using comparator = EqualValue<Current, Element>;
+
+	public:
+		typedef typename Remove<comparator, List>::type type;
+
+};
+
+}
+
+#endif  // TYPEASVALUE_SRC_LIST_OPERATION_DELETE_H_