Remove std::binary_function

src/artis-star/common/event/InternalEvent.hpp

@@ -29,8 +29,6 @@
 
 #include "artis-star/common/Model.hpp"
 
-#include <functional>
-
 namespace artis::common {
 
 template<typename Time>
@@ -74,8 +72,7 @@ private:
 };
 
 template<typename Event>
-struct EventCompare
-  : std::binary_function<Event, Event, bool> {
+struct EventCompare {
   bool operator()(const Event &left, const Event &right) const { return left >= right; }
 };