+class JourneyTimeAscending : std::binary_function<Journey,Journey, bool> {
+public:
+ bool operator() (Journey const &lhs, Journey const &rhs) const {
+ return lhs.start < rhs.start;
+ }
+};
+
+class JourneyTimeDescending : std::binary_function<Journey,Journey, bool> {
+public:
+ bool operator() (Journey const &lhs, Journey const &rhs) const {
+ return lhs.start > rhs.start;
+ }
+};