/in/call.cpp:55:37: error: use of undeclared identifier 'top'
        while (!events.isEmpty() && top(events).time <= cur_t){
                                    ^
/in/call.cpp:56:23: error: use of undeclared identifier 'top'
            Event e = top(events);
                      ^
/in/call.cpp:58:13: error: use of undeclared identifier 'pop'
            pop(events);
            ^
/in/call.cpp:71:21: error: use of undeclared identifier 'top'
                e = top(platinum);
                    ^
/in/call.cpp:72:17: error: use of undeclared identifier 'pop'
                pop(platinum);
                ^
/in/call.cpp:75:21: error: use of undeclared identifier 'top'
                e = top(gold);
                    ^
/in/call.cpp:76:17: error: use of undeclared identifier 'pop'
                pop(gold);
                ^
/in/call.cpp:79:21: error: use of undeclared identifier 'top'
                e = top(silver);
                    ^
/in/call.cpp:80:17: error: use of undeclared identifier 'pop'
                pop(silver);
                ^
/in/call.cpp:83:21: error: use of undeclared identifier 'top'
                e = top(regular);
                    ^
/in/call.cpp:84:17: error: use of undeclared identifier 'pop'
                pop(regular);
                ^
11 errors generated.
/in/Compile/Makefile:39: recipe for target 'buildCall' failed
make: *** [buildCall] Error 1