/in/call.cpp:23:5: error: use of undeclared identifier 'priority_queue'
    priority_queue<Call> calls;
    ^
/in/call.cpp:23:20: error: 'Call' does not refer to a value
    priority_queue<Call> calls;
                   ^
/in/call.cpp:9:8: note: declared here
struct Call {
       ^
/in/call.cpp:23:26: error: use of undeclared identifier 'calls'; did you mean 'calloc'?
    priority_queue<Call> calls;
                         ^~~~~
                         calloc
/usr/include/stdlib.h:541:14: note: 'calloc' declared here
extern void *calloc (size_t __nmemb, size_t __size)
             ^
/in/call.cpp:27:9: error: use of undeclared identifier 'calls'; did you mean 'call'?
        calls.push(call);
        ^~~~~
        call
/in/call.cpp:25:14: note: 'call' declared here
        Call call;
             ^
/in/call.cpp:27:15: error: no member named 'push' in 'Call'
        calls.push(call);
        ~~~~~ ^
/in/call.cpp:32:13: error: use of undeclared identifier 'calls'
    while (!calls.empty() || !platinum.isEmpty() || !gold.isEmpty() || !silver.isEmpty() || !regular.isEmpty()) {
            ^
/in/call.cpp:36:17: error: use of undeclared identifier 'calls'
        while (!calls.empty() && calls.top().timestamp == tick - 1) {
                ^
/in/call.cpp:36:34: error: use of undeclared identifier 'calls'
        while (!calls.empty() && calls.top().timestamp == tick - 1) {
                                 ^
/in/call.cpp:37:25: error: use of undeclared identifier 'calls'
            Call call = calls.top();
                        ^
/in/call.cpp:38:13: error: use of undeclared identifier 'calls'; did you mean 'call'?
            calls.pop();
            ^~~~~
            call
/in/call.cpp:37:18: note: 'call' declared here
            Call call = calls.top();
                 ^
10 errors generated.
/in/Compile/Makefile:39: recipe for target 'buildCall' failed
make: *** [buildCall] Error 1