I have the following code: #ifndef PRIORITY_QUEUE__ #define PRIORITY_QUEUE__ #include <queue> template"<"class T, class S">" class PriorityQueue{ public: PriorityQueue(); void enqueue(T element); T dequeue(); void makeheap(); bool isEmpty(); private: priority_queue"<"T, vector"<"T">", S">" PQ; }; #endif I get the following errors: d:\datastructure\ex2\ex2\ex2\priorityqueue.h(16) : error C2143: syntax error : missing ';' before '<' d:\datastructure\ex2\ex2\ex2\priorityqueue.h(19) : see reference to class template instantiation 'PriorityQueue' being compiled d:\datastructure\ex2\ex2\ex2\priorityqueue.h(16) : error C2501: 'priority_queue' : missing storage-class or type specifiers d:\datastructure\ex2\ex2\ex2\priorityqueue.h(19) : see reference to class template instantiation 'PriorityQueue' being compiled d:\datastructure\ex2\ex2\ex2\priorityqueue.h(16) : error C2059: syntax error : '<' d:\datastructure\ex2\ex2\ex2\priorityqueue.h(19) : see reference to class template instantiation 'PriorityQueue' being compiled d:\datastructure\ex2\ex2\ex2\priorityqueue.h(18) : error C2238: unexpected token(s) preceding ';' d:\datastructure\ex2\ex2\ex2\priorityqueue.h(19) : see reference to class template instantiation 'PriorityQueue' being compiled PQ.CPP d:\datastructure\ex2\ex2\ex2\priorityqueue.h(16) : error C2143: syntax error : missing ';' before '<' d:\datastructure\ex2\ex2\ex2\priorityqueue.h(19) : see reference to class template instantiation 'PriorityQueue' being compiled d:\datastructure\ex2\ex2\ex2\priorityqueue.h(16) : error C2501: 'priority_queue' : missing storage-class or type specifiers d:\datastructure\ex2\ex2\ex2\priorityqueue.h(19) : see reference to class template instantiation 'PriorityQueue' being compiled d:\datastructure\ex2\ex2\ex2\priorityqueue.h(16) : error C2059: syntax error : '<' d:\datastructure\ex2\ex2\ex2\priorityqueue.h(19) : see reference to class template instantiation 'PriorityQueue' being compiled d:\datastructure\ex2\ex2\ex2\priorityqueue.h(18) : error C2238: unexpected token(s) preceding ';' d:\datastructure\ex2\ex2\ex2\priorityqueue.h(19) : see reference to class template instantiation 'PriorityQueue' being compiled Error executing cl.exe. ex2.exe - 8 error(s), 0 warning(s) What is wrong? And does the vector class is inside queue header? [edited by - The C modest god on May 25, 2004 3:55:04 AM]

How do I use "<" in code?

The only file that uses this file is:

#ifndef LIBRARY2_H__
#define LIBRARY2_H__

#include &ltiostream>
#include &ltstring>
#include "PriorityQueue.h"

using namespace std;

/********************************************************************************/
/* The basic Event class
Pure virtual class
*/
class Event {
public:
Event (unsigned int _time = 0) : time(_time) { }

virtual ~Event() { }

// Return true if this event occurs earlier than the argument
virtual bool less(const Event& other) = 0;

// Return pointer to new event; 0 if no such event exists
virtual Event* process() = 0;

// Return a string representation of the event
virtual string toString() = 0;

// Return time of occurence
unsigned getTime() const { return time; }
protected:
const unsigned int time;
};

/* Comparison class for events
(Objects of this class are functors)
*/
struct EventComparison{
bool operator () (Event* first, Event* second){
return(second->less(*first));
}
};


/********************************************************************************/

/* The basic Simulation paradigm
Events are held in a priority queue, sorted according to their time
*/
class Simulation{
public:
// Construct a new simulation ending at end_time
Simulation(unsigned _end_time)
: eventQueue(), time(0), end_time(_end_time) { }

// Schedule an event
void schedule(Event* newEvent) { eventQueue.enqueue(newEvent); }

// Run the simulation
void run(){
eventQueue.makeheap();
while( !eventQueue.isEmpty() && (time < end_time)){
Event* current = eventQueue.dequeue();
time = current-&gtgetTime();
Event* next = current->process();
cout << "[Time: " << time << "] " << current->toString() << endl;
if(next) schedule(next);
delete(current);
}
while( !eventQueue.isEmpty() ) delete(eventQueue.dequeue());
}
private:
PriorityQueue&ltEvent*, EventComparison> eventQueue;
unsigned int time;
const unsigned int end_time;
};

#endif


I have added the following code and it still does the missing ; before < error:

struct EventComparison2{
bool operator () (int first, int second){
return first;
}
};

priority_queue
&ltint,
vector&ltint>, EventComparison2> PQ;


Thanks for the replies, I fixed the problem.
Just needed to add #include and using namespace std