A class template definition looks like a regular class definition, except it is prefixed by the keyword template. For example, here is the definition of a class template for a Stack.

template <class T>
class Stack
{
public:
	Stack(int = 10); 
	~Stack() { delete [] stackPtr; }
	int push(const T&); 
	int pop(T&);  
	int isEmpty()const { return top == -1; } 
	int isFull() const { return top == size - 1; } 
private:
	int size;  // number of elements on Stack.
	int top;  
	T* stackPtr;  
};

T is a type parameter and it can be any type. For example, Stack<Token>, where Token is a user defined class. T does not have to be a class type as implied by the keyword class. For example, Stack<int> and Stack<Message*> are valid instantiations, even though int and Message* are not "classes".