- "typename" is a synonym of "class" in template declaration

- Template template parameters

// basics/stack7decl.hpp 

template <typename T, 
          template <typename ELEM> class CONT = std::deque
> 
class Stack
{
private: 
	CONT<T> elems;         // elements 

public: 
	void push(T const &);  // push element 
	void pop();            // pop element 
	T top() const;         // return top element 
	bool empty() const     // return whether the stack is empty 
	{
		return elems.empty(); 
	} 
};