Наследование шаблонных классов

#include <algorithm>
#include <vector>
#include <iostream>
#include <deque>
using namespace std;
 
// CLASS TEMPLATE queue
template <class _Ty, class _Container>
class Queue {
public:
    using value_type = typename _Container::value_type;
    using const_reference = typename _Container::const_reference;
  
    _NODISCARD bool empty() const noexcept(noexcept(c.empty())) /* strengthened */ {
        return c.empty();
    }
    _Container c{};
};
 
// CLASS TEMPLATE Priority_queue
template <class _Ty, class _Container, class _Pr = less<typename _Container::value_type>>
class Priority_queue: public Queue<_Ty, _Container> {
public:
    using value_type = typename _Container::value_type;
    using const_reference = typename _Container::const_reference;
          
    _NODISCARD bool empty() const noexcept(noexcept(c.empty())) /* strengthened */ {
        return c.empty();
    }
 
       _NODISCARD const_reference top() const noexcept(noexcept(c.front())) /* strengthened */ {
        return c.front();
    }
 
    void push(value_type&& _Val) {
        c.push_back(_STD move(_Val));
        _STD push_heap(c.begin(), c.end(), comp);
    }
 
    void pop() {
        _STD pop_heap(c.begin(), c.end(), comp);
        c.pop_back();
    }
    _Container c{};
     _Pr comp{};
};