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#include <iostream>
using namespace std;
 
 
template<class T>
class A {
protected:
	T m_i;
	virtual void m_set(T i) 
	{
		m_i=i;
	};
public:	
	template<typename ... Args>
	void setParams( Args&&... params ) 
	{ 
		m_set(std::forward<Args>(params)...); 
	}
	virtual void show()
	{ 
		cout << m_i << endl;
	}
};
 
 
template<class T, typename ... args>
class B: public A<T> {
protected:
	using A<T>::m_i;
    T m_j;
    virtual void m_set(T i, T j) 
    {
    	m_i=i;
    	m_j=j;
    }
public:	
	virtual void show() override 
	{ 
		cout << m_i << ':' << m_j << endl;
	} 
};
 
 
int main() {
	auto a = new A<int>;
	a->setParams(22);
	a->show();
 
	A<int>* b = new B<int>;
	a->setParams(22,23);
	a->show();
 
	return 0;
}

prog.cpp: In instantiation of ‘void A<T>::setParams(Args&& ...) [with Args = {int, int}; T = int]’:
prog.cpp:34:20:   required from here
prog.cpp:12:44: error: no matching function for call to ‘A<int>::m_set(int, int)’
  void setParams( Args&&... params ) { m_set(std::forward<Args>(params)...); }
                                       ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.cpp:9:15: note: candidate: void A<T>::m_set(T) [with T = int]
  virtual void m_set(T i) {m_i=i;};
               ^~~~~
prog.cpp:9:15: note:   candidate expects 1 argument, 2 provided

Standard output is empty