类模板的多重继承，为什么在调用基类构造函数时会出错？

Question

#include<iostream>
using namespace std;
template<class T>
class Point
{
public:
	T x, y;
	Point(T a, T b) :x(a),y(b){}
};
template<class T>
class Square : public Point<T>
{
public:
	T a;
	Square(T a,T b,T aa):Point(a,b),a(aa) {}
};
template<class T>
class Circle :public Point<T>
{
public:
	T r;
	Circle(T a, T b, T aa) :Point(a, b), r(aa) {}
};
template<class T>
class Solve :public Square<T>, public Circle<T>
{
public:
	void solve()
	{
		const T dis = Square::a / 2 + Circle::r;
		const T dx = abs(Square::x - Circle::x);
		const T dy = abs(Square::y - Circle::y);
		if (dis < dx && dis < dy)
			cout << "hh";
		else
			cout << "qq";
	}
public:
	Solve(T x1,T y1,T x2,T y2,T a,T r) : Square(x1,y1,a), Circle(x2,y2,r) {}
};
int main()
{
	double x1, y1, x2, y2, a, r;
	cin >> x1 >> y1 >> x2 >> y2 >> a >> r;
	Solve<double> s(x1, y1, x2, y2, a, r);
	
}

Circle Square都是Point的派生类，Solve继承于Circle Square，在调用他们的构造函数出错，报错为非法成员初始化，请问是什么原因？

Answer 1

当类被设置为类模板的以后，类名就变成了Square<T>，将上述代码中的Square替换即可