constと参照渡し（？）の使い方
C++Rect()consttopleftfloat &topfloat& top
class Rect{
public:
Rect(const float& top,const float& left,const float& bottom,const float& right){a = top; b = left; c = bottom; d = right;}
void member(){std::cout << a << b << c << d << std::endl;};
float getArea();
~Rect(){}
private:
float a, b, c, d;
};