namespace Punto_sul_piano { class point { double x,y; public: point(); point(const double&, const double&); friend ostream& operator<<(ostream&, const point&); double getx() const { return x; } double gety() const { return y; } }; } namespace RotoTraslazione { namespace PP = Punto_sul_piano; class rttr { double deg, co, si, xtr, ytr; public: rttr(const double&, const double& =0.0, const double& =0.0); PP::point operator()(const PP::point&); rttr operator!(); // calcola matrice inversa friend ostream& operator<<(ostream&, const rttr&); }; }