namespace RotoTraslazione { class rttr; } namespace Punto_sul_piano { namespace RT = RotoTraslazione; class point { double x,y; public: point(const double&, const double&); friend point operator *(const point&, const RT::rttr&); friend void operator/(const char*, const point&); }; } 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); friend PP::point PP::operator *(const point&, const rttr&); friend void operator/(const char*, const rttr&); }; }