String& operator = (const float vv) throw() { std::string::clear(); return operator<< (vv); }
String& operator = (const double vv) throw() { std::string::clear(); return operator<< (vv); }
String& operator = (const std::string& vv) throw() { std::string::operator= (vv); return *this; }
String& operator = (const float vv) throw() { std::string::clear(); return operator<< (vv); }
String& operator = (const double vv) throw() { std::string::clear(); return operator<< (vv); }
String& operator = (const std::string& vv) throw() { std::string::operator= (vv); return *this; }