arg_binding

  template<typename return_type, typename arg1_type, typename ...params>
  auto _L1( return_type (*fp) (arg1_type x, params...args), arg1_type x)
    { return [fp, x] (params...args) { return fp(x,args...); };  };

  double mult(double x, double y) { return x*y; }
  auto to_radians = _L1(mult,M_PI/180.0);
  auto cos_in_degrees = _L(cos) * to_radians;
  cout << cos_in_degrees(45.0) << endl;