I have been wondering why a simple vector manipulation scheme as the one below is not valid. The compiler says that the multipilcation (*3.0) operation does not exist. I am not sure how to use the std::vector library for this purpose. Would that method work in which the function vVAdd() would return a vector type and allow the multiplication? Much appreciation if anyone can help. Code: #include <iostream> #include <fstream> using namespace std; //class for vectors class Vect { public: double x, y, z; // vector units }; void vVAdd(Vect &v, Vect v1, Vect v2); int main () { Vect t1, t2, t3, t4; t1.x = 4.0, t1.y = 5.5, t1.z = 7.1; t2.x = 3.6, t2.y = 4.8, t2.z = 3.6; vVAdd(t3, t1, t2); t4 = t3*3.0; cout << t4.x << '\t' << t4.y << '\t' << t4.z << endl; } void vVAdd(Vect &v, Vect v1, Vect v2) { v.x = v1.x + v2.x; v.y = v1.y + v2.y; v.z = v1.z + v2.z; return; }

Welcome to G4EF. You probably posted the query in the wrong section. I have moved it at the correct place. You are operating on the object (*3.0) but that is allowed only when you have an overloaded operator.