How to overload the ostream operator << to make it work with log4cxx in C++?

Question

Say I have a class A and an operator<< declared like so:

// A.h
class A
{
    // A stuff
};
std::ostream& operator<<(std::ostream& os, co         


        

Answer 1

You could try declaring your operator << in namespace std (that's legal, since you're passing an instance of your user-defined type):

namespace std {
   ostream& operator<<(ostream& os, const A& a);
}