#include "c1_namespace.h" using namespace my_namespace; int A::count = 0; A::A() { data = 0; ++count; } A::A(int d) { data = d; ++count; } int A::get_count() { return count; } // !!!!!!!!!!!!!!!!! namespace my_namespace { ostream& operator<<(ostream& out, A& obj) { out << "A.data = " << obj.data; return out; } } int main() { A a(3); cout << a << endl; cout << "count = " << A::get_count() << endl; return 0; }