friend-function

I was struggling with the issue described in this question (declaring a template function as a friend of a template class), and I believe the 2nd answer is what I want to do (forward declare the template function, then name a specialization as a friend). I have a question about whether a slightly different solution is actually correct or just happens to work in Visual C++ 2008. Test code is: #include <iostream> // forward declarations template <typename T> class test; template <typename T> std::ostream& operator<<(std::ostream &out, const test<T> &t); template <typename T> class test { friend

I want to declare std::make_unique function as a friend of my class. The reason is that I want to declare my constructor protected and provide an alternative method of creating the object using unique_ptr . Here is a sample code: #include <memory> template <typename T> class A { public: // Somehow I want to declare make_unique as a friend friend std::unique_ptr<A<T>> std::make_unique<A<T>>(); static std::unique_ptr<A> CreateA(T x) { //return std::unique_ptr<A>(new A(x)); // works return std::make_unique<A>(x); // doesn't work } protected: A(T x) { (void)x; } }; int main() { std::unique_ptr<A