К
friend std::ostream& operator<<(std::ostream& out, const binary_tree<T>* tree) {
if (tree != nullptr) {
operator<<(out, tree->m_left.get());
out << tree->m_data << std::ends;
operator<<(out, tree->m_right.get());
return out;
}
else return out;
}
binary_tree<int> a{ 2, 10, 4, 3, 7, 12, 1, 0 };
std::cout << &a << std::endl;