In file included from /in/driver/main.cpp:8:0:
/in/kdtree.hpp: In instantiation of 'KDTree<std::tuple<_Elements ...>, ValueType>::Node* KDTree<std::tuple<_Elements ...>, ValueType>::copy_tree(KDTree<std::tuple<_Elements ...>, ValueType>::Node*, KDTree<std::tuple<_Elements ...>, ValueType>::Node*) [with ValueType = std::__cxx11::basic_string<char>; KeyTypes = {int, int, int}]':
/in/kdtree.hpp:434:24:   required from 'KDTree<std::tuple<_Elements ...>, ValueType>::KDTree(const KDTree<std::tuple<_Elements ...>, ValueType>&) [with ValueType = std::__cxx11::basic_string<char>; KeyTypes = {int, int, int}]'
/in/driver/main.cpp:145:69:   required from here
/in/kdtree.hpp:389:38: error: unused parameter 'parent' [-Werror=unused-parameter]
    Node *copy_tree(Node *node, Node *parent){
                                      ^~~~~~
cc1plus: all warnings being treated as errors