In file included from /in/Compile/BinarySearchTree_compile_check.cpp:4:0:
/in/BinarySearchTree.h: In static member function 'static BinarySearchTree<T, Compare>::Node* BinarySearchTree<T, Compare>::insert_impl(BinarySearchTree<T, Compare>::Node*, const T&, Compare) [with T = int; Compare = std::less<int>]':
/in/BinarySearchTree.h:474:3: error: control reaches end of non-void function [-Werror=return-type]
   }
   ^
/in/BinarySearchTree.h: In static member function 'static BinarySearchTree<T, Compare>::Node* BinarySearchTree<T, Compare>::insert_impl(BinarySearchTree<T, Compare>::Node*, const T&, Compare) [with T = Duck; Compare = DuckWealthLess]':
/in/BinarySearchTree.h:474:3: error: control reaches end of non-void function [-Werror=return-type]
   }
   ^
cc1plus: all warnings being treated as errors
/in/Compile/Makefile:30: recipe for target 'BinarySearchTree_compile_check.exe' failed
make: *** [BinarySearchTree_compile_check.exe] Error 1