/tmp/ccFc7cIa.o: In function `main': stub.cpp:(.text.startup+0x29a): undefined reference to `label(int, int, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >)' stub.cpp:(.text.startup+0x4bc): undefined reference to `find_next_station(int, int, std::vector<int, std::allocator<int> >)' collect2: error: ld returned 1 exit status