/in/foo.cc: In function 'void get_to(std::__cxx11::string, std::array<int, 11ul>&)':
/in/foo.cc:11:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define for_range(i, l, r) for(int i = (l); i < (r); i++)
                                               ^
/in/foo.cc:64:3: note: in expansion of macro 'for_range'
   for_range(i, 0, a.size()){
   ^~~~~~~~~