/in/foo.cc: In function 'int main()':
/in/foo.cc:62:36: error: no matching function for call to 'std::vector<std::vector<std::vector<bool> > >::push_back(std::vector<std::vector<int> >&)'
   62 |                 solutions.push_back(x);
      |                 ~~~~~~~~~~~~~~~~~~~^~~
In file included from /usr/include/c++/12/vector:64,
                 from /in/foo.cc:2:
/usr/include/c++/12/bits/stl_vector.h:1276:7: note: candidate: 'void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = std::vector<std::vector<bool> >; _Alloc = std::allocator<std::vector<std::vector<bool> > >; value_type = std::vector<std::vector<bool> >]'
 1276 |       push_back(const value_type& __x)
      |       ^~~~~~~~~
/usr/include/c++/12/bits/stl_vector.h:1276:35: note:   no known conversion for argument 1 from 'std::vector<std::vector<int> >' to 'const std::vector<std::vector<std::vector<bool> > >::value_type&' {aka 'const std::vector<std::vector<bool> >&'}
 1276 |       push_back(const value_type& __x)
      |                 ~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/12/bits/stl_vector.h:1293:7: note: candidate: 'void std::vector<_Tp, _Alloc>::push_back(value_type&&) [with _Tp = std::vector<std::vector<bool> >; _Alloc = std::allocator<std::vector<std::vector<bool> > >; value_type = std::vector<std::vector<bool> >]'
 1293 |       push_back(value_type&& __x)
      |       ^~~~~~~~~
/usr/include/c++/12/bits/stl_vector.h:1293:30: note:   no known conversion for argument 1 from 'std::vector<std::vector<int> >' to 'std::vector<std::vector<std::vector<bool> > >::value_type&&' {aka 'std::vector<std::vector<bool> >&&'}
 1293 |       push_back(value_type&& __x)
      |                 ~~~~~~~~~~~~~^~~
/in/foo.cc:71:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<std::vector<bool> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |         for (int k = 0; k < solutions.size(); ++k) {
      |                         ~~^~~~~~~~~~~~~~~~~~