/in/foo.cc:5:12: error: expected ']' before numeric constant
    5 |     int v[[3]()][[3]()];
      |            ^
      |            ]
/in/foo.cc: In constructor 'Matrix3::Matrix3(const int*)':
/in/foo.cc:11:18: error: invalid types 'int[int]' for array subscript
   11 |                 v[i][j] = arr[i*3 + j];
      |                  ^
/in/foo.cc: In member function 'Matrix3 Matrix3::operator+(const Matrix3&) const':
/in/foo.cc:18:22: error: invalid types 'int[int]' for array subscript
   18 |                 res.v[i][j] = v[i][j] + o.v[i][j];
      |                      ^
/in/foo.cc:18:32: error: invalid types 'const int[int]' for array subscript
   18 |                 res.v[i][j] = v[i][j] + o.v[i][j];
      |                                ^
/in/foo.cc:18:44: error: invalid types 'const int[int]' for array subscript
   18 |                 res.v[i][j] = v[i][j] + o.v[i][j];
      |                                            ^
/in/foo.cc: In member function 'Matrix3 Matrix3::operator-(const Matrix3&) const':
/in/foo.cc:26:22: error: invalid types 'int[int]' for array subscript
   26 |                 res.v[i][j] = v[i][j] - o.v[i][j];
      |                      ^
/in/foo.cc:26:32: error: invalid types 'const int[int]' for array subscript
   26 |                 res.v[i][j] = v[i][j] - o.v[i][j];
      |                                ^
/in/foo.cc:26:44: error: invalid types 'const int[int]' for array subscript
   26 |                 res.v[i][j] = v[i][j] - o.v[i][j];
      |                                            ^
/in/foo.cc: In member function 'Matrix3 Matrix3::operator*(const Matrix3&) const':
/in/foo.cc:35:26: error: invalid types 'int[int]' for array subscript
   35 |                     res.v[i][j] += v[i][k] * o.v[k][j];
      |                          ^
/in/foo.cc:35:37: error: invalid types 'const int[int]' for array subscript
   35 |                     res.v[i][j] += v[i][k] * o.v[k][j];
      |                                     ^
/in/foo.cc:35:49: error: invalid types 'const int[int]' for array subscript
   35 |                     res.v[i][j] += v[i][k] * o.v[k][j];
      |                                                 ^
/in/foo.cc: In member function 'Matrix3 Matrix3::operator*(int) const':
/in/foo.cc:43:22: error: invalid types 'int[int]' for array subscript
   43 |                 res.v[i][j] = v[i][j] * k;
      |                      ^
/in/foo.cc:43:32: error: invalid types 'const int[int]' for array subscript
   43 |                 res.v[i][j] = v[i][j] * k;
      |                                ^
/in/foo.cc: In member function 'void Matrix3::print() const':
/in/foo.cc:54:26: error: invalid types 'const int[int]' for array subscript
   54 |                 cout << v[i][j] << (i==2&&j==2 ? "" : " ");
      |                          ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:60:18: error: expected ']' before numeric constant
   60 |     int k, data[[9]()];
      |                  ^
      |                  ]
/in/foo.cc:63:16: error: two consecutive '[' shall only introduce an attribute before '[' token
   63 |     cin >> data[[0]()]; Matrix3 m1(data);
      |                ^
/in/foo.cc:63:36: error: invalid conversion from 'int' to 'const int*' [-fpermissive]
   63 |     cin >> data[[0]()]; Matrix3 m1(data);
      |                                    ^~~~
      |                                    |
      |                                    int
/in/foo.cc:8:24: note:   initializing argument 1 of 'Matrix3::Matrix3(const int*)'
    8 |     Matrix3(const int* arr) {
      |             ~~~~~~~~~~~^~~
/in/foo.cc:64:16: error: two consecutive '[' shall only introduce an attribute before '[' token
   64 |     cin >> data[[0]()]; Matrix3 m2(data);
      |                ^
/in/foo.cc:64:36: error: invalid conversion from 'int' to 'const int*' [-fpermissive]
   64 |     cin >> data[[0]()]; Matrix3 m2(data);
      |                                    ^~~~
      |                                    |
      |                                    int
/in/foo.cc:8:24: note:   initializing argument 1 of 'Matrix3::Matrix3(const int*)'
    8 |     Matrix3(const int* arr) {
      |             ~~~~~~~~~~~^~~
/in/foo.cc:65:16: error: two consecutive '[' shall only introduce an attribute before '[' token
   65 |     cin >> data[[0]()]; Matrix3 m3(data);
      |                ^
/in/foo.cc:65:36: error: invalid conversion from 'int' to 'const int*' [-fpermissive]
   65 |     cin >> data[[0]()]; Matrix3 m3(data);
      |                                    ^~~~
      |                                    |
      |                                    int
/in/foo.cc:8:24: note:   initializing argument 1 of 'Matrix3::Matrix3(const int*)'
    8 |     Matrix3(const int* arr) {
      |             ~~~~~~~~~~~^~~