/in/foo.cc:6:12: error: expected ']' before numeric constant
    6 |     int v[[3]()][[3]()];
      |            ^
      |            ]
/in/foo.cc: In constructor 'Matrix3::Matrix3()':
/in/foo.cc:8:17: error: 'memset' was not declared in this scope
    8 |     Matrix3() { memset(v, 0, sizeof(v)); }
      |                 ^~~~~~
/in/foo.cc:2:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    1 | #include <iostream>
  +++ |+#include <cstring>
    2 | using namespace std;
/in/foo.cc: In constructor 'Matrix3::Matrix3(const int*)':
/in/foo.cc:14:18: error: invalid types 'int[int]' for array subscript
   14 |                 v[i][j] = data[idx++];
      |                  ^
/in/foo.cc: In member function 'Matrix3 Matrix3::operator+(const Matrix3&) const':
/in/foo.cc:21:22: error: invalid types 'int[int]' for array subscript
   21 |                 res.v[i][j] = v[i][j] + other.v[i][j];
      |                      ^
/in/foo.cc:21:32: error: invalid types 'const int[int]' for array subscript
   21 |                 res.v[i][j] = v[i][j] + other.v[i][j];
      |                                ^
/in/foo.cc:21:48: error: invalid types 'const int[int]' for array subscript
   21 |                 res.v[i][j] = v[i][j] + other.v[i][j];
      |                                                ^
/in/foo.cc: In member function 'Matrix3 Matrix3::operator-(const Matrix3&) const':
/in/foo.cc:29:22: error: invalid types 'int[int]' for array subscript
   29 |                 res.v[i][j] = v[i][j] - other.v[i][j];
      |                      ^
/in/foo.cc:29:32: error: invalid types 'const int[int]' for array subscript
   29 |                 res.v[i][j] = v[i][j] - other.v[i][j];
      |                                ^
/in/foo.cc:29:48: error: invalid types 'const int[int]' for array subscript
   29 |                 res.v[i][j] = v[i][j] - other.v[i][j];
      |                                                ^
/in/foo.cc: In member function 'Matrix3 Matrix3::operator*(const Matrix3&) const':
/in/foo.cc:39:26: error: invalid types 'int[int]' for array subscript
   39 |                     res.v[i][j] += v[i][k] * other.v[k][j];
      |                          ^
/in/foo.cc:39:37: error: invalid types 'const int[int]' for array subscript
   39 |                     res.v[i][j] += v[i][k] * other.v[k][j];
      |                                     ^
/in/foo.cc:39:53: error: invalid types 'const int[int]' for array subscript
   39 |                     res.v[i][j] += v[i][k] * other.v[k][j];
      |                                                     ^
/in/foo.cc: In member function 'Matrix3 Matrix3::operator*(int) const':
/in/foo.cc:48:22: error: invalid types 'int[int]' for array subscript
   48 |                 res.v[i][j] = v[i][j] * scalar;
      |                      ^
/in/foo.cc:48:32: error: invalid types 'const int[int]' for array subscript
   48 |                 res.v[i][j] = v[i][j] * scalar;
      |                                ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:62:15: error: expected ']' before numeric constant
   62 |     int data[[9]()];
      |               ^
      |               ]
/in/foo.cc:63:44: error: invalid types 'int[int]' for array subscript
   63 |     for (int i = 0; i < 9; ++i) cin >> data[i];
      |                                            ^
/in/foo.cc:64:16: error: invalid conversion from 'int' to 'const int*' [-fpermissive]
   64 |     Matrix3 m1(data);
      |                ^~~~
      |                |
      |                int
/in/foo.cc:10:24: note:   initializing argument 1 of 'Matrix3::Matrix3(const int*)'
   10 |     Matrix3(const int* data) {
      |             ~~~~~~~~~~~^~~~
/in/foo.cc:65:44: error: invalid types 'int[int]' for array subscript
   65 |     for (int i = 0; i < 9; ++i) cin >> data[i];
      |                                            ^
/in/foo.cc:66:16: error: invalid conversion from 'int' to 'const int*' [-fpermissive]
   66 |     Matrix3 m2(data);
      |                ^~~~
      |                |
      |                int
/in/foo.cc:10:24: note:   initializing argument 1 of 'Matrix3::Matrix3(const int*)'
   10 |     Matrix3(const int* data) {
      |             ~~~~~~~~~~~^~~~
/in/foo.cc:67:44: error: invalid types 'int[int]' for array subscript
   67 |     for (int i = 0; i < 9; ++i) cin >> data[i];
      |                                            ^
/in/foo.cc:68:16: error: invalid conversion from 'int' to 'const int*' [-fpermissive]
   68 |     Matrix3 m3(data);
      |                ^~~~
      |                |
      |                int
/in/foo.cc:10:24: note:   initializing argument 1 of 'Matrix3::Matrix3(const int*)'
   10 |     Matrix3(const int* data) {
      |             ~~~~~~~~~~~^~~~
/in/foo.cc:75:27: error: invalid types 'int[int]' for array subscript
   75 |             cout << res1.v[i][j] << " ";
      |                           ^
/in/foo.cc:80:27: error: invalid types 'int[int]' for array subscript
   80 |             cout << res2.v[i][j] << " ";
      |                           ^