View Compilation Error

0_0_36446491_475.cpp: In function 'Matrix getInv(Matrix)':
0_0_36446491_475.cpp:137:14: error: expected unqualified-id before '[' token
         auto [i, j] = swap_vec.back();
              ^
0_0_36446491_475.cpp:138:20: error: 'i' was not declared in this scope
         swap(inv.a[i], inv.a[j]);
                    ^
0_0_36446491_475.cpp:138:30: error: 'j' was not declared in this scope
         swap(inv.a[i], inv.a[j]);
                              ^