View Compilation Error

0_0_4009977_26634.cpp: In function `matrix quick(int, matrix&)':
0_0_4009977_26634.cpp:40: error: no match for 'operator*' in 'quick((n / 2), ((matrix&)(+m))) * quick((n / 2), ((matrix&)(+m)))'
0_0_4009977_26634.cpp:24: note: candidates are: matrix operator*(matrix&, matrix&)
0_0_4009977_26634.cpp:41: error: no match for 'operator*' in 'quick((n / 2), ((matrix&)(+m))) * quick((n / 2), ((matrix&)(+m)))'
0_0_4009977_26634.cpp:24: note: candidates are: matrix operator*(matrix&, matrix&)