View Compilation Error

0_0_34369567_515.cpp: In function 'mat power(mat, ll)':
0_0_34369567_515.cpp:21:27: error: cannot convert 'mat' to 'void*' for argument '1' to 'void* memset(void*, int, size_t)'
  memset(c, 0, sizeof c.mat);
                           ^