View Compilation Error

0_0_29985700_20208.cpp: In constructor 'Matrix::Matrix(int, int)':
0_0_29985700_20208.cpp:13:25: error: 'memset' was not declared in this scope
   memset(v, 0, sizeof(v));
                         ^
0_0_29985700_20208.cpp: In member function 'void Matrix::clear()':
0_0_29985700_20208.cpp:16:25: error: 'memset' was not declared in this scope
   memset(v, 0, sizeof(v));
                         ^