View Compilation Error

0_0_24395320_703.cpp: In function 'int main()':
0_0_24395320_703.cpp:5:42: error: 'memset' was not declared in this scope
 #define cls(x) memset(x, false, sizeof(x))
                                          ^
0_0_24395320_703.cpp:34:9: note: in expansion of macro 'cls'
         cls(map);
         ^