View Compilation Error

0_0_15029219_23298.cpp: In function 'void calc_primes()':
0_0_15029219_23298.cpp:12:40: error: 'memset' was not declared in this scope
     memset(primes, true, sizeof(primes));
                                        ^
0_0_15029219_23298.cpp: In function 'int main()':
0_0_15029219_23298.cpp:64:41: error: 'memset' was not declared in this scope
         memset(used, false, sizeof(used));
                                         ^