View Compilation Error

0_0_30765845_13592.cpp:32:12: error: 'ull64_t' does not name a type
     static ull64_t splitmix64(ull64_t x) {
            ^
0_0_30765845_13592.cpp:38:23: error: 'ull64_t' has not been declared
     size_t operator()(ull64_t x) const {
                       ^
0_0_30765845_13592.cpp: In member function 'size_t custom_hash::operator()(int) const':
0_0_30765845_13592.cpp:39:22: error: 'ull64_t' does not name a type
         static const ull64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
                      ^
0_0_30765845_13592.cpp:40:31: error: 'FIXED_RANDOM' was not declared in this scope
         return splitmix64(x + FIXED_RANDOM);
                               ^
0_0_30765845_13592.cpp:40:43: error: 'splitmix64' was not declared in this scope
         return splitmix64(x + FIXED_RANDOM);
                                           ^