NTSTATUS hStatus;
SYSTEM_PERFORMANCE_INFORMATION             stSysPerfInfo;

hStatus = NtQuerySystemInformation(SystemPerformanceInformation, &stSysPerfInfo, sizeof(stSysPerfInfo), NULL);
if (hStatus != NO_ERROR)
{
  // Do work....
}

void f()
{
   std::clock_t init = std::clock();
   // perform some operations
   std::clock_t end = std::clock();
   std::cout << end-init << " cpu ticks spent, or about "
             << (end-init)/CLOCKS_PER_SEC << " seconds." << std::endl;
}