ctime - Can't time input: C++ -

i trying make game test c++ skills, , in game created class called player method function definition attack(). prints random string based on player method variable, , asks player input string in little time possible:

//definitions player int player::attack() {      std::cout << "you attacking. \n";      std::cout << "you must enter string in little time possible:";       std::string r = randstr(wordc);      std::cout << r << "\n";       std::string attack;      double seconds_since_start;      time_t start = time(0);      while (true)      {           std::cin >> attack;           if (attack == r) {break;}           seconds_since_start = difftime(time(0), start);      }      std::cout << "you typed word in " << seconds_since_start << "seconds\n"; } 

it doesn't work, , have looked everywhere answer. returns random numbers don't make sense. when see people using difftime() function, convert tm structure time_t variable , put second argument. need use this? type of data difftime() function return? doing wrong? compiler? appreciate help.

just place time measurement in if block before break; , delay correctly computed. but, next try when attack != r, have restart counter (if needed).

double seconds_since_start; time_t start = time(0); while (true) {     std::cin >> attack;     if (attack == r) {         // stop counter , measure delay         seconds_since_start = difftime(time(0), start);         break;     }     // restart counter (if needed)     start = time(0); } std::cout << "you typed word in " << seconds_since_start << "seconds\n";