// stowatch.cpp       #include"stowatch.h"#include<cassert>#include <iostream>void Stopwatch::start(){     ftime(&starttime);      state        = running;}void Stopwatch::stop(){     ftime(&stoptime);      state        = halted;}double Stopwatch::duration(){     if(state == undefined)      assert(!("Stopwatch not started!\n"));      if (state == running)          ftime(&stoptime);      return double(stoptime.time - starttime.time)           + double(stoptime.millitm           - starttime.millitm)/1000.0;}