c++ - cannot convert »boost::gregorian::date_duration« to »int -

i using boost libs , work int :

but receiving error :

cannot convert »boost::gregorian::date_duration« »int 

what ? please help, want check if date passed current date.. right answer not work with. (range.length())

#include <iostream> #include <boost/date_time/gregorian/gregorian.hpp> #include <ctime> #include <fstream>  namespace bdt = boost::gregorian; using namespace std;  int main(void) {  time_t = time(0); tm *ltm = localtime(&now);  //aktuelles datum     int y = 1900 + ltm->tm_year;     int d = ltm->tm_mday;     int m = 1 + ltm->tm_mon;     bdt::date today(bdt::date(y, m, d));   //ziel                               y   m   d       bdt::date electionday(bdt::date(2012, 6, 6));     bdt::date_period range(today, electionday);       std::cout  << range.length() << std::endl;             int z = range.length() ;          return 0; } 

assuming want integer represent number of days in period, then:

range.length().days() 

or, if want compare dates, can without converting periods, durations, integers, or else:

if (today > electionday) {     std::cout << "election day in past\n"; }