Question

I would like to transfer a boost::posix_time::ptime over the network as a boost::int64_t. According to A way to turn boost::posix_time::ptime into an __int64, I can easily define my own epoch and only transfer the time_duration from that reference epoch as a 64 bits integer. But how to convert back to a ptime?

#include <iostream>
#include <cassert>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/date_time/gregorian/greg_month.hpp>

using namespace std;

using boost::posix_time::ptime;
using boost::posix_time::time_duration;
using boost::gregorian::date;

int main(int argc, char ** argv){
    ptime t = boost::posix_time::microsec_clock::local_time();

    // convert to int64_t
    ptime myEpoch(date(1970,boost::gregorian::Jan,1));
    time_duration myTimeFromEpoch = t - myEpoch;
    boost::int64_t myTimeAsInt = myTimeFromEpoch.ticks();

    // convert back to ptime
    ptime test = myEpoch + time_duration(myTimeAsInt);

    assert(test == t);
    return 0;
}

This is not working since the time_duration constructor taking a tick count as argument is private. I am also interested in any other way to simply transfer that ptime over simple data types.

Answer 1

Working solution with millisecond resolution:

int main(int argc, char ** argv){
    ptime t = boost::posix_time::microsec_clock::local_time();

    // convert to int64_t
    ptime myEpoch(date(1970,boost::gregorian::Jan,1));
    time_duration myTimeFromEpoch = t - myEpoch;
    boost::int64_t myTimeAsInt = myTimeFromEpoch.total_milliseconds();

    // convert back to ptime
    ptime test = myEpoch + boost::posix_time::milliseconds(myTimeAsInt);

    cout << test << endl;
    cout << t << endl;

    time_duration diff = test - t;

    assert(diff.total_milliseconds()==0);
    return 0;
}

Thanks 12a6.