How do I construct an ISO 8601 datetime in C++?

Question

I\'m working with the Azure REST API and they are using this to create the request body for table storage:

DateTime.UtcNow.ToString(\"o\")

Answer 1

I should point out I am a C++ newb.

I needed string with a UTC ISO 8601 formatted date and time that included milliseconds. I did not have access to boost.

This is more of a hack than a solution, but it worked well enough for me.

std::string getTime()
{
    timeval curTime;

    gettimeofday(&curTime, NULL);

    int milli = curTime.tv_usec / 1000;
    char buf[sizeof "2011-10-08T07:07:09.000Z"];
    strftime(buf, sizeof buf, "%FT%T", gmtime(&curTime.tv_sec));
    sprintf(buf, "%s.%dZ", buf, milli);

    return buf;
}

The output looks like: 2016-04-13T06:53:15.485Z