One approach to creating an ISO 8601 datetime format in C++ is to use the std::put_time function that is part of the C++ Standard Library. Here is an example code snippet that demonstrates this approach:
#include <iostream>
#include <iomanip>
#include <chrono>
int main() {
std::chrono::system_clock::time_point now = std::chrono::system_clock::now();
std::time_t time = std::chrono::system_clock::to_time_t(now);
struct tm local_tm;
localtime_s(&local_tm, &time);
char buffer[50];
std::strftime(buffer, sizeof(buffer), "%Y-%m-%dT%H:%M:%S%z", &local_tm);
std::cout << buffer << std::endl;
return 0;
}
In this example, we first create a system_clock::time_point
object representing the current time, and then convert it to a time_t
object. We use the localtime_s
function to get the local time as a tm
struct, which we then pass to the strftime
function to format it according to the ISO 8601 standard. Finally, we print the resulting string to the console.
Note that the %z
format specifier in the strftime
call gives the timezone offset in the format of +HHMM or -HHMM, depending on whether it is east or west of GMT. This is not strictly required for ISO 8601, but is a common convention.
There are other ways to achieve the same result, such as using libraries like Boost or strftime.net, or manually formatting the string using string manipulation operations.
Asked: 2021-07-30 11:00:00 +0000
Seen: 8 times
Last updated: May 08 '22