I'm new to C and am exploring the use of timezones in chrono, specifically zoned_time. I have only one issue with it: I want to use an instance of zoned_time as a member in a class, but no matter how I alter the syntax, the compiler doesn't like it.

#include <chrono>

#pragma once
class Event
{
private:
    std::chrono::zoned_time tz;
public:
    Event();
};

I've created a header file containing the code above, but it says the argument list for the class template is missing. I assume that means it wants me to initialize it, but I don't want to because it's a header file. As I said, I messed around quite a bit with the syntax of tz, combined with a good bit of research. Unfortunately, since I'm new to the language I really don't know what to look for online.

So my goal here is to be able to create a typed container within Event which will store the zoned_time information. I'm not picky on how I achieve that goal (I suspect some black-magic pointer trickery will be the solution). Thank you for the input.

CodePudding user response：

Your error message mentions the word "template", indicating it's not about constructor arguments (initializer), but about generic type arguments (template parameters).

According to https://en.cppreference.com/w/cpp/chrono/zoned_time this class is declared as:

template <
    class Duration,
    class TimeZonePtr = const std::chrono::time_zone*
> class zoned_time;

So it seems like you need a duration type to use (there is a default for the time zone pointer type). So your line should probably say something like

    std::chrono::zoned_time<std::chrono::seconds> tz;