chrono

I would like to print or extract year/month/day values. I don't want to use time_t because of the year 2038 problem, but all examples I found on the Internet use it to convert time_point to tm . Is there a simple way to convert from time_point to tm (preferably without boost )? An implementation like timesub from libc would be my last resort: http://www.opensource.apple.com/source/Libc/Libc-262/stdtime/localtime.c Edit: After reading the suggested links and doing some more research, I came to the following conclusion. Using time_t where it is 64bit long is ok (for most purposes). Using Boost

I'm using the steady_clock for saving the time stamp of some messages. For debug purpose is usefull to have the calendar (or something similar). For other clocks ther's the static function to_time_t , but on GCC (MinGW 4.8.0) this function is not present. Now i print something like: Timestamp: 26735259098242 For timestamp i need a steady_clock so I cannot use system_clock or others. Edit The previous print is given from the time_since_epoch().count () Ben Voigt Assuming you need the steady behavior for internal calculations, and not for display, here's a function you can use to convert to time

In C++11 you still have to use std::localtime and std::gmtime as indirection to print a std::chrono::time_point . These functions are not safe to use in a multithreaded environment as introduced with C++11 because they return a pointer to an internal static struct. This is especially annoying since C++11 introduced the convenient function std::put_time which is nearly unusable for the same reason. Why is this so fundamental broken or do I overlook something? According to N2661 , the paper that added <chrono> : This paper does not offer calendrical services except for a minimal mapping to and

How can I find out what type the compiler deduced when using the auto keyword? Example 1: Simpler auto tickTime = 0.001; Was this deduced as a float or a double? Example 2: More complex (and my present headache): typedef std::ratio<1, 1> sec; std::chrono::duration<double, sec > timePerTick2{0.001}; auto nextTickTime = std::chrono::high_resolution_clock::now() + timePerTick2; What type is nextTickTime ? The problem I'm having is when I try to send nextTickTime to std::cout . I get the following error: ./main.cpp: In function ‘int main(int, char**)’: ./main.cpp:143:16: error: cannot bind ‘std:

First off, I'm using Visual Studio 2015's implementation of the Filesystem library from the upcoming C++17 standard, which is based on Boost::Filesystem. Basically, what I'm trying to do is save a file's timestamp (it's "last write time"), copy that file's contents into an archive along with said timestamp, then extract that file back out and use the saved timestamp to restore the correct "last write time". // Get the file's 'last write time' and convert it into a usable integer. __int64 timestamp = chrono::time_point_cast<chrono::seconds>(fs::last_write_time(src)).time_since_epoch().count();

I just noticed that c++20 is going to have chrono::year . It's constructor takes in an int in the range: [-32767, 32767] , however I am unclear what this argument represents. Would this be consistent with tm_year 's 1900 origin? Or perhaps time_t 's 1970 origin? Or perhaps it's in Anno Domini with a 0 origin? EDIT: This is key to the understanding of what is meant by the is_leap function chrono::year offers. Without an origin it's unclear what year is represented here. In 25.8.1 [time.cal.general]: The types in 25.8 describe the civil (Gregorian) calendar and its relationship to sys_days and