Is there a standard date/time class in C++?

Question

Does C++ stl have a standard time class? Or do I have to convert to c-string before writing to a stream. Example, I want to output the current date/time to a string stream:<

Answer 1

C++ now has the chrono libraries for date and time. This is documented on http://en.cppreference.com/w/cpp/chrono and http://www.cplusplus.com/reference/chrono/

Answer 2

Not part of STL but well known library is boost.

I would go the way of using boost::date. Here are some examples: http://www.boost.org/doc/libs/1_55_0/doc/html/date_time/date_time_io.html#date_time.io_tutorial.

If you did not try out boost yet I encourage you to do so as it saves you from a lot of nasty issues, as it masks most OS dependent things like threading for example. Many things in boost are header only (template libraries). However datetime requires a lib or dll.

Answer 3

There are get_time and put_time in <iomanip> header (i guess these came with C++11) which effectively does string formatting or parsing jobs.

Answer 4

There is also a ctime(&time_t) method which outputs string (char*).

Answer 5

Nitpicking: The STL being the Standard Template Library deals with generic container and algorithms etc. and is unlikely to incorporate classes for date handling and calculation even in the future…

The C++ Standard Library itself includes the STL and a previous version of the C standard library. The latter offers some date and time related functions via #include <ctime> which has already been mentioned above.

If wrapping (or simply using) these functions is sufficient (and quicker) than pulling in boost, go with these. There is nothing wrong with them.

Answer 6

OK. Here is closest I have found about directly writing time to a stream:

time_t t(time(NULL));   // current time
tm tm(*localtime(&t));  

std::locale loc("");    // current user locale
ostringstream sout;
const std::time_put<TCHAR> &tput =
    std::use_facet<std::time_put<TCHAR> >(loc);
tput.put(sout.rdbuf(), sout, _T('\0'), &tm, _T('x'));
sout << ends;

CString sTest(sout.str().c_str());

A very helpful guide is the Apache C++ Standard Library Reference Guide http://stdcxx.apache.org/doc/stdlibref/time-put.html#sec13