std::put_time implementation status in GCC?

问题

I was trying to compile this example program using GCC (tested versions 4.5.1, 4.6.3, 4.8.4):

#include <iostream>
#include <iomanip>
#include <ctime>
#include <chrono>

using std::chrono::system_clock;

int main()
{
    system_clock::time_point now = system_clock::now();
    std::time_t now_c = system_clock::to_time_t(
                            now - std::chrono::hours(24));
    std::cout << \"One day ago, the time was \"
              << std::put_time(std::localtime(&now_c), \"%F %T\") << \'\\n\';
}

But it tells me:

prog.cpp: In function \'int main()\':
prog.cpp:14:18: error: \'put_time\' is not a member of \'std\'

I thought, probably it\'s not implemented yet. So I tried to check the implementation status for this function. I only found this page:

http://gcc.gnu.org/projects/cxx0x.html

but there I could not find any note on put_time or chrono or alike. Can anyone point me to a resource that provides information on the implementation status for this library?

回答1:

See TODO extended iomanip manipulators std::get_time and std::put_time for gcc 4.8.0.

See also Cross Platform way to get the time of day? claiming that is not implemented in 4.7.0.

UPDATE: As the gcc developer Jonathan Wakely confirmed below: The std::get_time and std::put_time manipulators are still missing in gcc 4.9.

UPDATE: Jonathan Wakely closed this ticket on 22 Dec, 2014:

Fixed for GCC 5

Thanks simonwo for letting me know about it.

回答2:

You might have noticed the link you gave doesn't list any parts of the library! But below the table it says:

The status of the library implementation can be tracked in this table

That table notes that std::get_time and std::put_time manipulators are not implemented yet.

Edit: put_time is now on the GCC development trunk.

来源：https://stackoverflow.com/questions/14136833/stdput-time-implementation-status-in-gcc

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