How to get current local format date from system in C or C++ which can be run on all platforms

Question

I am using this GetDateFormat method from MFC C++ to get the current date format from the system.

#include <windows.h>
#include <stdio.h>
#include <iostream>
using namespace std;

int main()
{
    SYSTEMTIME st, lt;
    TCHAR szTime[256];

    GetSystemTime(&st);
    GetLocalTime(&lt);
    GetDateFormat(LOCALE_USER_DEFAULT, DATE_SHORTDATE, &st, NULL, szTime, 250); // prints current date format from system

    cout << szTime << endl;
    return 0;
}

Scenario: If I change the date manually in my system from YYYY-DD-MM to DD-M-YY, then it should be print the updated date format if I run the program again.

With the above code I am able to achieve it but I think GetDateFormat is only specific to windows API. Is there any API to achieve the same in Mac OS and Linux?

Update:

Approach 2: Prints date in expected format but not sure if I can use this in all platforms?

/* setlocale example */
#include <stdio.h>      /* printf */
#include <time.h>       /* time_t, struct tm, time, localtime, strftime */
#include <locale.h>     /* struct lconv, setlocale, localeconv */

int main ()
{
  time_t rawtime;
  struct tm * timeinfo;
  char buffer [80];

  struct lconv * lc;

  time ( &rawtime );
  timeinfo = localtime ( &rawtime );
  int twice=0;

    setlocale (LC_ALL,"");
    strftime (buffer,80,"%x",timeinfo);
    printf ("Date is: %s\n",buffer); //prints date in expected format

  return 0;
}

Answer 1

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

int main()
{
    std::time_t t = std::time(nullptr);
    std::tm tm = *std::localtime(&t);

    // If you want to set a specific local then use the appropriate local object.
    std::locale lJP("ja_JP");
    std::cout.imbue(lJP);
    std::cout << std::put_time(&tm, "%Ec") << "\n";

    // To pull the system local used by your system then use the empty string.
    std::locale lSY("");
    std::cout.imbue(lSY);
    std::cout << std::put_time(&tm, "%x") << "\n";
}

Running this:

> ./a.out
金  4/24 09:42:27 2020
Fri Apr 24 09:42:27 2020

You can find the standard valid conversions here: