std::time_get::date_order, std::time_get::do_date_order

From cppreference.com
< cpp‎ | locale‎ | time get
 
 
 
 
Defined in header <locale>
public:
dateorder date_order() const;
(1)
protected:
virtual dateorder do_date_order() const;
(2)
1) Public member function, calls the protected virtual member function do_date_order of the most derived class.
2) Returns a value of type std::time_base::dateorder, which describes the default date format used by this locale (expected by get_date() and produced by std::strftime() with format specifier '%x').

The valid values (inherited from std::time_base) are:

no_order the format contains variable items (week day, Julian day, etc), or this function is not implemented
dmy day, month, year (European locales)
mdy month, day, year (American locales)
ymd year, month, day (Asian locales)
ydm year, day, month (rare)

Parameters

(none)

Return value

A value of type dateorder

Notes

This function is optional, it may return no_order in every case.

Example

#include <iostream>
#include <locale>
 
void show_date_order()
{
    std::time_base::dateorder d = std::use_facet<std::time_get<char>>(
                                           std::locale()
                                  ).date_order();
    switch (d)
    {
        case std::time_base::no_order: std::cout << "no_order\n"; break;
        case std::time_base::dmy: std::cout << "day, month, year\n"; break;
        case std::time_base::mdy: std::cout << "month, day, year\n"; break;
        case std::time_base::ymd: std::cout << "year, month, day\n"; break;
        case std::time_base::ydm: std::cout << "year, day, month\n"; break;
    }
}
 
int main()
{
    std::locale::global(std::locale("en_US.utf8"));
    std::cout << "In U.S. locale, the default date order is: ";
    show_date_order();
 
    std::locale::global(std::locale("ja_JP.utf8"));
    std::cout << "In Japanese locale, the default date order is: ";
    show_date_order();
 
    std::locale::global(std::locale("de_DE.utf8"));
    std::cout << "In German locale, the default date order is: ";
    show_date_order();
}

Output:

In U.S. locale, the default date order is: month, day, year
In Japanese locale, the default date order is: year, month, day
In German locale, the default date order is: day, month, year

See also

[virtual]
extracts month, day, and year from input stream
(virtual protected member function)
defines date format constants
(class)