std::time_get<CharT,InputIt>:: get_weekday, std::time_get<CharT,InputIt>:: do_get_weekday

If it finds abbreviated name, followed by the characters that are valid for the full name, it continues reading until it consumes all the characters for the full name or finds a character that is not expected, in which case parsing fails even if the first few characters were a valid abbreviation.

The parsed weekday is stored in the std::tm field t - > tm_wday .

If the end iterator is reached before a valid weekday name is read, the function sets std::ios_base::eofbit in err . If a parsing error is encountered, the function sets std::ios_base::failbit in err .

Parameters

Return value

Iterator pointing one past the last character in [ beg , end ) that was recognized as a part of a valid weekday name.

Notes

This function is usually case-insensitive.

If a parsing error is encountered, most implementations of this function leave * t unmodified.

Example

#include <initializer_list>
#include <iostream>
#include <iterator>
#include <locale>
#include <sstream>
#include <string_view>
 
void try_get_wday(std::string_view s)
{
    std::cout << "Parsing the weekday out of '" << s
              << "' in the locale " << std::locale().name() << '\n';
    std::istringstream str{s.data()};
    std::ios_base::iostate err{std::ios_base::goodbit};
 
    std::tm t;
    std::time_get<char> const& facet = std::use_facet<std::time_get<char>>(str.getloc());
    std::istreambuf_iterator<char> ret = facet.get_weekday({str}, {}, str, err, &t);
    str.setstate(err);
    std::istreambuf_iterator<char> last{};
 
    if (str)
    {
        std::cout << "Successfully parsed, weekday number is " << t.tm_wday;
 
        if (ret != last)
        {
            std::cout << " Remaining content: ";
            std::copy(ret, last, std::ostreambuf_iterator<char>(std::cout));
        }
        else
            std::cout << " the input was fully consumed";
    }
    else
    {
        std::cout << "Parse failed. Unparsed string: ";
        std::copy(ret, last, std::ostreambuf_iterator<char>(std::cout));
    }
 
    std::cout << '\n';
}
 
void demo(std::string_view locale_name, std::initializer_list<std::string_view>&& data)
{
    try
    {
        std::locale::global(std::locale(locale_name.data()));
    }
    catch (std::runtime_error const& ex)
    {
        std::cout << "Cannot setup locale: " << locale_name << "\n"
                     "Exception: " << ex.what() << '\n';
        return;
    }
 
    for (std::string_view const weekday : data)
        try_get_wday(weekday);
}
 
int main()
{
    demo("lt_LT.utf8", {"Št", "Šeštadienis"});
    demo("en_US.utf8", {"SATELLITE"});
    demo("ja_JP.utf8", {"土曜日"});
}

Parsing the weekday out of 'Št' in the locale lt_LT.utf8
Successfully parsed, weekday number is 6 the input was fully consumed
Parsing the weekday out of 'Šeštadienis' in the locale lt_LT.utf8
Successfully parsed, weekday number is 6 the input was fully consumed
Parsing the weekday out of 'SATELLITE' in the locale en_US.utf8
Successfully parsed, weekday number is 6 Remaining content: ELLITE
Parsing the weekday out of '土曜日' in the locale ja_JP.utf8
Successfully parsed, weekday number is 6 the input was fully consumed

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also