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

Header: <locale>

Public member function, calls the protected virtual member function do_get_weekday of the most derived class.

# Declarations

public:
iter_type get_weekday( iter_type beg, iter_type end, std::ios_base& str,
std::ios_base::iostate& err, std::tm* t ) const;

protected:
virtual iter_type do_get_weekday( iter_type beg, iter_type end, std::ios_base& str,
std::ios_base::iostate& err, std::tm* t ) const;

# Parameters

beg: iterator designating the start of the sequence to parse
end: one past the end iterator for the sequence to parse
str: a stream object that this function uses to obtain locale facets when needed, e.g. std::ctype to skip whitespace or std::collate to compare strings
err: stream error flags object that is modified by this function to indicate errors
t: pointer to the std::tm object that will hold the result of this function call

# 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"});
}

# Defect reports

DR	Applied to	Behavior as published	Correct behavior
LWG 248	C++98	eofbit was not set upon reaching the end iterator	sets eofbit if a valid weekday name has not been read

# See also

get_time