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std::time_get<CharT,InputIt>::get_time, std::time_get<CharT,InputIt>::do_get_time

From cppreference.com
< cpp‎ | locale‎ | time get
 
 
 
 
Defined in header <locale>
public:

iter_type get_time( iter_type beg, iter_type end, std::ios_base& str,

                    std::ios_base::iostate& err, std::tm* t ) const;
(1)
protected:

virtual iter_type do_get_time( iter_type beg, iter_type end, std::ios_base& str,

                               std::ios_base::iostate& err, std::tm* t ) const;
(2)
1) Public member function, calls the protected virtual member function do_get_time of the most derived class.
2) Reads successive characters from the sequence [beg, end) and parses out the time value following the same rules as the format specifier "%X" (until C++11) "%H:%M:%S" (since C++11) as used by the functions std::get_time, time_get::get, and the POSIX function strptime().
The parsed time is stored in the corresponding fields of the std::tm structure pointed to by the argument t.
If the end iterator is reached before a valid time 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.

Contents

[edit] 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
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

[edit] Return value

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

[edit] Notes

For the alphabetic components of the default time format (if any), this function is usually case-insensitive.

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

[edit] Example

#include <iostream>
#include <locale>
#include <sstream>
#include <iterator>
 
void try_get_time(const std::string& s)
{
    std::cout << "Parsing the time out of '" << s
              << "' in the locale " << std::locale().name() << '\n';
    std::istringstream str(s);
    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_time({str}, {}, str, err, &t);
    str.setstate(err);
 
    if (str)
    {
        std::cout << "Hours: "   << t.tm_hour << ", "
                     "Minutes: " << t.tm_min  << ", "
                     "Seconds: " << t.tm_sec  << '\n';
    }
    else
    {
        std::cout << "Parse failed. Unparsed string: ";
        std::copy(ret, {}, std::ostreambuf_iterator<char>(std::cout));
        std::cout << '\n';
    }
}
int main()
{
    std::locale::global(std::locale("ru_RU.utf8"));
    try_get_time("21:40:11");
    try_get_time("21-40-11");
 
    std::locale::global(std::locale("ja_JP.utf8"));
    try_get_time("21時37分58秒");
}

Output:

Parsing the time out of '21:40:11' in the locale ru_RU.utf8
Hours: 21, Minutes: 40, Seconds: 11
Parsing the time out of '21-40-11' in the locale ru_RU.utf8
Parse failed. Unparsed string: -40-11
Parsing the time out of '21時37分58秒' in the locale ja_JP.utf8
Hours: 21, Minutes: 37, Seconds: 58

[edit] Defect reports

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

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 time has not been read

[edit] See also

(C++11)
parses a date/time value of specified format
(function template) [edit]