std::time_get<CharT,InputIt>::get_time,std::time_get<CharT,InputIt>::do_get_time (3) - Linux Manuals

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

NAME

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

Synopsis

Defined in header <locale>
public:
iter_type get_time( iter_type beg, iter_type end, std::ios_base& str, (1)
std::ios_base::iostate& err, std::tm* t) const;
protected:
virtual iter_type get_time( iter_type beg, iter_type end, std::ios_base& str, (2)
std::ios_base::iostate& err, std::tm* t) const;

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 value 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

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

Return value

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

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.

Example

// Run this code

  #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::istreambuf_iterator<char> ret =
          std::use_facet<std::time_get<char>>(str.getloc()).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