std::time_get<CharT,InputIt>::get_year, std::time_get<CharT,InputIt>::do_get_year
<locale>
iter_type get_year( iter_type s, iter_type end, std::ios_base & str,
virtual iter_type do_get_year( iter_type s, iter_type end, std::ios_base & str,
do_get_year of the most derived class.[beg, end) and parses out the year using some implementation-defined format. Depending on the locale, two-digit years may be accepted, and it is implementation-defined which century they belong to.The parsed year is stored in the std::tm structure field t->tm_year.
If the end iterator is reached before a valid year 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.
[edit] Parameters
[edit] Return value
Iterator pointing one past the last character in [beg, end) that was recognized as a part of a valid year.
[edit] Notes
For two-digit input values, many implementations use the same parsing rules as the conversion specifier '%y' as used by std::get_time , std::time_get::get() , and the POSIX function strptime(): two-digit integer is expected, the values in the range [69, 99] results in values 1969 to 1999, range [00, 68] results in 2000 to 2068. Four-digit inputs are typically accepted as-is.
If a parsing error is encountered, most implementations of this function leave *t unmodified.
[edit] Example
#include <iostream> #include <iterator> #include <locale> #include <sstream> void try_get_year(const std::string & s) { std::cout << "Parsing the year 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_year({str}, {}, str, err, &t); str.setstate(err); std::istreambuf_iterator <char> last{}; if (str) { std::cout << "Successfully parsed, year is " << 1900 + t.tm_year; 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'; } int main() { std::locale::global (std::locale ("en_US.utf8")); try_get_year("13"); try_get_year("2013"); std::locale::global (std::locale ("ja_JP.utf8")); try_get_year("2013年"); }
Possible output:
Parsing the year out of '13' in the locale en_US.utf8 Successfully parsed, year is 2013 the input was fully consumed Parsing the year out of '2013' in the locale en_US.utf8 Successfully parsed, year is 2013 the input was fully consumed Parsing the year out of '2013年' in the locale ja_JP.utf8 Successfully parsed, year is 2013 Remaining content: 年
[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 year has not been read
|