std::time_get<CharT,InputIt>::get_year, std::time_get<CharT,InputIt>::do_get_year
| Defined in header <locale>
|
||
| public: iter_type get_year( iter_type s, iter_type end, std::ios_base& str, |
(1) | |
| protected: virtual iter_type do_get_year( iter_type s, iter_type end, std::ios_base& str, |
(2) | |
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.
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 year.
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.
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
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
|
See also
| (C++11) |
parses a date/time value of specified format (function template) |