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| Member functions | ||||
time_get::get_datetime_get::do_get_date | ||||
Defined in header <locale> | ||
public: iter_type get_date( iter_type beg, iter_type end,std::ios_base& str, | (1) | |
protected: virtual iter_type do_get_date( iter_type beg, iter_type end,std::ios_base& str, | (2) | |
do_get_date of the most derived class.[beg, end) and parses out the calendar date value using the default format expected by this locale, which is determined as| date_order() | Format |
|---|---|
no_order | "%m/%d/%y" |
dmy | "%d/%m/%y" |
mdy | "%m/%d/%y" |
ymd | "%y/%m/%d" |
ydm | "%y/%d/%m" |
Contents |
| 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 orstd::collate to compare strings |
| err | - | stream error flags object that is modified by this function to indicate errors |
| t | - | pointer to thestd::tm object that will hold the result of this function call |
Iterator pointing one past the last character in[beg, end) that was recognized as a part of a valid date.
For the alphabetic components of the default date format (if any), this function is usually case-insensitive.
If a parsing error is encountered, most implementations of this function leave*t unmodified.
The implementation may support other date formats besides the ones required by the standard.
#include <ctime>#include <iostream>#include <iterator>#include <locale>#include <sstream> void try_get_date(conststd::string& s){std::cout<<"Parsing the date 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;conststd::time_get<char>& facet=std::use_facet<std::time_get<char>>(str.getloc());std::istreambuf_iterator<char> ret= facet.get_date({str},{}, str, err,&t); str.setstate(err); if(str){std::cout<<"Day: "<< t.tm_mday<<' '<<"Month: "<< t.tm_mon+1<<' '<<"Year: "<< t.tm_year+1900<<'\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("en_US.utf8")); try_get_date("02/01/2013"); try_get_date("02-01-2013"); std::locale::global(std::locale("ja_JP.utf8")); try_get_date("2013年02月01日");}
Output:
Parsing the date out of '02/01/2013' in the locale en_US.utf8Day: 1 Month: 2 Year: 2013Parsing the date out of '02-01-2013' in the locale en_US.utf8Parse failed. Unparsed string: -01-2013Parsing the date out of '2013年02月01日' in the locale ja_JP.utf8Day: 1 Month: 2 Year: 2013
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 | setseofbit if a valid date has not been read |
| LWG 461 | C++98 | do_get_date needed to parse localized date representation | parses with the format determined bydate_order() |
(C++11) | parses a date/time value of specified format (function template)[edit] |
