std::time_get::get_date, std::time_get::do_get_date
From cppreference.com
Defined in header <locale>
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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) | |
1) Public member function, calls the protected virtual member function
do_get_date()
of the most derived class.2) Reads successive characters from the sequence
[beg, end)
and parses out the calendar date value using the default format expected by this locale, which is the same format as"%x" | (until C++11) |
"%d/%m/%y", "%m/%d/%y", "%y/%m/%d", and "%y/%d/%m", depending on date_order() | (since C++11) |
The parsed date 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 date 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 date.
Notes
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.
Example
Run this code
#include <iostream> #include <locale> #include <sstream> #include <iterator> #include <ctime> void try_get_date(const std::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; std::istreambuf_iterator<char> ret = std::use_facet<std::time_get<char>>(str.getloc()).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("20130201"); }
Output:
Parsing the date out of '02/01/2013' in the locale en_US.utf8 Day: 1 Month: 2 Year: 2013 Parsing the date out of '02-01-2013' in the locale en_US.utf8 Parse failed. Unparsed string: -01-2013 Parsing the date out of '20130201' in the locale ja_JP.utf8 Day: 1 Month: 2 Year: 2013
See also
(C++11) |
parses a date/time value of specified format (function template) |