How can I parse a std::string (YYYY-MM-DD) into a COleDateTime object?

Question

I have a COleDateTime object and I want to parse a date string in the format YYYY-MM-DD.

The string variable, for example, is:

std::string strDate = "2022-07-04";

COleDateTime allows me to use ParseDateTime to parse a string, but I see no way to tell it what format the components of the date string are. In C# I can do such with DateTime.Parse....

https://learn.microsoft.com/en-us/cpp/atl-mfc-shared/reference/coledatetime-class?view=msvc-170#format maybe? — πάντα ῥεῖ, Jul 04 '22 at 11:33
@πάνταῥεῖ No - that is for formatting the date AS a string. My question is about PARSING a string into a date. — Andrew Truckle, Jul 04 '22 at 11:34

score 2 · Answer 1 · answered Jul 04 '22 at 11:53

2

Why not just a simple formatted input.

std::stringstream ss(strDate);
int year, month, day;
char dash;
ss >> year >> dash >> month >> dash >> day;
COleDateTime(year, month, day, 0, 0, 0);

answered Jul 04 '22 at 11:53

Captain Giraffe

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Andrew Truckle · Accepted Answer · 2022-07-04T14:07:29.250

2

Based on the suggestion by @xMRi in the comments I have decided to use:

CString strDutyMeetingDate = CString(tinyxml2::attribute_value(pDutyWeek, "Date").c_str());
int iDay{}, iMonth{}, iYear{};
if(_stscanf_s(strDutyMeetingDate, L"%d-%d-%d", &iYear, &iMonth, &iDay) == 3)
{
    const auto datDutyMeetingDate = COleDateTime(iYear, iMonth, iDay, 0, 0, 0);
}

edited Jul 04 '22 at 14:07

answered Jul 04 '22 at 12:53

Andrew Truckle

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score 1 · Answer 3 · answered Jul 04 '22 at 22:27

COleDateTime::ParseDateTime uses default parameter LANG_USER_DEFAULT, it can be called as

COleDateTime dt;
dt.ParseDateTime("2022-07-04");

Or

dt.ParseDateTime("2022-07-04", VAR_DATEVALUEONLY, LANG_USER_DEFAULT);

"2022-07-04" uses long date format so it should be safe, because it is clear that the year is at the start, and month is expected to be in the middle. I believe any LCID should return 2022-July-4th (I am 60% sure!)

If the date string was short, it could get confused with MM/DD/YY format, but that's not a problem here.

To make the lcid manually, see the English-US example below, although it should not be necessary in this case.

LCID lcid = MAKELCID(MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US), SORT_DEFAULT);

Thanks for your answer. I don't doubt you when you say I can just use the string verbatim. But, since the application supports 50+ languages, and you are only 60% sure ... I have left it as I coded it. — Andrew Truckle, Jul 05 '22 at 07:48

How can I parse a std::string (YYYY-MM-DD) into a COleDateTime object?

3 Answers3