On Sat, 23 Apr 2005 10:43:17 +0100, John Maddock wrote
lib. Not to mention that it is almost infinately flexible in terms of how the various types can be streamed. This code will be the standard i/o facet in the 1.33 release.
Jeff, do you mind if I throw a wildcard in here?
Not at all...
Why not drop facets altogether and use a stream format manipulator instead:
std::cout << set_date_format("%Y-%b-%d") << mydate << std::endl;
The format would be stored in the iostreams iword/pword (that's what they're for).
Sure, that would be easy enough to add now, but...
You could still have a facet if you really wanted uses to change the *algorithm* used for io, but I guess what I'm trying to say is that:
algorithms go in facets. configuration data goes in the iostream object itself.
I think there are some other considerations here with date-time. What if you want to replace the short or long strings associated with a month output? Or I want the 'days of the week' be 'day1', 'day2', instead of 'Sun', 'Mon', etc. For these cases I think the strings need to get associated with a facet instead of a fleeting i/o manipulator. So for example //let's change all the short month names to have stars around them const char* const month_short_names[]={"*jan*","*feb*","*mar*", "*apr*","*may*","*jun*", "*jul*","*aug*","*sep*", "*oct*","*nov*","*dec*"}; std::vector<std::basic_string<char> > short_month_names; int main() { using namespace boost::gregorian; std::copy(&month_short_names[0], &month_short_names[12], std::back_inserter(short_month_names)); date_facet* datefacet = new date_facet("%Y %b"); datefacet->short_month_names(short_month_names); std::cout.imbue(std::locale(std::locale::classic(), datefacet)); date d(2005,Apr, 20); std::cout << d << std::endl; //2005 *apr*
Just my 2c worth,
Hope this doesn't cloud things up to much!
No, not at all. I'm sure there will be some tweaking and optimizations of the i/o concepts... Jeff