id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
3967	Parsing dates using date_input_facet accepts wrong input	anonymous	az_sw_dude	"Hi!

I got no answer on the ML, but I consider this a bug.
With the code below I try to automagically determine the date
format found in input files. I'd expect the code below to find the
date format ""%d.%m.%Y"" for ""05.02.2008"", but I got surprised by 
obtaining ""%m/%d/%Y"". 
It seems like date accepts '.' where I said ""expect '/'"", so I think
this should be changed. 


#include <boost/assign/list_of.hpp>

#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/date_time/gregorian/gregorian.hpp>
#include <boost/date_time/local_time/local_time.hpp>
#include <boost/foreach.hpp>
#include <boost/algorithm/string.hpp>

#include <string>
#include <list>

inline std::string determine_date_format(std::string const & s)
{
    using namespace boost::assign;
    using namespace boost::gregorian; 

    std::list<std::string> possible_formats = // TODO: add others here!
        list_of (""%Y-%m-%d"")(""%Y/%m/%d"")(""%m/%d/%Y"")(""%d.%m.%Y""); 

    bool inform_user = false;

    BOOST_FOREACH(std::string const & format, possible_formats)
    {
        if (inform_user)
        {
            std::cout << ""Trying format '"" << format << ""' ..."" << std::endl; 
        } 

        try
        {
            date_input_facet * input_facet = 
                new date_input_facet(format.c_str()); 
            std::istringstream iss(s); 
            iss.imbue(std::locale(iss.getloc(), input_facet)); 
            date d(not_a_date_time); 

            iss >> d; 
            if (!iss.fail() && (!d.is_not_a_date()))
            {
                return format;
            }

            std::cout << ""WARNING: date format '"" << format 
                      << ""' does not match '"" << s << ""'."" << std::endl;   
            inform_user = true;
        }
        catch(...)
        {
        }
    }

    std::cout << ""WARNING: date format not recognized. ""
              << ""Please reconfigure your measurement equipment ""
              << ""to ISO standard output!"" 
              << std::endl;

    return """";
}

int main()
{
    std::string the_date = ""05.02.2008""; 
    std::string format = determine_date_format(the_date);
    std::cout << the_date << "" has date-time-format "" 
              << format << std::endl;    
    return 0;
}

"	Bugs	new	Boost 1.43.0	date_time	Boost 1.37.0	Showstopper