Re: [Boost-users] date_time:

From: __PPS__ (i-love-spam_at_[hidden])
Date: 2005-10-24 11:51:20

Jeff Garland wrote:

>>Are there better conversion functions from ISO date format (calendar,
>> ordinal, week dates) in basic and/or extended format? Should 
>>conversion from invalid iso date like "20050231" fail or produce 
>>same results as date(2005,02,31). (I know that it produces the same 
>>results, but is it right to convert invalid iso date representation 
>>to valid date?)
> 
> 
> In 1.33 the following code produces 2 exceptions:
> 
>   try {
>     std::string ds("20050231");
>     date d = from_undelimited_string(ds);
>     std::cout << d << std::endl;
>   }
>   catch(bad_day_of_month& e) {
>     std::cout << "exception: " << e.what() << std::endl;
>   }
> 
>   try {
>     date d(2005,02,31);
>     std::cout << d << std::endl;
>   }
>   catch(bad_day_of_month& e) {
>     std::cout << "exception: " << e.what() << std::endl;
>   }

Ok, I was wrong that they produce the same results, but I was wrong 
cause I didn't expect that date(2005,02,31) checks date correctness 
similar to from_undelimited_string("20050231"); which does not. Did you 
try to run these two examples? I got this output (v 1.33):
2005-Mar-03
exception: Day of month is not valid for year

>>Another thing I noted, some conversion functions accept const 
>>std::string &, but most of them accept plain std::string, isn't 
>>better to convert all of them to constant references???
> 
> 
> Sure unless they copy the string anyway, which I don't think they do.

from_undelimited_string(std::string) does exactly the same as 
date_from_iso_string(const std::string &)

> 
>>If anybody interested, I wrote such function that accepts iso date 
>>string in any of the above mentioned 6 combinations and returns 
>>date. It runs 90-100 times faster than equivalent 
>>date_from_iso_string from boost. And yes, it does make sure that 
>>"20050229" fails
> 
> 
> As I said above, contributions always welcome.

this is my code that converts iso date string to gregorian::date:
http://tinyurl.com/cvqhb

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