Re: [boost] [type_traits] has_equal_to< std::vector<T> > alwaystrue_

Subject: Re: [boost] [type_traits] has_equal_to< std::vector<T> > alwaystrue_
From: John Maddock (boost.regex_at_[hidden])
Date: 2011-10-22 04:25:54

>Thanks for highlighting this major issue. I understand that there is
>nothing to do apart from specializing the traits for those particular
>std classes. This would however not work with user classes. As the
>beta is due on Monday, I believe it is too short to submit a working
>and tested patch. Maybe once the beta is out, you can start to work on
>a proposed contribution?
>Meanwhile, as suggested I will add a warning in the doc.

It's a tricky one, because strictly speaking vector<T> always does have an 
equality operator - it's just that depending upon T it may not compile :-(

There's no general solution to this, because there's no way in the language 
to test whether something does or does not compile - we can only test 
whether it's declared or not.

John.