Re: [boost] Are result_of tests correct?

From: Douglas Gregor (doug.gregor_at_[hidden])
Date: 2007-01-06 12:52:11

On Jan 6, 2007, at 9:54 AM, Peter Dimov wrote:

> Yuval Ronen wrote:
>
>> Wouldn't the result_of library be completely useless once typeof and
>> other stuff like that be introduced into the language? Is the
>> result_of library just a temporary patch accepted to tr1 only until
>> C++0x?
>
> It would be nice if the answers to these questions turn out to be  
> yes and
> yes, in no particular order. But there are indications that  
> decltype won't
> be quite what it needs to be in order to render result_of useless.  
> We'll
> have to wait and see.

The intent was "yes" and "yes", but in the end we found that  
result_of still has some notational advantages over decltype in many  
cases. If anything is going to make result_of useless, it would be  
the introduction of the "Callable" concept, which gives the same  
information in addition to type-safety guarantees.

If decltype does not end up with the right semantics to make  
implementing result_of trivial, I suspect it will be over the dead  
bodies of the majority of the Library Working Group. The reason we  
have "decltype" and not "typeof" is because someone wanted typeof to  
strip references...

   Cheers,
   Doug