Re: [Boost-bugs] [Boost C++ Libraries] #1315: iterator_adaptor does not work with incomplete Value types

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #1315: iterator_adaptor does not work with incomplete Value types
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-04-24 23:59:28

#1315: iterator_adaptor does not work with incomplete Value types
--------------------------------------+-------------------------------------
  Reporter:  joaquin                  |       Owner:  witt    
      Type:  Feature Requests         |      Status:  new     
 Milestone:  To Be Determined         |   Component:  iterator
   Version:  Boost Development Trunk  |    Severity:  Problem 
Resolution:                           |    Keywords:          
--------------------------------------+-------------------------------------
Changes (by dave):

  * owner:  dave => witt
  * status:  assigned => new

Comment:

 Replying to [comment:4 joaquin]:
 > > I think your analysis is correct, but my question to you is: why
 should this be considered a bug?
 >
 >
 > Because T*, which is the type upon which iterators are modelled, can be
 instantiated on incomplete types.

 Technically, T* can't be instantiated, since it isn't a template.

 > I've checked section 24.1 of the standard and this requirement does not
 seem to be explicitly stated, but IMHO it's a nice feature to have, given
 that 24.1.2 recognized iterators as an abstraction of pointers. FWIW, I
 first encountered the problem in the context of a real situation.

 Exactly, a nice feature to have.  I think this is a feature request...
 which is why you've labelled it as such.  OK, objection withdrawn ;-)

 >
 > > I can only think of one way around it, and that's to templatize
 operator[]
 >
 >
 > Correct. Please see
 >
 > http://lists.boost.org/Archives/boost/2007/10/128738.php

 >
 > where I propose a possible implementation of the workaround.

 Thomas: I guess since operator[] has to be a member function, we wouldn't
 gain anything by enable-if'ing it?

-- 
Ticket URL: <http://svn.boost.org/trac/boost/ticket/1315#comment:5>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.