[boost] Re: Imminent Code Breakage

From: Roland Richter (roland_at_[hidden])
Date: 2003-06-05 06:03:27

David Abrahams wrote:
> 
> This is going to break every boost library and every user which is
> depending on the current CVS version of iterator_adaptors.  The new
> adaptors are so much better designed and easier to use that making the
> transition should be cake, but before I do anything drastic I want to
> hear how loud the pre-emptive screaming is ;-)
> 
> Objections?
> 

  No objections, Your Honour :-) ... just two remarks.

  I tried to update the view library (uses iterator_adaptors a lot),
  and generally it turned out to be straight-forward. However:

  +  permutation_iterator is missing - when will it be due?

     (It would be easier to "port" derived iterator types if there was
      a detailed how-to somewhere.)

  + Problems with MSVC++ 7.0 (as ever) and dereference (I guess this is
    a problem with default types). Demonstrated with reverse_iterator:

   int numbers[] = { 1,2,3,4,5,6,7 };
   const int N = sizeof(numbers)/sizeof(int);
   std::vector<int> v( numbers, numbers + N );

   typedef boost::reverse_iterator< std::vector<int>::iterator >
           reverse_iterator;
   reverse_iterator rit( v.begin() );

   if( *rit == v[0] ) // Does not compile
   { }

   if( v[0] == *rit ) // Does not compile
   { }

- Roland