Re: [Boost-users] Boost.MultiArray + iterators

12 Nov 2005

      Hi Dennis,

I don't have access to VC++ 7.1 at the moment and cannot recreate the  
error you are seeing on my platform.  Could you try applying the  
following patch to boost/multi_array/types.hpp and let me know if this  
does the trick?

Thanks,
ron

*** types.hpp	01 Dec 2003 14:07:10 -0500	1.3
--- types.hpp	12 Nov 2005 10:19:48 -0500	
***************
*** 26,32 ****

   // needed typedefs
   typedef std::size_t size_type;
! typedef int index;

   } // namespace multi_array
   } // namespace detail
--- 26,32 ----

   // needed typedefs
   typedef std::size_t size_type;
! typedef std::ptrdiff_t index;

   } // namespace multi_array
   } // namespace detail

On Nov 6, 2005, at 1:29 AM, Dennis Zickefoose wrote:
...
I have a simple two dimensional multi_array that I am trying to copy a
row out of.  This works, but I get a warning about a type conversion
that I would like to get rid of.  Example:
boost::multi_array array(boost::extents[42][42]);
std::vector<double> row(array[0].begin(), array[0].end());
This produces the following warning in VC++ 7.1:
c:\Boost\include\boost-1_33\boost\multi_array\iterator.hpp(149) :
warning C4244: '+=' : conversion from
'boost::detail::multi_array:: 
array_iterator::difference_type'
to
'boost::detail::multi_array:: 
array_iterator::index',
possible loss of data
This is followed by a long string of support messages that ultimately
point to the vector initialization.  Yet the vector is successfully
initialized with the range of values I expect.  So what am I doing  
wrong
here?  I understand that [array.begin(), array.end()) is actually a
range of sub-views, rather than a range of values...is this a side
effect of this distinction?
At the moment, I have replaced that with &array[0][0] to avoid the
warning, but if possible I would like to go with the more reliable
iterator interface in the future.
Any suggestions/advice would be greatly appreciated.
DZJr
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Re: [Boost-users] Boost.MultiArray + iterators

Ronald Garcia