[Insight-developers] add operator< and operator> support initk::Index

[Gaetan Lehmann]

On Tue, 07 Jun 2005 15:17:24 +0200, Brad King <brad.king at kitware.com>  
wrote:

> Gaetan Lehmann wrote:
>> On Fri, 03 Jun 2005 18:12:01 +0200, Brad King <brad.king at kitware.com>   
>> wrote:
>>
>>> Miller, James V (Research) wrote:
>>>
>>>> For storage and searching lexicographically, I can understand the   
>>>> motivation.  But since it does not have a geometic meaning, I  
>>>> hesitate  to put it into Index.  The whole purpose of Index to  
>>>> provide a link  between a geometric space and the linear address
>>>> space an image uses to store its pixels.
>>>>  Can we provide function objects (that people will have to go out
>>>> of their way to use) to provide a lexicographically ordering of  
>>>> Indices?
>>>
>>>
>>> Sure:
>>>
>>> template <unsigned int VDimension>
>>> struct IndexLexicographicCompare
>>> {
>>>    bool operator()(Index<VDimension> const& l,
>>>                    Index<VDimension> const& r) const
>>>      {
>>>      ...
>>>      }
>>> };
>>>
>>> std::set< Index<D>, IndexLexicographicCompare<D> > myIndexSet;
>>>
>>  It's a little bit more complicated than with operator<, but it's more   
>> simple than nothing, and the name clearly define for what it is defined  
>> :-)
>>  Is it possible to define the type in Index ? So we can use it like :
>>  std::set< IndexType, IndexType::LexicographicCompare > myIndexSet;
>
> This is now implemented:
>
> /cvsroot/Insight/Insight/Code/Common/itkIndex.h,v  <--  itkIndex.h
> new revision: 1.50; previous revision: 1.49
>
> I've added the typedef in Index also.
>
> -Brad

I use it, and everything is ok :-)
Thanks !

-- 
Gaetan Lehmann <gaetan.lehmann at jouy.inra.fr>
Tel: +33 1 34 65 29 66
Biologie du Développement et de la Reproduction
INRA de Jouy-en-Josas (France)
Web: http://voxel.jouy.inra.fr