Re: octave-image requires c++11

[Orion Poplawski]

On 07/30/2015 12:15 PM, Carnë Draug wrote:
> On 30 July 2015 at 04:57, John W. Eaton <address@hidden> wrote:
>> On 07/29/2015 10:48 PM, Orion Poplawski wrote:
>>>
>>> It appears that octave-image 2.4.0 requires c++11:
>>>
>>> checking whether g++ supports C++11 features by default... no
>>> checking whether g++ supports C++11 features with -std=gnu++11... no
>>> checking whether g++ supports C++11 features with -std=gnu++0x... no
>>> checking whether g++ supports C++11 features with -std=c++11... no
>>> checking whether g++ supports C++11 features with -std=c++0x... no
>>> configure: error: *** A compiler with support for C++11 language
>>> features is required.
>>>
>>> While I can very much sympathize with wanting to have progress, just
>>> note that it is a bit trickier (though not impossible) to get access to
>>> a C++11 compiler on RHEL6.  Just something I wanted to note.
>>
>>
>> Yeah, I'm not a fan of this choice either.  At the very least, it would be
>> helpful to provide some kind of fallback code.  Or, if that causes too much
>> of a maintenance burden, then it would be much better to only disable those
>> features that actually require C++11 and at least allow a subset of the
>> package to build.
>>
> 
> I don't see the point of coding a workaround.  I might as well use only the
> workaround then.  It is possible to code without std::function, I did that
> for a while, but it makes the code messier and I'm not interested on that.
> 
> At the moment, C++11 is mainly used by connectivity class, which is a C++
> class for the image package, not a function.  It is used by:
> 
>   * bwlabeln
>   * bwlabel
>   * bwperim
>   * bwconncomp
>   * imreconstruct
>   * watershed
>   * conndef
>   * iptcheckconn
>   * bwfill
> 
> These functions then get used by:
> 
>   * regionprops
>   * bwboundaries
>   * bwpropfilt
>   * imregionalmax
>   * imregionalmin
>   * bwmorph
>   * bwclearborder
>   * bwselect
> 
> There are other functions which then make use of these.  Not having C++11
> will disable a large chunk of the image package, pretty much all of the
> mathematical morphology functions.  And I don't think a function needs to
> be aware that one of its dependencies needs C++11 to work properly.
> It's not a function that needs it, it's one of the classes of the package.
> 
> It appears that the minimum required gcc version is 4.5.  That was released
> more than 5 years ago.  Both latest stable debian and centOS releases
> support it so I don't think it's a bad target.  Anyone with older systems
> can:
> 
>   1) install an older version of the image package;
>   2) revise their need for the image package 2.4;
>   3) upgrade their distribution;
>   4) build a newer gcc themselves;
>   5) employ someone to code a workaround for them.

So I managed to compile octave-image without too much trouble using the gcc
4.9.2 compiler provided by the devtoolset-3 SCL.  However, I'm a little
worried about having octave and octave-image compiled with different
compilers.  Is there a test-suite for the image package that I could run?

Thanks,
  Orion


-- 
Orion Poplawski
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NWRA, Boulder/CoRA Office             FAX: 303-415-9702
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