[Insight-developers] Where is 'vnl_abs' declared?

[Huai-Ping Lee]

Hi,

I keep getting the error message when building ITKv4 on a Linux machine:
/home/huai-ping/git/ITK/Modules/Video/Core/include/itkRingBuffer.hxx:227:
error: ‘vnl_abs’ was not declared in this scope
And a grep in the ITK source tree couldn't find the definition of
'vnl_abs' (the line of code above is the only place where 'vnl_abs'
appears). The weird thing is, on my other Linux machine, this error
doesn't come up.

I also saw a similar error on the Dashboard
(http://www.cdash.org/CDash/viewBuildError.php?buildid=1580680):
192>d:\dshbrd\itk\modules\video\core\include\itkRingBuffer.hxx(227) :
error C2668: 'std::abs' : ambiguous call to overloaded function
It looks like in some version, the 'vnl_abs' is replaced with
std::abs, but some compilers are still complaining about it.

-- 
Huai-Ping Lee
Kitware, Inc.