title: 'cv': a namespace with this name does not exist while building (VS 2015, OpenCV 3.2)
body: <p>While building a simple OpenCV app in VS2015 I am getting error <code>'cv': a namespace with this name does not exist while building</code> while I believe I did all the required steps to configure OpenCV for VS (using this article as reference <a href="http://opencv-srf.blogspot.com/2013/05/installing-configuring-opencv-with-vs.html" rel="nofollow noreferrer">http://opencv-srf.blogspot.com/2013/05/installing-configuring-opencv-with-vs.html</a>)</p>
  
  <p>Beginning of the class is very simple</p>
  
  <pre><code>#include "opencv2/imgcodecs.hpp"
  #include "opencv2/highgui.hpp"
  #include "opencv2/stitching.hpp"
  #include "opencv2/core/core.hpp"
  #include "stdafx.h"
  
  using namespace std;
  using namespace cv;
  </code></pre>
  
  <p>Since Visual Studio doesn't throw any errors on #include I assume the configuration in the C/C++ -> General -> Additional Include Directories is correct.</p>
  
  <p>In Linker -> General -> Additional Library Dependencies I have the <code>opencv\build\x64\vc14\build\lib</code> folder added.</p>
  
  <p>In Linker -> Input -> Additional Dependencies I have the following two libs: </p>
  
  <pre><code>opencv_world320.lib
  opencv_world320d.lib
  </code></pre>
  
  <p>There is nothing else in this folder. Folder <code>opencv/build/x64/vc14/bin</code> is added to PATH.</p>
  
  <p>Any suggestions what to check/change is appreciated :)</p>