title: Expand Rect by 100px
body: <p>I use OpenCV 2.4.4 in C++ and have Rect I want to make bigger by x pixels. OpenCV documentation provides <a href="http://opencv.willowgarage.com/documentation/cpp/basic_structures.html" rel="nofollow">nice example</a> (look for "expanding or shrinking rectangle by a certain amount") how to use this in image <a href="http://opencv.willowgarage.com/documentation/cpp/_images/math/a6f41031fb2ccaa600520bcbde63a8a9fcff9edf.png" rel="nofollow">http://opencv.willowgarage.com/documentation/cpp/_images/math/a6f41031fb2ccaa600520bcbde63a8a9fcff9edf.png</a></p>
  
  <p>Cool. Only problem I do not know how to enter this in actual C++ code. I tried:</p>
  
  <p>Rect rect=oldrect+-10;
  Rect rect=oldrect-+10;
  and 
  Rect rect=oldrect±10; (I copied this symbol from <a href="http://en.wikipedia.org/wiki/Plus-minus_sign" rel="nofollow">http://en.wikipedia.org/wiki/Plus-minus_sign</a> to be sure. </p>
  
  <p>I get ugly errors on any of them.</p>
  
  <p>Can someone please explain, what is that clever symbol I should use and was impossible to include inside HTML, so it is embedded as image.</p>