Do-while statement in OpenCV C++ with xml

[AccinsgAk]

I am trying to read data from an xml file using OpenCV.The data is from a video recording.What I want to do is write a "do-while" statement that basically says"Do nothing while there is no data from that frame"I tried using FileNode::empty() in the while statement, but I don't think I'm understanding the syntax properly, because I keep getting the error "Call to non-static member function without an object argument"I'm a complete novice to programming, so I really have no idea how I should be structuring the statement correctly. I've been going through the tutorials and the reference manual for OpenCV, but it's not clearing anything up for me.Below is an except from the very beginning of the xml file:\[code\]<frame_00000> <pose type_id="opencv-matrix"> <rows>0</rows> <cols>0</cols> <dt>u</dt> <data></data></pose> <expertCode>3</expertCode> <autoCode>-1</autoCode></frame_00000><frame_00001> <pose type_id="opencv-matrix"> <rows>0</rows> <cols>0</cols> <dt>u</dt> <data></data></pose> <expertCode>0</expertCode> <autoCode>-1</autoCode></frame_00001><frame_00002> <pose type_id="opencv-matrix"> <rows>6</rows> <cols>1</cols> <dt>d</dt> <data> 9.6603986167822176e-02 2.7534827334102827e-02 -7.9839974858475181e-03 2.9772357539313782e+02 2.6446663460538508e+02 1.5645098067258549e+00</data></pose> <expertCode>0</expertCode> <autoCode>0</autoCode></frame_00002>\[/code\]Basically, what I want it to do is look at each of the frame nodes, determine whether there's any data in them, and ignore them if there isn't.Any tips on the syntax of the FileNode::empty() statement would be appreciated.