title: How can I assign a default value to a structure in a C++ function?
body: <p>I have a structure:</p>
  
  <pre><code>typedef struct {
     double x,y,z;
  } XYZ;
  </code></pre>
  
  <p>I want to define a function like this:</p>
  
  <pre><code>double CalcDisparity(XYZ objposition, 
                       XYZ eyeposition, 
                       double InterOccularDistance = 65.0)
  </code></pre>
  
  <p>But I can't seem to find a way to assign a default value to eyeposition.  How can I do this in C++?</p>