title: Where I can find definitions of vector types (uchar3, float3, uint2, and alike)?
body: <p>For now I know that such types exist, I know what fields they have, but I couldn't find a definitions for them. I.e. I found:</p>
  
  <pre><code>typedef __device_builtin__ struct uint2 uint2;
  </code></pre>
  
  <p>But this leaves all the questions I have intact -- what about their constructors? What about operators? And so on.</p>
  
  <p>So, are the definitions (real ones) for those types published somewhere? I wouldn't like to reinvent the wheel especially not optimized (starting how to init such structure).</p>