title: Triggering a runtime error within a CUDA kernel
body: <p>In CUDA, we can't throw exceptions; but - we can and do occasionally reach exceptional situations in which we can't proceed, and on the host we would have thrown an exception.</p>
  <p>So, as a second best, we can at least trigger a runtime error to stop doing unreasonable work and indicate that something went wrong.</p>
  <p>What's a good to do so in a CUDA kernel, which:</p>
  <ol>
  <li>Doesn't cause undefined behavior</li>
  <li>Will stop kernel execution once reached</li>
  <li>Will not trigger a compiler warning/error</li>
  </ol>
  <p>?</p>