<p><a href="https://github.com/epatters" class="user-mention">@epatters</a>: i definitely agree that the code you execute should depend on the type of constraint. however, I also agree that variadic templates is black magic, and I think it would be fine to check this information at runtime and branch. </p>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">&mdash;<br />You are receiving this because you are subscribed to this thread.<br />Reply to this email directly or <a href="https://github.com/mlpack/mlpack/issues/578#issuecomment-197626406">view it on GitHub</a><img alt="" height="1" src="https://github.com/notifications/beacon/AJ4bFOT3eoXgPgtbsLPccRPg2OiiTgJFks5puKa7gaJpZM4HyPPr.gif" width="1" /></p>
<div itemscope itemtype="http://schema.org/EmailMessage">
<div itemprop="action" itemscope itemtype="http://schema.org/ViewAction">
  <link itemprop="url" href="https://github.com/mlpack/mlpack/issues/578#issuecomment-197626406"></link>
  <meta itemprop="name" content="View Issue"></meta>
</div>
<meta itemprop="description" content="View this Issue on GitHub"></meta>
</div>