an><span class="special">,</span><span class="keyword">true</span><span class="special">&gt;</span></code> if type <code class="computeroutput"><span class="identifier">From</span></code>
        has an explicit conversion from <code class="computeroutput"><span class="identifier">To</span></code>.
      </p>
<p>
        For compilers that support C++11 SFINAE-expressions this trait should "just
        work". Otherwise it inherits from <code class="computeroutput"><span class="identifier">boost</span><span