limits</span><span class="special">&lt;</span><span class="identifier">UnsignedInt</span><span class="special">&gt;::</span><span class="identifier">digits</span> <span class="special">&gt;=</span> <span class="number">16</span><span class="special">,</span> <span class="string">"Template argument UnsignedInt must have at least 16 bits precision."</span><span class="special">)</span>
   <span class="identifier">BOOST_STATIC_ASSERT_MSG</span><span class="special">(</span><span class="identifier">std</span><s