word">struct</span> <a class="link" href="has_data_idm45077025167856.html" title="Struct template has_dataset&lt;DataSet0, DataSet1, DataSetTT...&gt;">has_dataset</a><span class="special">&lt;</span><span class="identifier">DataSet0</span><span class="special">,</span> <span class="identifier">DataSet1</span><span class="special">,</span> <span class="identifier">DataSetTT</span><span class="special">...</span><span class="special">&gt;</span> <span class="special">:</span> <span class="keyword">public</spa