>Example</span><span class="o">&lt;&gt;</span> <span class="n">get</span><span class="p">(</span><span class="kt">size_t</span> <span class="n">index</span><span class="p">)</span> <span class="k">override</span><span class="p">;</span>

    <span class="c1">// The size of the dataset</span>
    <span class="n">c10</span><span class="o">::</span><span class="n">optional</span><span class="o">&lt;</span><span class="kt">size_t</span><span class="o">&gt;</span> <span class="n">size</span><span class="p">()</s