">&gt;</span> <span class="emphasis"><em><span class="identifier">unspecified</span></em></span> <a class="link" href="counting_iterator.html#idp53393520-bb"><span class="keyword">operator</span><span class="special">[</span><span class="special">]</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">Expr</span> <span class="special">&amp;</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>

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