dentifier">n</span><span class="special">;</span>
        <span class="special">}</span>

        <span class="keyword">void</span> <span class="identifier">set_age</span><span class="special">(</span><span class="identifier">Age</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">a</span><span class="special">)</span>
        <span class="special">{</span>
            <span class="identifier">age</span><span class="special">=</span><span class="identifier">a