>first</span><span class="special">;</span>
<span class="identifier">T2</span> <span class="identifier">second</span><span class="special">;</span>

<span class="identifier">pair</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T1</span> <span class="special">&amp;</span> <span class="identifier">nfirst</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T2</span> <span class="special">&amp;</span> <span class="ident