lass="lineno">    1</span>&#160;<span class="preprocessor">#ifndef PAIR_H90</span></div>
<div class="line"><a name="l00002"></a><span class="lineno">    2</span>&#160;<span class="preprocessor"></span><span class="preprocessor">#define PAIR_H90 1</span></div>
<div class="line"><a name="l00003"></a><span class="lineno">    3</span>&#160;<span class="preprocessor"></span>    </div>
<div class="line"><a name="l00004"></a><span class="lineno">    4</span>&#160;    <span class="keyword">type</span>, public :: <a