XXGRAPH</div>
<div class="line"><a name="l00026"></a><span class="lineno">   26</span>&#160;{</div>
<div class="line"><a name="l00027"></a><span class="lineno">   27</span>&#160;    <span class="comment">//STRING ERROR CONST EXPRESSION</span></div>
<div class="line"><a name="l00028"></a><span class="lineno">   28</span>&#160;    constexpr <span class="keywordtype">char</span> ERR_NO_DIR_OR_UNDIR_EDGE[] = <span class="stringliteral">&quot;Edge are neither Directed neither Undirected&quot;</span>;</div>
<div 