dentifier">FwdIter</span><span class="special">,</span> <span class="identifier">FwdIter</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>Returns a sort key for the character sequence designated by the iterator range [F1, F2) such that if the character sequence [G1, G2) sorts before the character sequence [H1, H2) when character case is not considered then v.transform_primary(G1, G2) &lt; v.transform_primary(H1, H2).</p>
<div class="note"><table 