<span class="keyword">struct</span> <a class="link" href="extract_or_default.html" title="Struct template extract_or_default">extract_or_default</a> <span class="special">{</span>
<span class="special">}</span><span class="special">;</span></pre></div>
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-<a name="idm46436917541152"></a><h2>Description</h2>
+<a name="idm45554749033360"></a><h2>Description</h2>
<p>The metafunction results in a type that is in form of <code class="computeroutput">T const&</code>, if <code class="computeroutput">T</code> is not an MPL type sequence and <code class="computeroutput">DefaultT</code> is the same as <code class="computeroutput">T</code>, or <code class="computeroutput">value_ref< TypesT, TagT ></code> otherwise, with <code class="computeroutput">TypesT</code> being a type sequence comprising the types from sequence <code class="computeroutput">T</code> and <code class="computeroutput">DefaultT</code>, if it is not present in <code class="computeroutput">T</code> already. </p>
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