="identifier">string_type</span> <span class="special">&amp;</span> key<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>Find a variable by its name. </li>
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<pre class="literallayout"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="idp51496512-bb"></a><span class="identifier">count</span><span class="special">(</span><span class="keyword">const</span> <span class="identif