="keyword">const</span><span class="special">;</span></pre>Get the entry with the key. Throws if it does not exist. </li>
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<pre class="literallayout"><a class="link" href="basic_environment/entry_type.html" title="Struct template entry_type">entry_type</a> <a name="idp51510352-bb"></a><span class="keyword">operator</span><span class="special">[</span><span class="special">]</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">string_type</span>