><span class="identifier">what</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>Returns a string with a description of the error. </li>
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<pre class="literallayout"><span class="keyword">const</span> <span class="identifier">context</span> <span class="special">*</span> <a name="idm45152240677088-bb"></a><span class="identifier">get_context_ptr</span><span class="special">(</span><span class="special"