span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Effects: Constructs an empty <code class="computeroutput"><a class="link" href="weak_ptr.html" title="Class template weak_ptr">weak_ptr</a></code>. Postconditions: use_count() == 0. </p>
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<pre class="literallayout"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> Y<span class="special">&gt;</span> <a name="idp50629952-b