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<title>Issue 2187: vector&lt;bool&gt; is missing emplace and emplace_back member functions</title>
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<p><em>This page is a snapshot from the LWG issues list, see the <a href="lwg-active.html">Library Active Issues List</a> for more information and the meaning of <a href="lwg-active.html#C++14">C++14</a> status.</em></p>
<h3 id="2187"><a href="lwg-defects.html#2187">2187</a>. <code>vector&lt;bool&gt;</code> is missing <code>emplace</code> and <code>emplace_back</code> member functions</h3>
<p><b>Section:</b> 23.3.14 <a href="https://wg21.link/vector.bool">[vector.bool]</a> <b>Status:</b> <a href="lwg-active.html#C++14">C++14</a>
 <b>Submitter:</b> Nevin Liber <b>Opened:</b> 2012-09-21 <b>Last modified:</b> 2016-01-28</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View other</b> <a href="lwg-index-open.html#vector.bool">active issues</a> in [vector.bool].</p>
<p><b>View all other</b> <a href="lwg-index.html#vector.bool">issues</a> in [vector.bool].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#C++14">C++14</a> status.</p>
<p><b>Discussion:</b></p>

<p>
It should have them so that it more closely matches the <code>vector&lt;T&gt;</code> interface, as this helps when 
writing generic code.
</p>

<p><i>[2012, Portland: Move to Tentatively Ready]</i></p>

<p>
Question on whether the variadic template is really needed, but it turns out to be needed to support
<code>emplace</code> of no arguments.
</p>

<p><i>[2013-04-20 Bristol]</i></p>




<p id="res-2187"><b>Proposed resolution:</b></p>
<p>This wording is relative to N3376.</p>

<ol>
<li><p>Change the class template <code>vector&lt;bool&gt;</code> synopsis, 23.3.14 <a href="https://wg21.link/vector.bool">[vector.bool]</a> p1, as indicated:</p>
<blockquote><pre>
namespace std {
  template &lt;class Allocator&gt; class vector&lt;bool, Allocator&gt; {
  public:
    [&hellip;]
    <i>// modifiers:</i>
    <ins>template &lt;class... Args&gt; void emplace_back(Args&amp;&amp;... args);</ins>
    void push_back(const bool&amp; x);
    void pop_back();
    <ins>template &lt;class... Args&gt; iterator emplace(const_iterator position, Args&amp;&amp;... args);</ins>
    iterator insert(const_iterator position, const bool&amp; x);
    [&hellip;]
  };
}
</pre></blockquote>
</li>
</ol>






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