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<title>Issue 2870: Default value of parameter theta of polar should be dependent</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++20">C++20</a> status.</em></p>
<h3 id="2870"><a href="lwg-defects.html#2870">2870</a>. Default value of parameter <code>theta</code> of <code>polar</code> should be dependent</h3>
<p><b>Section:</b> 29.4.7 <a href="https://wg21.link/complex.value.ops">[complex.value.ops]</a> <b>Status:</b> <a href="lwg-active.html#C++20">C++20</a>
 <b>Submitter:</b> Japan <b>Opened:</b> 2017-02-03 <b>Last modified:</b> 2021-02-25</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#complex.value.ops">issues</a> in [complex.value.ops].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#C++20">C++20</a> status.</p>
<p><b>Discussion:</b></p>
<p><b>Addresses JP 25</b></p>

<p>Parameter <code>theta</code> of <code>polar</code> has the type of the 
template parameter. Therefore, it needs to change the default initial value 
to <code>T()</code>. The change of the declaration of this function in 
29.4.2 <a href="https://wg21.link/complex.syn">[complex.syn]</a> is accompanied by this change.</p>

<p>
Proposed change:
</p>
<blockquote>
<pre>
template&lt;class T&gt; complex&lt;T&gt; polar(const T&amp; rho, const T&amp; theta = <del>0</del><ins>T()</ins>);
</pre>
</blockquote>

<p><i>[2017-02 pre-Kona]</i></p>

<p>
(twice)
</p>

<p><i>[
2017-06-27 Moved to Tentatively Ready after 7 positive votes on c++std-lib.
]</i></p>



<p id="res-2870"><b>Proposed resolution:</b></p>
<p>This wording is relative to <a href="https://wg21.link/n4659">N4659</a>.</p>

<ol>
<li><p>Modify 29.4.2 <a href="https://wg21.link/complex.syn">[complex.syn]</a>, header <code>&lt;complex&gt;</code> synopsis, as indicated:</p>

<blockquote><pre>
template&lt;class T&gt; complex&lt;T&gt; polar(const T&amp;, const T&amp; = <del>0</del><ins>T()</ins>);
</pre></blockquote>
</li>

<li><p>Modify 29.4.7 <a href="https://wg21.link/complex.value.ops">[complex.value.ops]</a> as indicated:</p>
<blockquote>
<pre>
template&lt;class T&gt; complex&lt;T&gt; polar(const T&amp; rho, const T&amp; theta = <del>0</del><ins>T()</ins>);
</pre>
</blockquote>
</li>
</ol>






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