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<title>Issue 3621: Remove feature-test macro __cpp_lib_monadic_optional</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++23">C++23</a> status.</em></p>
<h3 id="3621"><a href="lwg-defects.html#3621">3621</a>. Remove feature-test macro <code>__cpp_lib_monadic_optional</code></h3>
<p><b>Section:</b> 17.3.2 <a href="https://wg21.link/version.syn">[version.syn]</a> <b>Status:</b> <a href="lwg-active.html#C++23">C++23</a>
 <b>Submitter:</b> Jens Maurer <b>Opened:</b> 2021-10-18 <b>Last modified:</b> 2023-11-22</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View other</b> <a href="lwg-index-open.html#version.syn">active issues</a> in [version.syn].</p>
<p><b>View all other</b> <a href="lwg-index.html#version.syn">issues</a> in [version.syn].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#C++23">C++23</a> status.</p>
<p><b>Discussion:</b></p>
<p>
<a href="https://wg21.link/P0798R8" title=" Monadic operations for std::optional">P0798R8</a> "Monadic operations for <code>std::optional</code>"
created a new feature-test macro <code>__cpp_lib_monadic_optional</code>
for a relatively minor enhancement.
<p/>
We should instead increment the value of the existing
feature-test macro <code>__cpp_lib_optional</code>.
</p>

<p><i>[2022-01-29; Reflector poll]</i></p>

<p>
Set status to Tentatively Ready after eight votes in favour during reflector poll.
</p>

<p><i>[2022-02-10 Approved at February 2022 virtual plenary. Status changed: Tentatively Ready &rarr; WP.]</i></p>



<p id="res-3621"><b>Proposed resolution:</b></p>
<p>
This wording is relative to <a href="https://wg21.link/n4901">N4901</a>.
</p>

<ol>
<li><p>Modify 17.3.2 <a href="https://wg21.link/version.syn">[version.syn]</a> as indicated:</p>

<blockquote>
<pre>
[&hellip;]
<del>#define __cpp_lib_monadic_optional 202110L <i>// also in &lt;optional&gt;</i></del>
[&hellip;]
#define __cpp_lib_optional <del>202106L</del><ins>202110L</ins> <i>// also in &lt;optional&gt;</i>
[&hellip;]
</pre>
</blockquote>
</li>
</ol>





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