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<title>Issue 1003: Require more useful headers for freestanding implementations</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#NAD">NAD</a> status.</em></p>
<h3 id="1003"><a href="lwg-closed.html#1003">1003</a>. Require more useful headers for freestanding implementations</h3>
<p><b>Section:</b> 16.4.2.5 <a href="https://wg21.link/compliance">[compliance]</a> <b>Status:</b> <a href="lwg-active.html#NAD">NAD</a>
 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-11 <b>Last modified:</b> 2016-01-28</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#compliance">issues</a> in [compliance].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#NAD">NAD</a> status.</p>
<p><b>Discussion:</b></p>

<p><b>Addresses JP 23 [CD1]</b></p>

<p>
There is a freestanding implementation including
<code>&lt;type_traits&gt;</code>, <code>&lt;array&gt;</code>,
<code>&lt;ratio&gt;</code>, lately added to Table 13, C++ library headers.
Programmers think them useful and hope that these headers are also added
to Table 15, C++ headers for freestanding implementations, that shows
the set of headers which a freestanding implementation shall include at
least.
</p>

<p><b>Original proposed resolution</b></p>

<p>
Add <code>&lt;type_traits&gt;</code>, <code>&lt;array&gt;</code>,
<code>&lt;ratio&gt;</code> to Table 15.
</p>

<p><i>[
Summit:
]</i></p>


<blockquote>
<p>
 The <code>&lt;array&gt;</code> header has far too many dependencies to require for a
free-standing implementation.
</p>
<p>
The <code>&lt;ratio&gt;</code> header would be useful, has no dependencies, but is not
strictly necessary.
</p>
<p>
The <code>&lt;type_traits&gt;</code> header is fundamentally a core language facility with a
library interface, so should be supported.
</p>

<p>
(it is anticipated the resolution will come via an update to paper
<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2814.pdf">N2814</a>)
(see also LWG <a href="lwg-closed.html#833" title="Freestanding implementations header list needs review for C++0x (Status: NAD)">833</a><sup><a href="https://cplusplus.github.io/LWG/issue833" title="Latest snapshot">(i)</a></sup>)
</p>
</blockquote>

<p><i>[
Batavia (2009-05):
]</i></p>

<blockquote><p>
Leave in Review status pending a paper on freestanding implementations
by Martin Tasker.
</p></blockquote>

<p><i>[
2009-07 Frankfurt:
]</i></p>


<blockquote>
<p>
Move this to NAD.
</p>
<p>
We considered all of the listed headers, and found a compelling case
only for the inclusion of <code>&lt;type_traits&gt;</code> in the list of headers required
of a freestanding implementation.
</p>
<p>
See Martin Tasker's paper 
<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2932.pdf">Fixing Freestanding</a>
which provides the wording to include <code>&lt;type_traits&gt;</code> into freestanding
implementations.
</p>
</blockquote>



<p id="res-1003"><b>Proposed resolution:</b></p>
<p>
Add <code>&lt;type_traits&gt;</code> to Table 15.
</p>





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