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<title>Issue 3124: [networking.ts] Unclear how execution_context is intended to store services</title>
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<h3 id="3124"><a href="lwg-active.html#3124">3124</a>. [networking.ts] Unclear how <code>execution_context</code> is intended to store services</h3>
<p><b>Section:</b> 13.7.5 [networking.ts::async.exec.ctx.globals] <b>Status:</b> <a href="lwg-active.html#New">New</a>
 <b>Submitter:</b> Billy O'Neal III <b>Opened:</b> 2018-06-23 <b>Last modified:</b> 2020-09-06</p>
<p><b>Priority: </b>3
</p>
<p><b>View all issues with</b> <a href="lwg-status.html#New">New</a> status.</p>
<p><b>Discussion:</b></p>
<b>Addresses: networking.ts</b>
<p>
<code>make_service</code> and <code>use_service</code> create arbitrary numbers of type <code>Service</code>, a type provided 
by the user, similar to how locale's <code>use_facet</code> works. As a result there's no amount of storage that could 
be reserved inside <code>execution_context</code> to avoid allocating memory. However, there's no allocator support 
here, and <code>make_service</code> is forbidden from throwing allocation related exceptions by 
<a href="https://wg21.link/n4734">N4734</a> [async.exec.ctx.globals]/7.
<p/>
If the intent is for <code>execution_context</code> to allocate memory, are user overloads of <code>operator new</code> 
on type <code>Service</code> intended to be used?
</p>

<p><i>[2018-07-20 Priority set to 3 after reflector discussion]</i></p>

<p><i>[Jonathan provides wording.]</i></p>



<p id="res-3124"><b>Proposed resolution:</b></p>
<p>This wording is relative to the N4762.</p>

<ol>
<li><p>Modify 13.7.5 [networking.ts::async.exec.ctx.globals] p7:</p>
<p>
-7- <i>Throws:</i> <code>service_already_exists</code> if a corresponding service object of type <code>Service::key_type</code> is
already present in the set <ins>, <code>bad_alloc</code>, or an implementation-defined exception when a resource other than memory could
not be obtained. Any exception thrown by the constructor of <code>Service</code></ins>.
</p>
</li>
</ol>





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