New issue from Jonathan: "Consider changing how get-domain-early(sndr) works"

Author: Dani-Hub

xml/issue4278.xml

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+<?xml version='1.0' encoding='utf-8' standalone='no'?>
+<!DOCTYPE issue SYSTEM "lwg-issue.dtd">
+
+<issue num="4278" status="New">
+<title>Consider changing how <tt><i>get-domain-early</i>(sndr)</tt> works</title>
+<section>
+<sref ref="[exec.snd.expos]"/>
+</section>
+<submitter>Jonathan Wakely</submitter>
+<date>16 Jun 2025</date>
+<priority>99</priority>
+
+<discussion>
+<p>
+During LWG review of <paper num="P3481R3"/> it was noted that we need to say "except that `sndr` 
+is only evaluated once" because it's used in <tt><i>get-domain-early</i>(sndr)</tt>, but that 
+exposition-only-function doesn't actually use its argument, it only cares about the type, and 
+it default constructs a `Domain` of a type determined by using the type of `sndr`.
+<p/>
+If we had something like:
+</p>
+<blockquote><pre>
+template&lt;class Sender&gt;
+using <i>get-domain-early-t</i> = decltype(<i>get-domain-early</i>(declval&lt;const Sender&amp;&gt;()));
+</pre></blockquote>
+<p>
+then we wouldn't need to use `sndr` twice in expressions that currently use <tt><i>get-domain-early</i>(sndr)</tt>.
+</p>
+</discussion>
+
+<resolution>
+</resolution>
+
+</issue>