New issue from Hewill Kang: "move_iterator::operator* should have conditional noexcept specification"

Author: Dani-Hub

xml/issue4115.xml

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+<?xml version='1.0' encoding='utf-8' standalone='no'?>
+<!DOCTYPE issue SYSTEM "lwg-issue.dtd">
+
+<issue num="4115" status="New">
+<title><tt>move_iterator::operator*</tt> should have conditional <tt>noexcept</tt> specification</title>
+<section><sref ref="[move.iter.elem]"/></section>
+<submitter>Hewill Kang</submitter>
+<date>03 Jul 2024</date>
+<priority>99</priority>
+
+<discussion>
+<p>
+For <tt>move_iterator</tt>, dereferencing it is actually equivalent to applying <tt>iter_move</tt> to it.
+<p/>
+However, unlike the latter, <tt>move_iterator</tt>'s dereference operator lacks a <tt>noexcept</tt> 
+specification, which seems to be an oversight given that the standard goes to such great lengths to 
+preserve the noexceptness of <tt>iter_move</tt>, and the main purpose of <tt>move_iterator</tt> is 
+precisely to apply <tt>iter_move</tt> to the underlying iterator via dereferencing.
+</p>
+</discussion>
+
+<resolution>
+<p>
+This wording is relative to <paper num="N4981"/>.
+</p>
+
+<ol>
+<li><p>Modify <sref ref="[move.iterator]"/> as indicated:</p>
+
+<blockquote><pre>
+namespace std {
+  template&lt;class Iterator&gt;
+  class move_iterator {
+  public:
+    [&hellip;]
+    constexpr reference operator*() const <ins>noexcept(noexcept(ranges::iter_move(current)))</ins>;
+    [&hellip;]
+  };
+}
+</pre></blockquote>
+
+</li>
+
+<li><p>Modify <sref ref="[move.iter.elem]"/> as indicated:</p>
+
+<blockquote>
+<pre>
+constexpr reference operator*() const <ins>noexcept(noexcept(ranges::iter_move(current)))</ins>;
+</pre>
+<blockquote>
+<p>
+-1- <i>Effects</i>: Equivalent to: <tt>return ranges::iter_move(current);</tt>
+</p>
+</blockquote>
+</blockquote>
+
+</li>
+</ol>
+</resolution>
+
+</issue>