<HTML>
<HEAD>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<TITLE>
    CWG Issue 905</TITLE>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<STYLE TYPE="text/css">
  INS { text-decoration:none; font-weight:bold; background-color:#A0FFA0 }
  .INS { text-decoration:none; background-color:#D0FFD0 }
  DEL { text-decoration:line-through; background-color:#FFA0A0 }
  .DEL { text-decoration:line-through; background-color: #FFD0D0 }
  @media (prefers-color-scheme: dark) {
    HTML { background-color:#202020; color:#f0f0f0; }
    A { color:#5bc0ff; }
    A:visited { color:#c6a8ff; }
    A:hover, a:focus { color:#afd7ff; }
    INS { background-color:#033a16; color:#aff5b4; }
    .INS { background-color: #033a16; }
    DEL { background-color:#67060c; color:#ffdcd7; }
    .DEL { background-color:#67060c; }
  }
  SPAN.cmnt { font-family:Times; font-style:italic }
</STYLE>
</HEAD>
<BODY>
<P><EM>This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21
  Core Issues List revision 118b.
  See http://www.open-std.org/jtc1/sc22/wg21/ for the official
  list.</EM></P>
<P>2025-09-28</P>
<HR>
<A NAME="905"></A><H4>905.
  
Explicit defaulted copy constructors and trivial copyability
</H4>
<B>Section: </B>Clause 11&#160; [<A href="https://wg21.link/class">class</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD2
 &#160;&#160;&#160;

 <B>Submitter: </B>Daveed Vandevoorde
 &#160;&#160;&#160;

 <B>Date: </B>27 May, 2009<BR>


<P>[Voted into WP at March, 2010 meeting.]</P>

<P>It is presumably possible to declare a defaulted copy constructor
to be <TT>explicit</TT>.  Should that render a class not trivially
copyable, even though the copy constructor is trivial?  That is,
does being &#8220;trivally copyable&#8221; mean that copy
initialization, and not just direct initialization, is possible?</P>

<P>A related question is whether the specification of triviality
should require that the copy constructor and copy assignment operator
must be public.  (With the advent of &#8220;<TT>=default</TT>&#8221; it
is possible to make them non-public, which was not the case when these
definitions were crafted.)</P>

<P><B>Proposed resolution (October, 2009):</B></P>

<P>This issues is resolved by the resolution of
<A HREF="906.html">issue 906</A>.</P>

<BR><BR>
</BODY>
</HTML>
