<HTML>
<HEAD>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<TITLE>
    CWG Issue 879</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="879"></A><H4>879.
  
Missing built-in comparison operators for pointer types
</H4>
<B>Section: </B>12.5&#160; [<A href="https://wg21.link/over.built">over.built</A>]
 &#160;&#160;&#160;

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

 <B>Submitter: </B>Daniel Kr&#252;gler
 &#160;&#160;&#160;

 <B>Date: </B>25 April, 2009<BR>


<P>[Voted into WP at October, 2009 meeting.]</P>



<P>12.5 [<A href="https://wg21.link/over.built#15">over.built</A>] paragraph 15 restricts the built-in comparison
operators to</P>

<BLOCKQUOTE>

every <I>T</I>, where <I>T</I> is an enumeration type or pointer to
effective object type

</BLOCKQUOTE>

<P>This omits both pointers to function types and pointers to void.</P>

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

<OL>
<LI><P>Add a new paragraph following 7.6.9 [<A href="https://wg21.link/expr.rel#2">expr.rel</A>] paragraph 2:
</P></LI>

<BLOCKUOTE>

<INS>Pointers to <TT>void</TT> (after pointer conversions) can be
compared, with a result defined as follows: If both pointers represent
the same address or are both the null pointer value, the result is
<TT>true</TT> if the operator is <TT>&lt;=</TT> or <TT>&gt;=</TT> and
<TT>false</TT> otherwise; otherwise the result is unspecified.</INS>

</BLOCKUOTE>

<LI><P>Change 7.6.10 [<A href="https://wg21.link/expr.eq#1">expr.eq</A>] paragraph 1 as follows:</P></LI>

<BLOCKQUOTE>

...Pointers <DEL>to objects or functions</DEL> of the same type (after
pointer conversions) can be compared for equality...

</BLOCKQUOTE>

<LI><P>Change 12.5 [<A href="https://wg21.link/over.built#15">over.built</A>] paragraph 15 as follows:</P></LI>

For every <TT>T</TT>, where <TT>T</TT> is an enumeration type<DEL>
or</DEL><INS>, a</INS> pointer <DEL>to effective object</DEL> type,
<INS>or <TT>std::nullptr_t</TT>,</INS> there exist candidate operator
functions of the form...

</OL>

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