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    CWG Issue 1512</TITLE>
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<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="1512"></A><H4>1512.
  
Pointer comparison vs qualification conversions
</H4>
<B>Section: </B>7.6.9&#160; [<A href="https://wg21.link/expr.rel">expr.rel</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD3
 &#160;&#160;&#160;

 <B>Submitter: </B>Steve Clamage
 &#160;&#160;&#160;

 <B>Date: </B>2012-06-22<BR>


<P>[Moved to DR status at the April, 2013 meeting as paper N3624.]</P>



<P>According to 7.6.9 [<A href="https://wg21.link/expr.rel#2">expr.rel</A>] paragraph 2, describing
pointer comparisons,</P>

<BLOCKQUOTE>

Pointer conversions (7.3.12 [<A href="https://wg21.link/conv.ptr">conv.ptr</A>]) and qualification
conversions (7.3.6 [<A href="https://wg21.link/conv.qual">conv.qual</A>]) are performed on pointer
operands (or on a pointer operand and a null pointer constant, or on
two null pointer constants, at least one of which is non-integral) to
bring them to their <I>composite pointer type</I>.

</BLOCKQUOTE>

<P>This would appear to make the following example ill-formed,</P>

<PRE>
  bool foo(int** x, const int** y) {
     return x &lt; y;  //<SPAN CLASS="cmnt"> valid ?</SPAN>
  }
</PRE>

<P>because <TT>int**</TT> cannot be converted to <TT>const int**</TT>,
according to the rules of 7.3.6 [<A href="https://wg21.link/conv.qual#4">conv.qual</A>] paragraph 4.  This
seems too strict for pointer comparison, and current implementations
accept the example.</P>

<P><B>Proposed resolution (November, 2012):</B></P>

<P>The proposed wording is found in document N3478.</P>

<P>(This resolution also resolves <A HREF="583.html">issue 583</A>.)</P>

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