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    CWG Issue 2502</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="2502"></A><H4>2502.
  
Unintended declaration conflicts in nested statement scopes
</H4>
<B>Section: </B>6.4.3&#160; [<A href="https://wg21.link/basic.scope.block">basic.scope.block</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD6
 &#160;&#160;&#160;

 <B>Submitter: </B>Jens Maurer
 &#160;&#160;&#160;

 <B>Date: </B>2021-08-26<BR>


<P>[Accepted at the February, 2022 meeting.]</P>



<P>The changes of P1787R6 inadvertently made constructs like</P>

<PRE>
  if (int a = 1)
    if (int a = 1)
      ...
</PRE>

<P>ill-formed.</P>

<P><B>Proposed resolution (September, 2021):</B></P>

<P>Change 6.4.3 [<A href="https://wg21.link/basic.scope.block#2.2">basic.scope.block</A>] bullet 2.2 as follows:</P>

<BLOCKQUOTE>

<P> If a declaration whose target scope is the block
scope <I>S</I> of a</P>

<UL>
<LI><P>
<I>compound-statement</I> of
a <I>lambda-expression</I>, <I>function-body</I>,
or <I>function-try-block</I>,</P></LI>

<LI><P>substatement of a selection or iteration statement
<INS>that is not itself a selection or iteration
statement</INS>, or</P></LI>

<LI>

<P>
<I>handler</I> of a <I>function-try-block</I>
</P>
</LI>

</UL>

<P>potentially conflicts with a declaration whose target scope
is the parent scope of <I>S</I>, the program is ill-formed.</P>

</BLOCKQUOTE>

<P>(See
<A HREF="https://github.com/cplusplus/draft/pull/4843">editorial
issue 4843</A>.)
</P>

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