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    CWG Issue 1767</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="1767"></A><H4>1767.
  
Scoped enumeration in a <TT>switch</TT> statement
</H4>
<B>Section: </B>8.5.3&#160; [<A href="https://wg21.link/stmt.switch">stmt.switch</A>]
 &#160;&#160;&#160;

 <B>Status: </B>C++14
 &#160;&#160;&#160;

 <B>Submitter: </B>Canada
 &#160;&#160;&#160;

 <B>Date: </B>2013-09-23<BR><BR>


<A href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3903.html#CA8">N3690 comment
  CA&#160;8<BR></A>

<P>[Moved to DR at the February, 2014 meeting.]</P>

<P>The description of the <TT>switch</TT> statement and case labels in
8.5.3 [<A href="https://wg21.link/stmt.switch#2">stmt.switch</A>] paragraph 2 apply integral promotions to the
condition value and refer to the &#8220;promoted type&#8221; of the
condition.  However, the integral promotions (7.3.7 [<A href="https://wg21.link/conv.prom">conv.prom</A>])
do not describe the result when they are applied to a scoped enumeration
value.</P>

<P><B>Proposed resolution (September, 2013):</B></P>

<P>Change 8.5.3 [<A href="https://wg21.link/stmt.switch#2">stmt.switch</A>] paragraph 2 as follows:</P>

<BLOCKQUOTE>

<P>The condition shall be of integral type, enumeration type, or class
type. If of class type, the condition is contextually implicitly converted
(7.3 [<A href="https://wg21.link/conv">conv</A>]) to an integral or enumeration
type. <DEL>Integral promotions are performed.</DEL> <INS>If the (possibly
converted) type is subject to integral promotions
(7.3.7 [<A href="https://wg21.link/conv.prom">conv.prom</A>]), the condition is converted to the promoted
type.</INS> Any statement within the <TT>switch</TT> statement can be
labeled with one or more case labels as follows:</P>

<UL>
<TT>case</TT> <I>constant-expression</I> <TT>:</TT>
</UL>

<P>where the <I>constant-expression</I> shall be a converted constant
expression (7.7 [<A href="https://wg21.link/expr.const">expr.const</A>]) of
the <DEL>promoted</DEL> <INS>adjusted</INS> type of the switch
condition. No two of the case constants in the same switch shall have the
same value after conversion <DEL>to the promoted type of the switch
condition</DEL>.</P>

</BLOCKQUOTE>

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