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    CWG Issue 1538</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="1538"></A><H4>1538.
  
C-style cast in <I>braced-init-list</I> assignment
</H4>
<B>Section: </B>7.6.19&#160; [<A href="https://wg21.link/expr.assign">expr.assign</A>]
 &#160;&#160;&#160;

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

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

 <B>Date: </B>2012-08-14<BR>


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



<P>According to 7.6.19 [<A href="https://wg21.link/expr.assign#9">expr.assign</A>] paragraph 9,</P>

<BLOCKQUOTE>

The meaning of <TT>x={v}</TT>, where <TT>T</TT> is the scalar type of
the expression <TT>x</TT>, is that of <TT>x=T(v)</TT> except that no
narrowing conversion (9.5.5 [<A href="https://wg21.link/dcl.init.list">dcl.init.list</A>]) is allowed. The
meaning of <TT>x={}</TT> is <TT>x=T()</TT>.

</BLOCKQUOTE>

<P>This definition adds a gratuitous C-style cast to the right-hand
operand, inadvertently allowing such things as base-to-derived
conversions and circumvention of access checking.</P>

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

<P>Change 7.6.19 [<A href="https://wg21.link/expr.assign#9">expr.assign</A>] paragraph 9 as follows:</P>

<BLOCKQUOTE>

The meaning of <TT>x={v}</TT>, where <TT>T</TT> is the scalar type of
the expression <TT>x</TT>, is that of <DEL><TT>x=T(v)</TT> except that
no narrowing conversion (9.5.5 [<A href="https://wg21.link/dcl.init.list">dcl.init.list</A>]) is allowed</DEL>
<INS><TT>x=T{v}</TT></INS>. The meaning of <TT>x={}</TT> is
<TT><DEL>x=T()</DEL> <INS><TT>x=T{}</TT></INS></TT>.

</BLOCKQUOTE>

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