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    CWG Issue 2351</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="2351"></A><H4>2351.
  
<TT>void{}</TT>
</H4>
<B>Section: </B>7.6.1.4&#160; [<A href="https://wg21.link/expr.type.conv">expr.type.conv</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD5
 &#160;&#160;&#160;

 <B>Submitter: </B>Peter Dimov
 &#160;&#160;&#160;

 <B>Date: </B>2017-06-26<BR>


<P>[Accepted as a DR at the June, 2018 (Rapperswil) meeting.]</P>

<P>According to 7.6.1.4 [<A href="https://wg21.link/expr.type.conv#2">expr.type.conv</A>] paragraph 2,</P>

<BLOCKQUOTE>

If the initializer is a parenthesized single expression, the type
conversion expression is equivalent to the corresponding cast expression
(7.6.3 [<A href="https://wg21.link/expr.cast">expr.cast</A>]). Otherwise, if the type is <I>cv</I>
<TT>void</TT> and the initializer is <TT>()</TT> , the expression is a
prvalue of the specified type that performs no initialization. Otherwise,
the expression is a prvalue of the specified type whose result object is
direct-initialized (9.5 [<A href="https://wg21.link/dcl.init">dcl.init</A>]) with the initializer. For an
expression of the form <TT>T()</TT>, <TT>T</TT> shall not be an array type.

</BLOCKQUOTE>

<P>It seems an oversight that <TT>void{}</TT> is not treated like
<TT>void()</TT>.</P>

<P><B>Proposed resolution, April, 2018:</B></P>

<P>Change 7.6.1.4 [<A href="https://wg21.link/expr.type.conv#2">expr.type.conv</A>] paragraph 2 as follows:</P>

<BLOCKQUOTE>

...Otherwise, if the type is <I>cv</I> <TT>void</TT> and the initializer is
<TT>()</TT> <INS>or <TT>{}</TT></INS>, the expression is a prvalue of the
specified type that performs no initialization. Otherwise...

</BLOCKQUOTE>

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