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    CWG Issue 1070</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="1070"></A><H4>1070.
  
Missing initializer clauses in aggregate initialization
</H4>
<B>Section: </B>9.5.2&#160; [<A href="https://wg21.link/dcl.init.aggr">dcl.init.aggr</A>]
 &#160;&#160;&#160;

 <B>Status: </B>C++11
 &#160;&#160;&#160;

 <B>Submitter: </B>Jason Merrill
 &#160;&#160;&#160;

 <B>Date: </B>2010-06-01<BR>


<P>[Voted into the WP at the November, 2010 meeting.]</P>



<A HREF="990.html">Issue 990</A> added the following text to
9.5.5 [<A href="https://wg21.link/dcl.init.list#3">dcl.init.list</A>] paragraph 3:

<UL><LI><P>Otherwise, if the initializer list has no elements and
<TT>T</TT> is an aggregate, each of the members of <TT>T</TT> is
initialized from an empty initializer
list. [<I>Example:</I>...</P></LI></UL>

<P>A better way to handle this would be to delete that bullet and
change 9.5.2 [<A href="https://wg21.link/dcl.init.aggr#7">dcl.init.aggr</A>] paragraph 7 as follows:</P>

<BLOCKQUOTE>

If there are fewer <I>initializer-clause</I>s in the list than there
are members in the aggregate, then each member not explicitly
initialized shall be <DEL>value-initialized (9.5 [<A href="https://wg21.link/dcl.init">dcl.init</A>])</DEL> <INS>initialized from an empty initializer list
(9.5.5 [<A href="https://wg21.link/dcl.init.list">dcl.init.list</A>])</INS>.

</BLOCKQUOTE>

<P>This makes <TT>{ }</TT> less of a special case and makes the
following example work:</P>

<PRE>
    struct A {
       A(std::initializer_list&lt;int&gt;);
    };
    struct B {
       int i;
       A a;
    };
    B b = { 1 };
</PRE>

<P><B>Proposed resolution (August, 2010):</B></P>

<OL>
<LI><P>Delete 9.5.5 [<A href="https://wg21.link/dcl.init.list#3.2">dcl.init.list</A>] bullet 3.2,
includeing the example:</P></LI>

<UL><LI><DEL>Otherwise, if the initializer list has no
elements and <TT>T</TT> is an aggregate, each of the members
of <TT>T</TT> is initialized from an empty initializer
list. [<I>Example:</I>...</DEL></LI></UL>

<LI><P>Change 9.5.2 [<A href="https://wg21.link/dcl.init.aggr#7">dcl.init.aggr</A>] paragraph 7 as follows:</P></LI>

<BLOCKQUOTE>

If there are fewer <I>initializer-clause</I>s in the list than there
are members in the aggregate, then each member not explicitly
initialized shall be <DEL>value-initialized (9.5 [<A href="https://wg21.link/dcl.init">dcl.init</A>])</DEL> <INS>initialized from an empty initializer list
(9.5.5 [<A href="https://wg21.link/dcl.init.list">dcl.init.list</A>])</INS>.

</BLOCKQUOTE>

</OL>

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