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    CWG Issue 510</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="510"></A><H4>510.
  
Default initialization of POD classes?
</H4>
<B>Section: </B>11.9&#160; [<A href="https://wg21.link/class.init">class.init</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD1
 &#160;&#160;&#160;

 <B>Submitter: </B>Mike Miller
 &#160;&#160;&#160;

 <B>Date: </B>18 Mar 2005<BR>


<P>[Voted into WP at April, 2006 meeting.]</P>

<P>9.5 [<A href="https://wg21.link/dcl.init#10">dcl.init</A>] paragraph 10 makes it clear that
non-static POD class objects with no initializer are left uninitialized
and have an indeterminate initial value:</P>

<BLOCKQUOTE>

If no initializer is specified for an object, and the object is of
(possibly cv-qualified) non-POD class type (or array thereof), the
object shall be default-initialized; if the object is of
const-qualified type, the underlying class type shall have a
user-declared default constructor. Otherwise, if no initializer is
specified for a non-static object, the object and its subobjects, if
any, have an indeterminate initial value; if the object or any of
its subobjects are of const-qualified type, the program is ill-formed.

</BLOCKQUOTE>

<P>11.9 [<A href="https://wg21.link/class.init#1">class.init</A>] paragraph 1, however, implies that all
class objects without initializers, whether POD or not, are
default-initialized:</P>

<BLOCKQUOTE>

When no initializer is specified for an object of (possibly
cv-qualified) class type (or array thereof), or the initializer has
the form <TT>()</TT>, the object is initialized as specified in
9.5 [<A href="https://wg21.link/dcl.init">dcl.init</A>]. The object is default-initialized if there
is no initializer, or value-initialized if the initializer
is <TT>()</TT>.

</BLOCKQUOTE>

<P><B>Proposed resolution (October, 2005):</B></P>

<P>Remove the indicated words from 11.9 [<A href="https://wg21.link/class.init#1">class.init</A>] paragraph 1:</P>

<BLOCKQUOTE>

When no initializer is specified for an object of (possibly
cv-qualified) class type (or array thereof), or the initializer has
the form <TT>()</TT>, the object is initialized as specified in
9.5 [<A href="https://wg21.link/dcl.init">dcl.init</A>]. <DEL>The object is default-initialized if
there is no initializer, or value-initialized if the initializer
is <TT>()</TT>.</DEL>

</BLOCKQUOTE>

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