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    CWG Issue 1063</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="1063"></A><H4>1063.
  
<TT>[[hiding]]</TT> with non-attribute declarations
</H4>
<B>Section: </B>_N3225_.7.6.5&#160; [<A href="https://wg21.link/dcl.attr.override">dcl.attr.override</A>]
 &#160;&#160;&#160;

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

 <B>Submitter: </B>Daveed Vandevoorde
 &#160;&#160;&#160;

 <B>Date: </B>2010-03-23<BR>


<P>[Voted into the WP at the March, 2011 meeting as part of paper N3272.]</P>



<P>There are some kinds of declarations that can appear in a derived
class and hide names from a base class, but for which the syntax does
not permit a <TT>[[hiding]]</TT> attribute.  For example:</P>

<PRE>
    struct B1 {
        int N;
        int M;
    };
    struct B2 {
        int M;
    };
    struct [[base_check]] D: B1, B2 {
        enum { N };    // hides B1::N but cannot take an attribute
        using B1::M;   // hides B2::M but cannot take an attribute
    };
</PRE>

<P><B>Additional note (October, 2010):</B></P>

<P>
<I>alias-declaration</I>s should also be considered in this
regard. </P>

<P><B>Notes from the November, 2010 meeting:</B></P>

<P>Paper N3206 did not address these cases; in fact, it introduced
additional member declarations that cannot be annotated as hiding a
base class member (<I>function-definition</I>s and
<I>template-declaration</I>s), because the <TT>new</TT>
<I>virt-specifier</I> applies to a <I>member-declarator</I> and none
of these <I>member-declaration</I>s uses a <I>member-declarator</I>.</P>

<P><B>Additional note (November, 2010):</B></P>

<P>The injected-class-name can also hide a name from a base class
but cannot be annotated with <TT>new</TT>.</P>

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