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    CWG Issue 516</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="516"></A><H4>516.
  
Use of <TT>signed</TT> in bit-field declarations
</H4>
<B>Section: </B>9.2.9.3&#160; [<A href="https://wg21.link/dcl.type.simple">dcl.type.simple</A>]
 &#160;&#160;&#160;

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

 <B>Submitter: </B>comp.std.c++
 &#160;&#160;&#160;

 <B>Date: </B>25 Apr 2005<BR>


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

<P>9.2.9.3 [<A href="https://wg21.link/dcl.type.simple#3">dcl.type.simple</A>] paragraph 3 reads,</P>

<BLOCKQUOTE>

It is implementation-defined whether bit-fields and objects
of <TT>char</TT> type are represented as signed or unsigned
quantities.  The <TT>signed</TT> specifier forces <TT>char</TT>
objects and bit-fields to be signed; it is redundant with other
integral types.

</BLOCKQUOTE>

<P>The last sentence in that quote is misleading w.r.t. bit-fields. The
first sentence in that quote is correct but incomplete.</P>

<P>Proposed fix: change the two sentences to read:</P>

<BLOCKQUOTE>

It is implementation-defined whether objects of <TT>char</TT> type are
represented as signed or unsigned quantities. The <TT>signed</TT>
specifier forces <TT>char</TT> objects signed; it is redundant with
other integral types except when declaring bit-fields (11.4.10 [<A href="https://wg21.link/class.bit">class.bit</A>]).

</BLOCKQUOTE>

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

<P>Change 9.2.9.3 [<A href="https://wg21.link/dcl.type.simple#3">dcl.type.simple</A>] paragraph 3 as indicated:</P>

<BLOCKQUOTE>

When multiple <I>simple-type-specifier</I>s are allowed, they can be
freely intermixed with other <I>decl-specifier</I>s in any
order. <INS>[<I>Note:</I></INS> It is implementation-defined whether
<DEL>bit-fields and</DEL> objects of <TT>char</TT> type <INS>and certain
bit-fields (11.4.10 [<A href="https://wg21.link/class.bit">class.bit</A>])</INS> are represented as signed
or unsigned quantities.  The <TT>signed</TT> specifier
forces <INS>bit-fields and</INS> <TT>char</TT> objects <DEL>and
bit-fields</DEL> to be signed; it is redundant <DEL>with other integral
types</DEL> <INS>in other contexts</INS>. <INS>&#8212;<I>end note</I>]</INS>

</BLOCKQUOTE>

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