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    CWG Issue 2689</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="2689"></A><H4>2689.
  
Are cv-qualified <TT>std::nullptr_t</TT> fundamental types?
</H4>
<B>Section: </B>6.9.2&#160; [<A href="https://wg21.link/basic.fundamental">basic.fundamental</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD7
 &#160;&#160;&#160;

 <B>Submitter: </B>Anoop Rana
 &#160;&#160;&#160;

 <B>Date: </B>2022-12-08<BR>


<P>[Accepted as a DR at the March, 2024 meeting.]</P>

<P>It is unclear whether <I>cv</I> <TT>std::nullptr_t</TT> is a
fundamental type, given that it is declared in a library header and
cv-qualifications are not mentioned in
6.9.2 [<A href="https://wg21.link/basic.fundamental#15">basic.fundamental</A>] paragraph 15.</P>

<P><B>Proposed resolution (approved by CWG 2023-12-01):</B></P>

<P>Change in 6.9.2 [<A href="https://wg21.link/basic.fundamental#15">basic.fundamental</A>] paragraph 15 as follows:</P>

<BLOCKQUOTE>

<INS>The types denoted by <I>cv</I> <TT>std::nullptr_t</TT> are
distinct types.</INS> A value of type <TT>std::nullptr_t</TT> is a
null pointer constant (7.3.12 [<A href="https://wg21.link/conv.ptr">conv.ptr</A>]). Such values
participate in the pointer and the pointer-to-member conversions
(7.3.12 [<A href="https://wg21.link/conv.ptr">conv.ptr</A>],
7.3.13 [<A href="https://wg21.link/conv.mem">conv.mem</A>]).  <TT>sizeof(std::nullptr_t)</TT> shall
be equal to <TT>sizeof(void*)</TT>.

<P>The types described in this subclause are called <I>fundamental
types</I>.  [<I>Note 11:</I> Even if the implementation defines two or
more fundamental types to have the same value representation, they are
nevertheless different types. &#8212;<I>end note</I>]</P>

</BLOCKQUOTE>


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