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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="1181"></A><H4>1181.
  
What is a &#8220;built-in type?&#8221;
</H4>
<B>Section: </B>6.9&#160; [<A href="https://wg21.link/basic.types">basic.types</A>]
 &#160;&#160;&#160;

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

 <B>Submitter: </B>Barry Hedquist
 &#160;&#160;&#160;

 <B>Date: </B>2010-08-26<BR>


<P>[Voted into the WP at the March, 2011 meeting.]</P>

<P>The current draft uses the term &#8220;built-in type&#8221; several
times, but it is not defined anywhere. The Index appears to make it
synonymous with &#8220;fundamental type,&#8221; but the implication of
7.3 [<A href="https://wg21.link/conv#1">conv</A>] paragraph 1 is that compound types like pointers
should also be considered as &#8220;built-in.&#8221;</P>

<P><B>Proposed resolution (January, 2011):</B></P>

<OL>
<LI><P>Change 6.8.2 [<A href="https://wg21.link/intro.object#7">intro.object</A>] paragraph 7 as follows:</P></LI>

<BLOCKQUOTE>

[<I>Note:</I> C++ provides a variety of <DEL>built-in</DEL>
<INS>fundamental</INS> types and several ways of composing new types
from existing types (6.9 [<A href="https://wg21.link/basic.types">basic.types</A>]). &#8212;<I>end
note</I>]

</BLOCKQUOTE>

<LI><P>Change 5.5 [<A href="https://wg21.link/lex.pptoken">lex.pptoken</A>] as follows:</P></LI>

<BLOCKQUOTE>

[<I>Example:</I> The program fragment <TT>x+++++y</TT> is parsed as
<TT>x ++ ++ + y</TT>, which, if <TT>x</TT> and <TT>y</TT> <DEL>are of
built-in</DEL> <INS>have integral</INS> types, violates a constraint
on increment operators, even though the parse <TT>x ++ + ++ y</TT>
might yield a correct expression.  &#8212;<I>end example</I>]

</BLOCKQUOTE>

<LI><P>Change 17.3.5.2 [<A href="https://wg21.link/numeric.limits.members#58">numeric.limits.members</A>] paragraph 58 as follows:</P></LI>

<BLOCKQUOTE>

True if the set of values representable by the type is
finite.<SUP>220</SUP> [<I>Note:</I> All <DEL>built-in</DEL>
<INS>fundamental</INS> types <INS>(6.9.2 [<A href="https://wg21.link/basic.fundamental">basic.fundamental</A>])</INS>
are bounded.  This member would be false for arbitrary precision
types. &#8212;<I>end note</I>]

</BLOCKQUOTE>

<LI><P>Change 24.3.1 [<A href="https://wg21.link/iterator.requirements.general#1">iterator.requirements.general</A>] paragraph 1 as follows:</P></LI>

<BLOCKQUOTE>

...All input iterators <TT>i</TT> support the expression <TT>*i</TT>,
resulting in a value of some <DEL>class, enumeration, or
built-in</DEL> <INS>object</INS> type <TT>T</TT>, called the <I>value
type</I> of the iterator...

</BLOCKQUOTE>

<LI><P>Change 24.3.5.3 [<A href="https://wg21.link/input.iterators#1">input.iterators</A>] paragraph 1 as follows:</P></LI>

<BLOCKQUOTE>

A class or a <DEL>built-in</DEL> <INS>pointer</INS> type <TT>X</TT>
satisfies the requirements of an input iterator for the value type
<TT>T</TT> if <TT>X</TT> satisfies the <TT>Iterator</TT> (24.3.5.2 [<A href="https://wg21.link/iterator.iterators">iterator.iterators</A>]) and <TT>EqualityComparable</TT> (Table 33)
requirements and the expressions in Table 107 are valid and have the
indicated semantics.

</BLOCKQUOTE>

<LI><P>Change 24.3.5.4 [<A href="https://wg21.link/output.iterators#1">output.iterators</A>] paragraph 1 as follows:</P></LI>

<BLOCKQUOTE>

A class or a <DEL>built-in</DEL> <INS>pointer</INS> type <TT>X</TT>
satisfies the requirements of an output iterator <DEL>if
<TT>X</TT></DEL> if <TT>X</TT> satisfies the <TT>Iterator</TT>
requirements (24.3.5.2 [<A href="https://wg21.link/iterator.iterators">iterator.iterators</A>]) and the expressions in
Table 108 are valid and have the indicated semantics.

</BLOCKQUOTE>

<LI><P>Change 24.3.5.5 [<A href="https://wg21.link/forward.iterators#1">forward.iterators</A>] paragraph 1 as follows:</P></LI>

<BLOCKQUOTE>

A class or a <DEL>built-in</DEL> <INS>pointer</INS> type <TT>X</TT>
satisfies the requirements of a forward iterator if...

</BLOCKQUOTE>

<LI><P>Change 24.3.5.6 [<A href="https://wg21.link/bidirectional.iterators#1">bidirectional.iterators</A>] paragraph 1 as follows:</P></LI>

<BLOCKQUOTE>

A class or a <DEL>built-in</DEL> <INS>pointer</INS> type <TT>X</TT>
satisfies the requirements of a bidirectional iterator if, in addition
to satisfying the requirements for forward iterators, the following
expressions are valid as shown in Table 110.

</BLOCKQUOTE>

<LI><P>Change 24.3.5.7 [<A href="https://wg21.link/random.access.iterators#1">random.access.iterators</A>] paragraph 1 as follows:</P></LI>

<BLOCKQUOTE>

A class or a <DEL>built-in</DEL> <INS>pointer</INS> type <TT>X</TT>
satisfies the requirements of a random access iterator if, in addition
to satisfying the requirements for bidirectional iterators, the
following expressions are valid as shown in Table 111.

</BLOCKQUOTE>

<LI><P>Change C.7.3 [<A href="https://wg21.link/diff.basic">diff.basic</A>] section 3.1 as follows:</P></LI>

<BLOCKQUOTE>

<B>Rationale</B>: This avoids having different initialization rules
for <DEL>built-in</DEL> <INS>fundamental</INS> types and user-defined
types.

</BLOCKQUOTE>

<LI><P>Change C.7.7 [<A href="https://wg21.link/diff.class">diff.class</A>] section 9.1 as follows:</P></LI>

<BLOCKQUOTE>

...This new name space definition provides important notational
conveniences to C++ programmers and helps making the use of the
user-defined types as similar as possible to the use of
<DEL>built-in</DEL> <INS>fundamental</INS> types...

</BLOCKQUOTE>

<LI>
<P>Delete the index entry, &#8220;built-in type; see fundamental
type</P>.&#8221;</LI>

</OL>

<P>(Note: This resolution assumes that the resolution for
<A HREF="572.html">issue 572</A> has been applied, removing
&#8220;built-in type&#8221; from 7.3 [<A href="https://wg21.link/conv#1">conv</A>] paragraph 1.)</P>

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