<section xmlns="http://docbook.org/ns/docbook" version="5.0"
   xml:id="status.iso.2020" xreflabel="Status C++ 2020">
<?dbhtml filename="status_iso_cxx2020.html"?>

<info><title>C++ 2020</title>
  <keywordset>
    <keyword>ISO C++</keyword>
    <keyword>2020</keyword>
  </keywordset>
</info>

<para>
In this implementation the <literal>-std=gnu++20</literal> or
<literal>-std=c++20</literal> flag must be used to enable language
and library
features. See <link linkend="manual.intro.using.flags">dialect</link>
options. The pre-defined symbol
<constant>__cplusplus</constant> is used to check for the
presence of the required flag.
</para>

<para>
This section describes the C++20 and library TS support in
the GCC 15 release series.
</para>

<para>
The following table lists new library features that are included in
the C++20 standard. The "Proposal" column provides a link to the
ISO C++ committee proposal that describes the feature, while the "Status"
column indicates the first version of GCC that contains an implementation of
this feature (if it has been implemented).
A dash (&#x2014;) in the status column indicates that the changes in the proposal
either do not affect the code in libstdc++, or the changes are not required for conformance.
The "SD-6 Feature Test / Notes" column shows the corresponding macro or header from
<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations">SD-6:
Feature-testing recommendations for C++</link> (where applicable)
or any notes about the implementation.
</para>

<table frame="all" xml:id="table.cxx20_features">
<title>C++ 2020 Library Features</title>

<tgroup cols="4" align="left" colsep="0" rowsep="1">
<colspec colname="c1"/>
<colspec colname="c2"/>
<colspec colname="c3"/>
<colspec colname="c4"/>
  <thead>
    <row>
      <entry>Library Feature</entry>
      <entry>Proposal</entry>
      <entry>Status</entry>
      <entry>SD-6 Feature Test / Notes</entry>
    </row>
  </thead>

  <tbody>

    <row>
      <entry namest="c1" nameend="c4" align="left">
        <emphasis role="bold">Compile-time programming</emphasis>
      </entry>
    </row>

    <row>
      <entry>  Add constexpr modifiers to functions in <code>&lt;algorithm&gt;</code> and <code>&lt;utility&gt;</code> Headers </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0202r3.html">
        P0202R3 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_constexpr_algorithms &gt;= 201703L</code> </entry>
    </row>

    <row>
      <entry>  Constexpr for <code>swap</code> and swap related functions </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0879r0.html">
        P0879R0 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_constexpr_algorithms &gt;= 201806L</code> </entry>
    </row>

    <row>
      <entry>  Constexpr for <code>std::complex</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0415r1.html">
        P0415R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_constexpr_complex &gt;= 201711L</code> (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry>  <code>std::is_constant_evaluated()</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0595r2.html">
        P0595R2 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_is_constant_evaluated &gt;= 201811L</code> </entry>
    </row>

    <row>
      <entry>  More constexpr containers </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0784r7.html">
        P0784R7 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_constexpr_dynamic_alloc &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry>  Making <code>std::string</code> constexpr </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0980r1.pdf">
        P0980R1 </link>
      </entry>
      <entry align="center"> 12.1 </entry>
      <entry> <code>__cpp_lib_constexpr_string &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry>  Making <code>std::vector</code> constexpr </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1004r2.pdf">
        P1004R2 </link>
      </entry>
      <entry align="center"> 12.1 </entry>
      <entry> <code>__cpp_lib_constexpr_vector &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry>  Constexpr in <code>std::pointer_traits</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1006r1.pdf">
        P1006R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_constexpr_memory &gt;= 201811L</code> (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry>  constexpr for <code>&lt;numeric&gt;</code> algorithms </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1645r1.html">
        P1645R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_constexpr_numeric &gt;= 201911L</code> </entry>
    </row>

    <row>
      <entry>  Constexpr iterator requirements </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0858r0.html">
        P0858R0 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry>
        <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
        <row><entry> <code>__cpp_lib_array_constexpr &gt;= 201803L</code> </entry></row>
        <row><entry> <code>__cpp_lib_string_view &gt;= 201803L</code> </entry></row>
        <row><entry> (both since 9.4, see Note 1) </entry></row>
        </tbody></tgroup></informaltable>
      </entry>
    </row>

    <row>
      <entry>  <code>constexpr</code> comparison operators for <code>std::array</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1023r0.pdf">
        P1023R0 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_array_constexpr &gt;= 201806</code> </entry>
    </row>

    <row>
      <entry>  Misc constexpr bits </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1032r1.html">
        P1032R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry>
        <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
        <row><entry> <code>__cpp_lib_array_constexpr &gt;= 201811L</code> </entry></row>
        <row><entry> <code>__cpp_lib_constexpr_functional &gt;= 201811L</code> </entry></row>
        <row><entry> <code>__cpp_lib_constexpr_iterator &gt;= 201811L</code> </entry></row>
        <row><entry> <code>__cpp_lib_constexpr_string_view &gt;= 201811L</code> </entry></row>
        <row><entry> <code>__cpp_lib_constexpr_tuple &gt;= 201811L</code> </entry></row>
        <row><entry> <code>__cpp_lib_constexpr_utility &gt;= 201811L</code> </entry></row>
        </tbody></tgroup></informaltable>
      </entry>
    </row>

    <row>
      <entry>  <code>constexpr <emphasis>INVOKE</emphasis></code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1065r2.html">
        P1065R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_constexpr_functional &gt;= 201907L</code> </entry>
    </row>


    <row>
      <entry>  Transformation Trait <code>remove_cvref</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0550r2.pdf">
        P0550R2 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_remove_cvref &gt;= 201711L</code> (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry>  Implicit conversion traits and utility functions </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0758r1.html">
        P0758R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_is_nothrow_convertible &gt;= 201806L</code>  (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry>  The <code>identity</code> metafunction </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0887r1.pdf">
        P0887R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_type_identity &gt;= 201806L</code> (since 9.4, see Note 1) </entry>
    </row>


    <row>
      <entry>  <code>unwrap_ref_decay</code> and <code>unwrap_reference</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0318r1.pdf">
        P0318R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_unwrap_ref &gt;= 201811L</code> (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry>  Improving Completeness Requirements for Type Traits </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1285r0.pdf">
        P1285R0 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry> Most misuses are diagnosed, but not all. </entry>
    </row>

    <row>
      <entry>  Missing feature test macros </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1353r0.html">
        P1353R0 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <entry> Making std::underlying_type SFINAE-friendly </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0340r3.html">
        P0340R3 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <entry> Traits for [Un]bounded Arrays </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1357r1.pdf">
        P1357R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_bounded_array_traits &gt;= 201902L</code> </entry>
    </row>

    <row>
      <entry> Layout-compatibility and pointer-interconvertibility traits </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0466r5.pdf">
        P0466R5 </link>
      </entry>
      <entry align="center"> 12.1 </entry>
      <entry>
        <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
        <row><entry> <code>__cpp_lib_is_layout_compatible &gt;= 201907L</code> </entry></row>
        <row><entry> <code>__cpp_lib_is_pointer_interconvertible &gt;= 201907L</code> </entry></row>
        </tbody></tgroup></informaltable>
      </entry>
    </row>

    <row>
      <entry>  Integrating feature-test macros into the C++ WD </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0941r2.html">
        P0941R2 </link>
      </entry>
      <entry align="center"> 5.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  <code>&lt;version&gt;</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0754r2.pdf">
        P0754R2 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__has_include(&lt;version&gt;)</code> </entry>
    </row>


    <row>
      <entry namest="c1" nameend="c4" align="left">
        <emphasis role="bold">Synchronization</emphasis>
      </entry>
    </row>

    <row>
      <entry>  Atomic Ref </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0019r8.html">
        P0019R8 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_atomic_ref &gt;= 201806L</code> </entry>
    </row>

    <row>
      <entry>  Floating Point Atomic </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0020r6.html">
        P0020R6 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_atomic_float &gt;= 201711L</code> </entry>
    </row>

    <row>
      <entry>  C++ Synchronized Buffered Ostream </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0053r7.pdf">
        P0053R7 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry> <code>__cpp_lib_syncbuf &gt;= 201711L</code> </entry>
    </row>

    <row>
      <entry>  Manipulators for C++ Synchronized Buffered Ostream </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0753r2.pdf">
        P0753R2 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry> <code>__cpp_lib_syncbuf &gt;= 201803L</code> </entry>
    </row>

    <row>
      <entry>  Make <code>std::memory_order</code> a scoped enumeration </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0439r0.html">
        P0439R0 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  The Curious Case of Padding Bits, Featuring Atomic Compare-and-Exchange </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0528r3.html">
        P0528R3 </link>
      </entry>
      <entry align="center"> 13.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  Atomic <code>shared_ptr</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0718r2.html">
        P0718R2 </link>
      </entry>
      <entry align="center"> 12.1 </entry>
      <entry> <code> __cpp_lib_atomic_shared_ptr &gt;= 201711L</code> </entry>
    </row>

    <row>
      <entry> std::stop_token and std::jthread </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0660r10.pdf">
        P0660R10 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_jthread &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry> Rename <code>condition_variable_any</code> interruptible wait methods </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1869r1.html">
        P1869R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_jthread &gt;= 201911L</code> </entry>
    </row>

    <row>
      <entry> Atomic waiting and notifying, std::semaphore, std::latch and std::barrier </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1135r6.html">
        P1135R6 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry>
        <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
        <row><entry> <code>__cpp_lib_atomic_lock_free_type_aliases &gt;= 201907L</code> </entry></row>
        <row><entry> <code>__cpp_lib_atomic_flag_test &gt;= 201907L</code> </entry></row>
        <row><entry> <code>__cpp_lib_atomic_wait &gt;= 201907L</code> </entry></row>
        <row><entry> <code>__cpp_lib_semaphore &gt;= 201907L</code> </entry></row>
        <row><entry> <code>__cpp_lib_latch &gt;= 201907L</code> </entry></row>
        <row><entry> <code>__cpp_lib_barrier &gt;= 201907L</code> </entry></row>
        </tbody></tgroup></informaltable>
      </entry>
    </row>

    <row>
      <entry> Fixing Atomic Initialization </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0883r2.pdf">
        P0883R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_atomic_value_initialization &gt;= 201911L</code> </entry>
    </row>


    <row>
      <entry namest="c1" nameend="c4" align="left">
        <emphasis role="bold">Ranges and Concepts</emphasis>
      </entry>
    </row>

    <row>
      <entry>  Standard Library Concepts </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0898r3.pdf">
        P0898R3 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_concepts &gt;= 201806L</code> </entry>
    </row>

    <row>
      <entry>  Rename concepts to standard_case for C++20, while we still can </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1754r1.pdf">
        P1754R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_concepts &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry>  Wording for <emphasis><code>boolean-testable</code></emphasis> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1964r2.html">
        P1964R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_concepts &gt;= 202002L</code> </entry>
    </row>

    <row>
      <entry>  The One Ranges Proposal </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0896r4.pdf">
        P0896R4 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_ranges &gt;= 201811L</code> </entry>
    </row>

    <row>
      <entry>  Input Range Adaptors </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1035r7.pdf">
        P1035R7 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_ranges &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry>  <code>ranges</code> compare algorithm are over-constrained </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1716r3.html">
        P1716R3 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_ranges &gt;= 201911L</code> </entry>
    </row>

    <row>
      <entry>  Remove CommonReference requirement from StrictWeakOrdering (a.k.a Fixing Relations) </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1248r1.html">
        P1248R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry />
    </row>

    <row>
      <entry> Ranges Design Cleanup </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1252r2.pdf">
        P1252R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry />
    </row>

    <row>
      <entry> Avoid template bloat for <code>safe_ranges</code> in combination with ‘subrange-y’ view adaptors.</entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1739r4.html">
        P1739R4 </link>
      </entry>
      <entry align="center"> 12.1 </entry>
      <entry />
    </row>


    <row>
      <entry namest="c1" nameend="c4" align="left">
        <emphasis role="bold">Time, dates, calendars, time zones</emphasis>
      </entry>
    </row>

    <row>
      <entry>  Extending chrono to Calendars and Time Zones </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0355r7.html">
        P0355R7 </link>
      </entry>
      <entry> 14.1 (see Note 2) </entry>
      <entry> <code>__cpp_lib_chrono &gt;= 201803L</code> </entry>
    </row>

    <row>
      <entry> Miscellaneous minor fixes for chrono </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1466r3.html">
        P1466R3 </link>
      </entry>
      <entry> 11.1 (see Note 2) </entry>
      <entry> <code>__cpp_lib_chrono &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry>  <code>&lt;chrono&gt;</code> <code>zero()</code>, <code>min()</code>, and <code>max()</code> should be <code>noexcept</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0972r0.pdf">
        P0972R0 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>


    <row>
      <entry namest="c1" nameend="c4" align="left">
        <emphasis role="bold">Three-way comparison</emphasis>
      </entry>
    </row>

    <row>
      <entry>  Library Support for the Spaceship (Comparison) Operator </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0768r1.pdf">
        P0768R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_three_way_comparison &gt;= 201711L</code> </entry>
    </row>

    <row>
      <entry>  Symmetry for spaceship </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0905r1.html">
        P0905R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry />
    </row>

    <row>
      <entry> Adding &lt;=&gt; to the standard library </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1614r2.html">
        P1614R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry>
        <code>__cpp_lib_three_way_comparison &gt;= 201907L</code>
      </entry>
    </row>


    <row>
      <entry namest="c1" nameend="c4" align="left">
        <emphasis role="bold">Strings and text</emphasis>
      </entry>
    </row>

    <row>
      <entry>  <code>string::reserve</code> Should Not Shrink </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0966r1.html">
        P0966R1 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  <code>char8_t</code>: A type for UTF-8 characters and strings </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0482r6.html">
        P0482R6 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_char8_t &gt;= 201811L</code> </entry>
    </row>

    <row>
      <entry>  <code>char8_t</code> backward compatibility remediation </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1423r3.html">
        P1423R3 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_char8_t &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry> Text formatting </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0645r10.html">
        P0645R10 </link>
      </entry>
      <entry align="center"> 13.1 </entry>
      <entry>
        <code>__cpp_lib_format &gt;= 201907L</code>
      </entry>
    </row>

    <row>
      <entry> Integration of chrono with text formatting </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1361r2.pdf">
        P1361R2 </link>
      </entry>
      <entry align="center"> 13.1 </entry>
      <entry>
        <code>__cpp_lib_format &gt;= 201907L</code>
      </entry>
    </row>

    <row>
      <entry> Printf corner cases in <code>std::format</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1652r1.html">
        P1652R1 </link>
      </entry>
      <entry align="center"> 13.1 </entry>
      <entry>
        <code>__cpp_lib_format &gt;= 201907L</code>
      </entry>
    </row>

    <row>
      <entry>  String Prefix and Suffix Checking </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0457r2.html">
        P0457R2 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_starts_ends_with &gt;= 201711L</code> (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry>  Update The Reference To The Unicode Standard </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1025r1.html">
        P1025R1 </link>
      </entry>
      <entry align="center"> &#x2014;</entry>
      <entry />
    </row>


    <row>
      <entry namest="c1" nameend="c4" align="left">
        <emphasis role="bold">Containers</emphasis>
      </entry>
    </row>

    <row>
      <entry> span: bounds-safe views for sequences of objects </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0122r7.pdf">
        P0122R7 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_span &gt;= 201803L</code> </entry>
    </row>

    <row>
      <entry>
        Usability Enhancements for <classname>std::span</classname>
      </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1024r3.pdf">
        P1024R3 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_span &gt;= 201902L</code> </entry>
    </row>

    <row>
      <entry>  Should Span be Regular? </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1085r2.md">
        P1085R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry/>
    </row>

    <row>
      <entry> Fixed-size <code>&lt;span&gt;</code> construction from dynamic range </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1976r2.html">
        P1976R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_span &gt;= 202002L</code> </entry>
    </row>

    <row>
      <entry> <code>std::to_array</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0325r4.html">
        P0325R4 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_to_array &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry>  Checking for Existence of an Element in Associative Containers </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0458r2.html">
        P0458R2 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  Comparing Unordered Containers </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0809r0.pdf">
        P0809R0 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry />
    </row>

    <row>
      <entry>  Heterogeneous lookup for unordered containers </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0919r3.html">
        P0919R3 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry> <code>__cpp_lib_generic_unordered_lookup &gt;= 201811</code> </entry>
    </row>

    <row>
      <entry> Refinement Proposal for P0919 </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1690r1.html">
        P1690R1 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry/>
    </row>

    <row>
      <entry>  Adopt Consistent Container Erasure from Library Fundamentals 2 for C++20 </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1209r0.html">
        P1209R0 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_erase_if &gt;= 201811L</code> </entry>
    </row>

    <row>
      <entry>  Improving the Return Value of Erase-Like Algorithms </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0646r1.pdf">
        P0646R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_list_remove_return_type &gt;= 201806L</code> </entry>
    </row>

    <row>
      <entry>  Improving the Return Value of Erase-Like Algorithms II: Free <code>erase</code>/<code>erase_if</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1115r3.pdf">
        P1115R3 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry>
        <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
        <row><entry> <code>__cpp_lib_erase_if &gt;= 202002L</code> </entry></row>
        <row><entry> (defined to <code>201900L</code> for GCC 9.1 and 9.2 so use <code>&gt; 201811L</code>) </entry></row>
        </tbody></tgroup></informaltable>
      </entry>
    </row>

    <row>
      <entry> Signed ssize() functions, unsigned size() functions </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1227r2.html">
        P1227R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_ssize &gt;= 201902L</code> </entry>
    </row>


    <row>
      <entry namest="c1" nameend="c4" align="left">
        <emphasis role="bold">Memory management</emphasis>
      </entry>
    </row>

    <row>
      <entry>  Utility to convert a pointer to a raw pointer </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0653r2.html">
        P0653R2 </link>
      </entry>
      <entry align="center"> 8.1 </entry>
      <entry> <code>__cpp_lib_to_address &gt;= 201711L</code> (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry>  Extending <code>make_shared</code> to Support Arrays </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0674r1.html">
        P0674R1 </link>
      </entry>
      <entry align="center"> 12.1 </entry>
      <entry> <code>__cpp_lib_shared_ptr_arrays &gt;= 201707L</code> </entry>
    </row>

    <row>
      <entry>  Efficient sized delete for variable sized classes </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0722r3.html">
        P0722R3 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_destroying_delete &gt;= 201806L</code> </entry>
    </row>

    <row>
      <entry>  Utility functions to implement uses-allocator construction </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0591r4.pdf">
        P0591R4 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry>
        <code>std::scoped_allocator_adaptor</code> changes missing in 9.1.0
      </entry>
    </row>

    <row>
      <entry>  <code>std::assume_aligned</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1007r3.pdf">
        P1007R3 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_assume_aligned &gt;= 201811L</code> (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry>  Smart pointer creation with default initialization </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1020r1.html">
        P1020R1 </link>
      </entry>
      <entry align="center"> 12.1 </entry>
      <entry> <code>__cpp_lib_smart_ptr_for_overwrite &gt;= 201811L</code> </entry>
    </row>

    <row>
      <entry>  Rename "default_init" Functions </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1973r1.pdf">
        P1973R1 </link>
      </entry>
      <entry align="center"> 12.1 </entry>
      <entry> <code>__cpp_lib_smart_ptr_for_overwrite &gt;= 201811L</code> </entry>
    </row>

    <row>
      <entry>  Make stateful allocator propagation more consistent for <code>operator+(basic_string)</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1165r1.html">
        P1165R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry />
    </row>

    <row>
      <entry>
        <classname>polymorphic_allocator&lt;&gt;</classname> as a vocabulary type
      </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0339r6.pdf">
        P0339R6 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry>
      <code>__cpp_lib_polymorphic_allocator &gt;= 201902L</code> (since 9.4, see Note 1)
      </entry>
    </row>

    <row>
      <entry>  LWG 2511: guaranteed copy elision for piecewise construction </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0475r1.html">
        P0475R1 </link>
      </entry>
      <entry align="center"> 7.1 </entry>
      <entry />
    </row>


    <row>
      <entry namest="c1" nameend="c4" align="left">
        <emphasis role="bold">Miscellaneous</emphasis>
      </entry>
    </row>

    <row>
      <entry>  <code>nodiscard</code> in the Library </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0600r1.pdf">
        P0600R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  de-pessimize legacy algorithms with <code>std::move</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0616r0.pdf">
        P0616R0 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  Deprecate POD </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0767r1.html">
        P0767R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  Treating Unnecessary <code>decay</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0777r1.pdf">
        P0777R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <?dbhtml bgcolor="#C8B0B0" ?>
      <entry>  Thou Shalt Not Specialize std Function Templates! </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0551r3.pdf">
        P0551R3 </link>
      </entry>
      <entry align="center"> </entry>
      <entry>These changes will not be implemented.</entry>
    </row>

    <row>
      <entry>  Bit-casting object representations </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0476r2.html">
        P0476R2 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry> <code>__cpp_lib_bit_cast &gt;= 201806L</code> </entry>
    </row>

    <row>
      <entry>  Integral power-of-2 operations </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0556r3.html">
        P0556R3 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_int_pow2 &gt;= 201806L</code> (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry> On the names of low-level bit manipulation functions </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1956r1.pdf">
        P1956R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_int_pow2 &gt;= 202002L</code> </entry>
    </row>

    <row>
      <entry> Safe integral comparisons </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p0586r2.html">
        P0586R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_integer_comparison_functions &gt;= 202002L</code> </entry>
    </row>

    <row>
      <entry>  Reviewing Deprecated Facilities of C++17 for C++20 </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0619r4.html">
        P0619R4 </link>
      </entry>
      <entry align="center"> 12.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  <code>fpos</code> Requirements </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0759r1.html">
        P0759R1 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry />
    </row>

    <row>
      <entry>  Add <code>shift</code> to <code>&lt;algorithm&gt;</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0769r2.pdf">
        P0769R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_shift &gt;= 201806L</code> </entry>
    </row>

    <row>
      <entry>  Standard Library Specification in a Concepts and Contracts World </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0788r3.pdf">
        P0788R3 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry />
    </row>

    <row>
      <entry>  <code>explicit(bool)</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0892r2.html">
        P0892R2 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry />
    </row>

    <row>
      <entry>  Eradicating unnecessarily explicit default constructors from the standard library </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0935r0.html">
        P0935R0 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  <code>std::function</code> move constructor should be <code>noexcept</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0771r1.pdf">
        P0771R1 </link>
      </entry>
      <entry align="center"> 7.2 </entry>
      <entry />
    </row>

    <row>
      <entry>  Simplified partial function application </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0356r5.html">
        P0356R5 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_bind_front &gt;= 201811L</code> </entry>
    </row>

    <row>
      <entry>  <code>bind_front</code> should not unwrap <code>reference_wrapper</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1651r0.html">
        P1651R0 </link>
      </entry>
      <entry align="center"> 9.3 </entry>
      <entry> <code>__cpp_lib_bind_front &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry>  <code>reference_wrapper</code> for incomplete types </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0357r3.html">
        P0357R3 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  Fixing <code>operator&gt;&gt;(basic_istream&amp;, CharT*)</code> (LWG 2499) </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0487r1.html">
        P0487R1 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  <code>variant</code> and <code>optional</code> should propagate copy/move triviality </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0602r4.html">
        P0602R4 </link>
      </entry>
      <entry align="center"> 8.3 </entry>
      <entry />
    </row>

    <row>
      <entry>  A sane <code>variant</code> converting constructor </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0608r3.html">
        P0608R3 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  <code>visit&lt;R&gt;</code>: Explicit Return Type for <code>visit</code> </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0655r1.pdf">
        P0655R1 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  P0899R1 - LWG 3016 is not a defect </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0899r1.html">
        P0899R1 </link>
      </entry>
      <entry align="center"> 7.1 </entry>
      <entry />
    </row>

    <row>
      <entry>  Editorial Guidance for merging P0019r8 and P0528r3 </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1123r0.html">
        P1123R0 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry />
    </row>

    <row>
      <entry>  Cleaning up Clause 20 </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1148r0.pdf">
        P1148R0 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry />
    </row>

    <row>
      <?dbhtml bgcolor="#C8B0B0" ?>
      <entry>  Completing the Rebase of Library Fundamentals, Version 3, Working Draft </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1210r0.html">
        P1210R0 </link>
      </entry>
      <entry align="center"> </entry>
      <entry />
    </row>

    <row>
      <entry>  Alternative Wording for P0907R4 Signed Integers are Two's Complement </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html">
        P1236R1 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry/>
    </row>

    <row>
      <entry>
        I Stream, You Stream, We All Stream for
        <classname>istream_iterator</classname>
      </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0738r2.html">
        P0738R2 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry />
    </row>

    <row>
      <entry>
        Mandating the Standard Library:
        Clause 16 - Language support library
      </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1458r1.pdf">
        P1458R1 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry/>
    </row>

    <row>
      <entry>
        Mandating the Standard Library:
        Clause 18 - Diagnostics library
      </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1458r1.pdf">
        P1459R1 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry/>
    </row>

    <row>
      <entry>
        Mandating the Standard Library:
        Clause 20 - Strings library
      </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1462r1.html">
        P1462R1 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry/>
    </row>

    <row>
      <entry>
        Mandating the Standard Library:
        Clause 21 - Containers library
      </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1463r1.pdf">
        P1463R1 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry/>
    </row>

    <row>
      <entry>
        Mandating the Standard Library:
        Clause 22 - Iterators library
      </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1464r1.pdf">
        P1464R1 </link>
      </entry>
      <entry align="center"> &#x2014; </entry>
      <entry />
    </row>

    <row>
      <entry> Make <code>create_directory()</code> Intuitive </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1164r1.pdf">
        P1164R1
  </link>
      </entry>
      <entry align="center"> 8.3 </entry>
      <entry> Treated as a DR for C++17 </entry>
    </row>

    <row>
      <entry>
        Target Vectorization Policies from Parallelism V2 TS to C++20
      </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1001r2.html">
        P1001R2 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_execution &gt;= 201902L</code> (since 9.4, see Note 1)</entry>
    </row>

    <row>
      <entry> Merge Coroutines TS into C++20 working draft </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0912r5.html">
        P0912R5 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_coroutines &gt;= 201902L</code> </entry>
    </row>

    <row>
      <entry>  Endian just Endian </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0463r1.html">
        P0463R1 </link>
      </entry>
      <entry align="center"> 8.1 </entry>
      <entry> <code>__cpp_lib_endian &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry> Bit operations </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0553r4.html">
        P0553R4 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_bitops &gt;= 201907L</code> (since 9.4, see Note 1) </entry>
    </row>

    <row>
      <entry>  Well-behaved interpolation for numbers and pointers </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0811r3.html">
        P0811R3 </link>
      </entry>
      <entry align="center"> 9.1 </entry>
      <entry> <code>__cpp_lib_interpolate &gt;= 201902L</code> </entry>
    </row>

    <row>
      <entry> Mathematical constants </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0631r8.pdf">
        P0631R8 </link>
      </entry>
      <entry align="center"> 10.1 </entry>
      <entry> <code>__cpp_lib_math_constants &gt;= 201907L</code> </entry>
    </row>

    <row>
      <entry> std::source_location </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1208r6.pdf">
        P1208R6 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry>
        <code>__cpp_lib_source_location &gt;= 201907L</code>
      </entry>
    </row>

    <row>
      <entry> Efficient access to std::basic_stringbuf's Buffer </entry>
      <entry>
        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0408r7.pdf">
        P0408R7 </link>
      </entry>
      <entry align="center"> 11.1 </entry>
      <entry />
    </row>

  </tbody>
</tgroup>
</table>

<para>
Note 1: This feature is supported in older releases but the
<code>__cpp_lib</code> macro is not defined to the right value
(or not defined at all) until the version shown in parentheses.
</para>

<para>
Note 2: The C++20 calendar types are supported since 11.1,
time zones and UTC are supported since 13.1,
and <function>chrono::parse</function> is supported since 14.1.
</para>

</section>