libstdc++-v3/doc/xml/manual/status_cxx2020.xml

   1 <section xmlns="http://docbook.org/ns/docbook" version="5.0"
   2    xml:id="status.iso.2020" xreflabel="Status C++ 2020">
   3 <?dbhtml filename="status_iso_cxx2020.html"?>
   4
   5 <info><title>C++ 2020</title>
   6   <keywordset>
   7     <keyword>ISO C++</keyword>
   8     <keyword>2020</keyword>
   9   </keywordset>
  10 </info>
  11
  12 <para>
  13 In this implementation the <literal>-std=gnu++2a</literal> or
  14 <literal>-std=c++2a</literal> flag must be used to enable language
  15 and library
  16 features. See <link linkend="manual.intro.using.flags">dialect</link>
  17 options. The pre-defined symbol
  18 <constant>__cplusplus</constant> is used to check for the
  19 presence of the required flag.
  20 </para>
  21
  22 <para>
  23 This section describes the C++20 and library TS support in mainline GCC,
  24 not in any particular release.
  25 </para>
  26
  27 <para>
  28 The following table lists new library features that have been accepted into
  29 the C++20 working draft. The "Proposal" column provides a link to the
  30 ISO C++ committee proposal that describes the feature, while the "Status"
  31 column indicates the first version of GCC that contains an implementation of
  32 this feature (if it has been implemented).
  33 A dash (&#x2014;) in the status column indicates that the changes in the proposal
  34 either do not affect the code in libstdc++, or the changes are not required for conformance.
  35 The "SD-6 Feature Test / Notes" column shows the corresponding macro or header from
  36 <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:
  37 Feature-testing recommendations for C++</link> (where applicable)
  38 or any notes about the implementation.
  39 </para>
  40
  41 <table frame="all" xml:id="table.cxx20_features">
  42 <title>C++ 2020 Library Features</title>
  43
  44 <tgroup cols="4" align="left" colsep="0" rowsep="1">
  45 <colspec colname="c1"/>
  46 <colspec colname="c2"/>
  47 <colspec colname="c3"/>
  48 <colspec colname="c4"/>
  49   <thead>
  50     <row>
  51       <entry>Library Feature</entry>
  52       <entry>Proposal</entry>
  53       <entry>Status</entry>
  54       <entry>SD-6 Feature Test / Notes</entry>
  55     </row>
  56   </thead>
  57
  58   <tbody>
  59
  60     <row>
  61       <entry namest="c1" nameend="c4" align="left">
  62         <emphasis role="bold">Compile-time programming</emphasis>
  63       </entry>
  64     </row>
  65
  66     <row>
  67       <entry>  Add constexpr modifiers to functions in <code>&lt;algorithm&gt;</code> and <code>&lt;utility&gt;</code> Headers </entry>
  68       <entry>
  69         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0202r3.html">
  70         P0202R3 </link>
  71       </entry>
  72       <entry align="center"> 10.1 </entry>
  73       <entry> <code>__cpp_lib_constexpr_algorithms &gt;= 201703L</code> </entry>
  74     </row>
  75
  76     <row>
  77       <entry>  Constexpr for <code>swap</code> and swap related functions </entry>
  78       <entry>
  79         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0879r0.html">
  80         P0879R0 </link>
  81       </entry>
  82       <entry align="center"> 10.1 </entry>
  83       <entry> <code>__cpp_lib_constexpr_algorithms &gt;= 201806L</code> </entry>
  84     </row>
  85
  86     <row>
  87       <entry>  Constexpr for <code>std::complex</code> </entry>
  88       <entry>
  89         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0415r1.html">
  90         P0415R1 </link>
  91       </entry>
  92       <entry align="center"> 9.1 </entry>
  93       <entry> <code>__cpp_lib_constexpr_complex &gt;= 201711L</code> (since 9.4, see Note 1) </entry>
  94     </row>
  95
  96     <row>
  97       <entry>  P0595R2 <code>std::is_constant_evaluated()</code> </entry>
  98       <entry>
  99         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0595r2.html">
 100         P0595R2 </link>
 101       </entry>
 102       <entry align="center"> 9.1 </entry>
 103       <entry> <code>__cpp_lib_is_constant_evaluated &gt;= 201811L</code> </entry>
 104     </row>
 105
 106     <row>
 107       <entry>  More constexpr containers </entry>
 108       <entry>
 109         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0784r7.html">
 110         P0784R7 </link>
 111       </entry>
 112       <entry align="center"> 10.1 </entry>
 113       <entry> <code>__cpp_lib_constexpr_dynamic_alloc &gt;= 201907L</code> </entry>
 114     </row>
 115
 116     <row>
 117       <?dbhtml bgcolor="#C8B0B0" ?>
 118       <entry>  Making <code>std::string</code> constexpr </entry>
 119       <entry>
 120         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0980r1.pdf">
 121         P0980R1 </link>
 122       </entry>
 123       <entry/>
 124       <entry> <code>__cpp_lib_constexpr_string &gt;= 201907L</code> </entry>
 125     </row>
 126
 127     <row>
 128       <?dbhtml bgcolor="#C8B0B0" ?>
 129       <entry>  Making <code>std::vector</code> constexpr </entry>
 130       <entry>
 131         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1004r2.pdf">
 132         P1004R2 </link>
 133       </entry>
 134       <entry/>
 135       <entry> <code>__cpp_lib_constexpr_vector &gt;= 201907L</code> </entry>
 136     </row>
 137
 138     <row>
 139       <entry>  Constexpr in <code>std::pointer_traits</code> </entry>
 140       <entry>
 141         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1006r1.pdf">
 142         P1006R1 </link>
 143       </entry>
 144       <entry align="center"> 9.1 </entry>
 145       <entry> <code>__cpp_lib_constexpr_memory &gt;= 201811L</code> (since 9.4, see Note 1) </entry>
 146     </row>
 147
 148     <row>
 149       <entry>  constexpr for <code>&lt;numeric&gt;</code> algorithms </entry>
 150       <entry>
 151         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1645r1.html">
 152         P1645R1 </link>
 153       </entry>
 154       <entry align="center"> 10.1 </entry>
 155       <entry> <code>__cpp_lib_constexpr_numeric &gt;= 201911L</code> </entry>
 156     </row>
 157
 158     <row>
 159       <entry>  Constexpr iterator requirements </entry>
 160       <entry>
 161         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0858r0.html">
 162         P0858R0 </link>
 163       </entry>
 164       <entry align="center"> 9.1 </entry>
 165       <entry>
 166         <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
 167         <row><entry> <code>__cpp_lib_array_constexpr &gt;= 201803L</code> </entry></row>
 168         <row><entry> <code>__cpp_lib_string_view &gt;= 201803L</code> </entry></row>
 169         <row><entry> (both since 9.4, see Note 1) </entry></row>
 170         </tbody></tgroup></informaltable>
 171       </entry>
 172     </row>
 173
 174     <row>
 175       <entry>  <code>constexpr</code> comparison operators for <code>std::array</code> </entry>
 176       <entry>
 177         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1023r0.pdf">
 178         P1023R0 </link>
 179       </entry>
 180       <entry align="center"> 10.1 </entry>
 181       <entry> <code>__cpp_lib_array_constexpr &gt;= 201806</code> </entry>
 182     </row>
 183
 184     <row>
 185       <entry>  Misc constexpr bits </entry>
 186       <entry>
 187         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1032r1.html">
 188         P1032R1 </link>
 189       </entry>
 190       <entry align="center"> 10.1 </entry>
 191       <entry>
 192         <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
 193         <row><entry> <code>__cpp_lib_array_constexpr &gt;= 201811L</code> </entry></row>
 194         <row><entry> <code>__cpp_lib_constexpr_functional &gt;= 201811L</code> </entry></row>
 195         <row><entry> <code>__cpp_lib_constexpr_iterator &gt;= 201811L</code> </entry></row>
 196         <row><entry> <code>__cpp_lib_constexpr_string_view &gt;= 201811L</code> </entry></row>
 197         <row><entry> <code>__cpp_lib_constexpr_tuple &gt;= 201811L</code> </entry></row>
 198         <row><entry> <code>__cpp_lib_constexpr_utility &gt;= 201811L</code> </entry></row>
 199         </tbody></tgroup></informaltable>
 200       </entry>
 201     </row>
 202
 203     <row>
 204       <entry>  <code>constexpr <emphasis>INVOKE</emphasis></code> </entry>
 205       <entry>
 206         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1065r2.html">
 207         P1065R2 </link>
 208       </entry>
 209       <entry align="center"> 10.1 </entry>
 210       <entry> <code>__cpp_lib_constexpr_functional &gt;= 201907L</code> </entry>
 211     </row>
 212
 213
 214     <row>
 215       <entry>  Transformation Trait <code>remove_cvref</code> </entry>
 216       <entry>
 217         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0550r2.pdf">
 218         P0550R2 </link>
 219       </entry>
 220       <entry align="center"> 9.1 </entry>
 221       <entry> <code>__cpp_lib_remove_cvref &gt;= 201711L</code> (since 9.4, see Note 1) </entry>
 222     </row>
 223
 224     <row>
 225       <entry>  Implicit conversion traits and utility functions </entry>
 226       <entry>
 227         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0758r1.html">
 228         P0758R1 </link>
 229       </entry>
 230       <entry align="center"> 9.1 </entry>
 231       <entry> <code>__cpp_lib_is_nothrow_convertible &gt;= 201806L</code>  (since 9.4, see Note 1) </entry>
 232     </row>
 233
 234     <row>
 235       <entry>  The <code>identity</code> metafunction </entry>
 236       <entry>
 237         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0887r1.pdf">
 238         P0887R1 </link>
 239       </entry>
 240       <entry align="center"> 9.1 </entry>
 241       <entry> <code>__cpp_lib_type_identity &gt;= 201806L</code> (since 9.4, see Note 1) </entry>
 242     </row>
 243
 244
 245     <row>
 246       <entry>  <code>unwrap_ref_decay</code> and <code>unwrap_reference</code> </entry>
 247       <entry>
 248         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0318r1.pdf">
 249         P0318R1 </link>
 250       </entry>
 251       <entry align="center"> 9.1 </entry>
 252       <entry> <code>__cpp_lib_unwrap_ref &gt;= 201811L</code> (since 9.4, see Note 1) </entry>
 253     </row>
 254
 255     <row>
 256       <?dbhtml bgcolor="#B0B0B0" ?>
 257       <entry>  Improving Completeness Requirements for Type Traits </entry>
 258       <entry>
 259         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1285r0.pdf">
 260         P1285R0 </link>
 261       </entry>
 262       <entry align="center"> Partial </entry>
 263       <entry />
 264     </row>
 265
 266     <row>
 267       <entry>  Missing feature test macros </entry>
 268       <entry>
 269         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1353r0.html">
 270         P1353R0 </link>
 271       </entry>
 272       <entry align="center"> 9.1 </entry>
 273       <entry />
 274     </row>
 275
 276     <row>
 277       <entry> Making std::underlying_type SFINAE-friendly </entry>
 278       <entry>
 279         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0340r3.html">
 280         P0340R3 </link>
 281       </entry>
 282       <entry align="center"> 9.1 </entry>
 283       <entry />
 284     </row>
 285
 286     <row>
 287       <entry> Traits for [Un]bounded Arrays </entry>
 288       <entry>
 289         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1357r1.pdf">
 290         P1357R1 </link>
 291       </entry>
 292       <entry align="center"> 9.1 </entry>
 293       <entry> <code>__cpp_lib_bounded_array_traits &gt;= 201902L</code> </entry>
 294     </row>
 295
 296     <row>
 297       <?dbhtml bgcolor="#C8B0B0" ?>
 298       <entry> Layout-compatibility and pointer-interconvertibility traits </entry>
 299       <entry>
 300         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0466r5.pdf">
 301         P0466R5 </link>
 302       </entry>
 303       <entry align="center"> </entry>
 304       <entry>
 305         <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
 306         <row><entry> <code>__cpp_lib_is_layout_compatible &gt;= 201907L</code> </entry></row>
 307         <row><entry> <code>__cpp_lib_is_pointer_interconvertible &gt;= 201907L</code> </entry></row>
 308         </tbody></tgroup></informaltable>
 309       </entry>
 310     </row>
 311
 312     <row>
 313       <entry>  Integrating feature-test macros into the C++ WD </entry>
 314       <entry>
 315         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0941r2.html">
 316         P0941R2 </link>
 317       </entry>
 318       <entry align="center"> 5.1 </entry>
 319       <entry />
 320     </row>
 321
 322     <row>
 323       <entry>  <code>&lt;version&gt;</code> </entry>
 324       <entry>
 325         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0754r2.pdf">
 326         P0754R2 </link>
 327       </entry>
 328       <entry align="center"> 9.1 </entry>
 329       <entry> <code>__has_include(&lt;version&gt;)</code> </entry>
 330     </row>
 331
 332
 333     <row>
 334       <entry namest="c1" nameend="c4" align="left">
 335         <emphasis role="bold">Synchronization</emphasis>
 336       </entry>
 337     </row>
 338
 339     <row>
 340       <entry>  Atomic Ref </entry>
 341       <entry>
 342         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0019r8.html">
 343         P0019R8 </link>
 344       </entry>
 345       <entry align="center"> 10.1 </entry>
 346       <entry> <code>__cpp_lib_atomic_ref &gt;= 201806L</code> </entry>
 347     </row>
 348
 349     <row>
 350       <entry>  Floating Point Atomic </entry>
 351       <entry>
 352         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0020r6.html">
 353         P0020R6 </link>
 354       </entry>
 355       <entry align="center"> 10.1 </entry>
 356       <entry> <code>__cpp_lib_atomic_float &gt;= 201711L</code> </entry>
 357     </row>
 358
 359     <row>
 360       <entry>  C++ Synchronized Buffered Ostream </entry>
 361       <entry>
 362         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0053r7.pdf">
 363         P0053R7 </link>
 364       </entry>
 365       <entry align="center"> 11 </entry>
 366       <entry> <code>__cpp_lib_syncbuf &gt;= 201711L</code> </entry>
 367     </row>
 368
 369     <row>
 370       <entry>  Manipulators for C++ Synchronized Buffered Ostream </entry>
 371       <entry>
 372         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0753r2.pdf">
 373         P0753R2 </link>
 374       </entry>
 375       <entry align="center"> 11 </entry>
 376       <entry> <code>__cpp_lib_syncbuf &gt;= 201803L</code> </entry>
 377     </row>
 378
 379     <row>
 380       <entry>  Make <code>std::memory_order</code> a scoped enumeration </entry>
 381       <entry>
 382         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0439r0.html">
 383         P0439R0 </link>
 384       </entry>
 385       <entry align="center"> 9.1 </entry>
 386       <entry />
 387     </row>
 388
 389     <row>
 390       <?dbhtml bgcolor="#C8B0B0" ?>
 391       <entry>  The Curious Case of Padding Bits, Featuring Atomic Compare-and-Exchange </entry>
 392       <entry>
 393         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0528r3.html">
 394         P0528R3 </link>
 395       </entry>
 396       <entry align="center"> </entry>
 397       <entry />
 398     </row>
 399
 400     <row>
 401       <?dbhtml bgcolor="#C8B0B0" ?>
 402       <entry>  Atomic <code>shared_ptr</code> </entry>
 403       <entry>
 404         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0718r2.html">
 405         P0718R2 </link>
 406       </entry>
 407       <entry align="center"> </entry>
 408       <entry> <code> __cpp_lib_atomic_shared_ptr &gt;= 201711L</code> </entry>
 409     </row>
 410
 411     <row>
 412       <entry> std::stop_token and std::jthread </entry>
 413       <entry>
 414         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0660r10.pdf">
 415         P0660R10 </link>
 416       </entry>
 417       <entry align="center"> 10.1 </entry>
 418       <entry> <code>__cpp_lib_jthread &gt;= 201907L</code> </entry>
 419     </row>
 420
 421     <row>
 422       <entry> Rename <code>condition_variable_any</code> interruptible wait methods </entry>
 423       <entry>
 424         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1869r1.html">
 425         P1869R1 </link>
 426       </entry>
 427       <entry align="center"> 10.1 </entry>
 428       <entry> <code>__cpp_lib_jthread &gt;= 201911L</code> </entry>
 429     </row>
 430
 431     <row>
 432       <entry> Atomic waiting and notifying, std::semaphore, std::latch and std::barrier </entry>
 433       <entry>
 434         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1135r6.html">
 435         P1135R6 </link>
 436       </entry>
 437       <entry align="center"> 11.1 </entry>
 438       <entry>
 439         <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
 440         <row><entry> <code>__cpp_lib_atomic_lock_free_type_aliases &gt;= 201907L</code> </entry></row>
 441         <row><entry> <code>__cpp_lib_atomic_flag_test &gt;= 201907L</code> </entry></row>
 442         <row><entry> <code>__cpp_lib_atomic_wait &gt;= 201907L</code> </entry></row>
 443         <row><entry> <code>__cpp_lib_semaphore &gt;= 201907L</code> </entry></row>
 444         <row><entry> <code>__cpp_lib_latch &gt;= 201907L</code> </entry></row>
 445         <row><entry> <code>__cpp_lib_barrier &gt;= 201907L</code> </entry></row>
 446         </tbody></tgroup></informaltable>
 447       </entry>
 448     </row>
 449
 450     <row>
 451       <entry> Fixing Atomic Initialization </entry>
 452       <entry>
 453         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0883r2.pdf">
 454         P0883R2 </link>
 455       </entry>
 456       <entry align="center"> 10.1 </entry>
 457       <entry> <code>__cpp_lib_atomic_value_initialization &gt;= 201911L</code> </entry>
 458     </row>
 459
 460
 461
 462     <row>
 463       <entry namest="c1" nameend="c4" align="left">
 464         <emphasis role="bold">Ranges and Concepts</emphasis>
 465       </entry>
 466     </row>
 467
 468     <row>
 469       <entry>  Standard Library Concepts </entry>
 470       <entry>
 471         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0898r3.pdf">
 472         P0898R3 </link>
 473       </entry>
 474       <entry align="center"> 10.1 </entry>
 475       <entry> <code>__cpp_lib_concepts &gt;= 201806L</code> </entry>
 476     </row>
 477
 478     <row>
 479       <entry>  Rename concepts to standard_case for C++20, while we still can </entry>
 480       <entry>
 481         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1754r1.pdf">
 482         P1754R1 </link>
 483       </entry>
 484       <entry align="center"> 10.1 </entry>
 485       <entry> <code>__cpp_lib_concepts &gt;= 201907L</code> </entry>
 486     </row>
 487
 488     <row>
 489       <entry>  Wording for <emphasis><code>boolean-testable</code></emphasis> </entry>
 490       <entry>
 491         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1964r2.html">
 492         P1964R2 </link>
 493       </entry>
 494       <entry align="center"> 10.1 </entry>
 495       <entry> <code>__cpp_lib_concepts &gt;= 202002L</code> </entry>
 496     </row>
 497
 498     <row>
 499       <entry>  The One Ranges Proposal </entry>
 500       <entry>
 501         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0896r4.pdf">
 502         P0896R4 </link>
 503       </entry>
 504       <entry align="center"> 10.1 </entry>
 505       <entry> <code>__cpp_lib_ranges &gt;= 201811L</code> </entry>
 506     </row>
 507
 508     <row>
 509       <entry>  Input Range Adaptors </entry>
 510       <entry>
 511         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1035r7.pdf">
 512         P1035R7 </link>
 513       </entry>
 514       <entry align="center"> 10.1 </entry>
 515       <entry> <code>__cpp_lib_ranges &gt;= 201907L</code> </entry>
 516     </row>
 517
 518     <row>
 519       <entry>  <code>ranges</code> compare algorithm are over-constrained </entry>
 520       <entry>
 521         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1716r3.html">
 522         P1716R3 </link>
 523       </entry>
 524       <entry align="center"> 10.1 </entry>
 525       <entry> <code>__cpp_lib_ranges &gt;= 201911L</code> </entry>
 526     </row>
 527
 528     <row>
 529       <entry>  Remove CommonReference requirement from StrictWeakOrdering (a.k.a Fixing Relations) </entry>
 530       <entry>
 531         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1248r1.html">
 532         P1248R1 </link>
 533       </entry>
 534       <entry align="center"> 10.1 </entry>
 535       <entry />
 536     </row>
 537
 538     <row>
 539       <entry> Ranges Design Cleanup </entry>
 540       <entry>
 541         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1252r2.pdf">
 542         P1252R2 </link>
 543       </entry>
 544       <entry align="center"> 10.1 </entry>
 545       <entry />
 546     </row>
 547
 548
 549
 550     <row>
 551       <entry namest="c1" nameend="c4" align="left">
 552         <emphasis role="bold">Time, dates, calendars, time zones</emphasis>
 553       </entry>
 554     </row>
 555
 556     <row>
 557       <?dbhtml bgcolor="#C8B0B0" ?>
 558       <entry>  Extending chrono to Calendars and Time Zones </entry>
 559       <entry>
 560         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0355r7.html">
 561         P0355R7 </link>
 562       </entry>
 563       <entry/>
 564       <entry> <code>__cpp_lib_chrono &gt;= 201803L</code> </entry>
 565     </row>
 566
 567     <row>
 568       <?dbhtml bgcolor="#C8B0B0" ?>
 569       <entry> Miscellaneous minor fixes for chrono </entry>
 570       <entry>
 571         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1466r3.html">
 572         P1466R3 </link>
 573       </entry>
 574       <entry/>
 575       <entry> <code>__cpp_lib_chrono &gt;= 201907L</code> </entry>
 576     </row>
 577
 578     <row>
 579       <entry>  <code>&lt;chrono&gt;</code> <code>zero()</code>, <code>min()</code>, and <code>max()</code> should be <code>noexcept</code> </entry>
 580       <entry>
 581         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0972r0.pdf">
 582         P0972R0 </link>
 583       </entry>
 584       <entry align="center"> 9.1 </entry>
 585       <entry />
 586     </row>
 587
 588
 589     <row>
 590       <entry namest="c1" nameend="c4" align="left">
 591         <emphasis role="bold">Three-way comparison</emphasis>
 592       </entry>
 593     </row>
 594
 595     <row>
 596       <entry>  Library Support for the Spaceship (Comparison) Operator </entry>
 597       <entry>
 598         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0768r1.pdf">
 599         P0768R1 </link>
 600       </entry>
 601       <entry align="center"> 10.1 </entry>
 602       <entry> <code>__cpp_lib_three_way_comparison &gt;= 201711L</code> </entry>
 603     </row>
 604
 605     <row>
 606       <entry>  Symmetry for spaceship </entry>
 607       <entry>
 608         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0905r1.html">
 609         P0905R1 </link>
 610       </entry>
 611       <entry align="center"> 10.1 </entry>
 612       <entry />
 613     </row>
 614
 615     <row>
 616       <entry> Adding &lt;=&gt; to the standard library </entry>
 617       <entry>
 618         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1614r2.html">
 619         P1614R2 </link>
 620       </entry>
 621       <entry align="center"> 10.1 </entry>
 622       <entry>
 623         <code>__cpp_lib_three_way_comparison &gt;= 201907L</code>
 624       </entry>
 625     </row>
 626
 627
 628     <row>
 629       <entry namest="c1" nameend="c4" align="left">
 630         <emphasis role="bold">Strings and text</emphasis>
 631       </entry>
 632     </row>
 633
 634     <row>
 635       <entry>  <code>string::reserve</code> Should Not Shrink </entry>
 636       <entry>
 637         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0966r1.html">
 638         P0966R1 </link>
 639       </entry>
 640       <entry align="center"> 11 </entry>
 641       <entry />
 642     </row>
 643
 644     <row>
 645       <entry>  <code>char8_t</code>: A type for UTF-8 characters and strings </entry>
 646       <entry>
 647         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0482r6.html">
 648         P0482R6 </link>
 649       </entry>
 650       <entry align="center"> 9.1 </entry>
 651       <entry> <code>__cpp_lib_char8_t &gt;= 201811L</code> </entry>
 652     </row>
 653
 654     <row>
 655       <entry>  <code>char8_t</code> backward compatibility remediation </entry>
 656       <entry>
 657         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1423r3.html">
 658         P1423R3 </link>
 659       </entry>
 660       <entry align="center"> 10.1 </entry>
 661       <entry> <code>__cpp_lib_char8_t &gt;= 201907L</code> </entry>
 662     </row>
 663
 664     <row>
 665       <?dbhtml bgcolor="#C8B0B0" ?>
 666       <entry> Text formatting </entry>
 667       <entry>
 668         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0645r10.html">
 669         P0645R10 </link>
 670       </entry>
 671       <entry align="center"> </entry>
 672       <entry>
 673         <code>__cpp_lib_format &gt;= 201907L</code>
 674       </entry>
 675     </row>
 676
 677     <row>
 678       <?dbhtml bgcolor="#C8B0B0" ?>
 679       <entry> Integration of chrono with text formatting </entry>
 680       <entry>
 681         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1361r2.pdf">
 682         P1361R2 </link>
 683       </entry>
 684       <entry align="center"> </entry>
 685       <entry>
 686         <code>__cpp_lib_format &gt;= 201907L</code>
 687       </entry>
 688     </row>
 689
 690     <row>
 691       <?dbhtml bgcolor="#C8B0B0" ?>
 692       <entry> Printf corner cases in <code>std::format</code> </entry>
 693       <entry>
 694         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1652r1.html">
 695         P1652R1 </link>
 696       </entry>
 697       <entry align="center"> </entry>
 698       <entry>
 699         <code>__cpp_lib_format &gt;= 201907L</code>
 700       </entry>
 701     </row>
 702
 703     <row>
 704       <entry>  String Prefix and Suffix Checking </entry>
 705       <entry>
 706         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0457r2.html">
 707         P0457R2 </link>
 708       </entry>
 709       <entry align="center"> 9.1 </entry>
 710       <entry> <code>__cpp_lib_starts_ends_with &gt;= 201711L</code> (since 9.4, see Note 1) </entry>
 711     </row>
 712
 713     <row>
 714       <?dbhtml bgcolor="#C8B0B0" ?>
 715       <entry>  Update The Reference To The Unicode Standard </entry>
 716       <entry>
 717         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1025r1.html">
 718         P1025R1 </link>
 719       </entry>
 720       <entry align="center"> </entry>
 721       <entry />
 722     </row>
 723
 724
 725     <row>
 726       <entry namest="c1" nameend="c4" align="left">
 727         <emphasis role="bold">Containers</emphasis>
 728       </entry>
 729     </row>
 730
 731     <row>
 732       <entry> span: bounds-safe views for sequences of objects </entry>
 733       <entry>
 734         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0122r7.pdf">
 735         P0122R7 </link>
 736       </entry>
 737       <entry align="center"> 10.1 </entry>
 738       <entry> <code>__cpp_lib_span &gt;= 201803L</code> </entry>
 739     </row>
 740
 741     <row>
 742       <entry>
 743         Usability Enhancements for <classname>std::span</classname>
 744       </entry>
 745       <entry>
 746         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1024r3.pdf">
 747         P1024R3 </link>
 748       </entry>
 749       <entry align="center"> 10.1 </entry>
 750       <entry> <code>__cpp_lib_span &gt;= 201902L</code> </entry>
 751     </row>
 752
 753     <row>
 754       <entry>  Should Span be Regular? </entry>
 755       <entry>
 756         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1085r2.md">
 757         P1085R2 </link>
 758       </entry>
 759       <entry align="center"> 10.1 </entry>
 760       <entry/>
 761     </row>
 762
 763     <row>
 764       <entry> Fixed-size <code>&lt;span&gt;</code> construction from dynamic range </entry>
 765       <entry>
 766         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1976r2.html">
 767         P1976R2 </link>
 768       </entry>
 769       <entry align="center"> 10.1 </entry>
 770       <entry> <code>__cpp_lib_span &gt;= 202002L</code> </entry>
 771     </row>
 772
 773     <row>
 774       <entry> <code>std::to_array</code> </entry>
 775       <entry>
 776         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0325r4.html">
 777         P0325R4 </link>
 778       </entry>
 779       <entry align="center"> 10.1 </entry>
 780       <entry> <code>__cpp_lib_to_array &gt;= 201907L</code> </entry>
 781     </row>
 782
 783     <row>
 784       <entry>  Checking for Existence of an Element in Associative Containers </entry>
 785       <entry>
 786         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0458r2.html">
 787         P0458R2 </link>
 788       </entry>
 789       <entry align="center"> 9.1 </entry>
 790       <entry />
 791     </row>
 792
 793     <row>
 794       <?dbhtml bgcolor="#C8B0B0" ?>
 795       <entry>  Comparing Unordered Containers </entry>
 796       <entry>
 797         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0809r0.pdf">
 798         P0809R0 </link>
 799       </entry>
 800       <entry align="center"> </entry>
 801       <entry />
 802     </row>
 803
 804     <row>
 805       <entry>  Heterogeneous lookup for unordered containers </entry>
 806       <entry>
 807         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0919r3.html">
 808         P0919R3 </link>
 809       </entry>
 810       <entry align="center"> 11.1 </entry>
 811       <entry> <code>__cpp_lib_generic_unordered_lookup &gt;= 201811</code> </entry>
 812     </row>
 813
 814     <row>
 815       <entry> Refinement Proposal for P0919 </entry>
 816       <entry>
 817         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1690r1.html">
 818         P1690R1 </link>
 819       </entry>
 820       <entry align="center"> 11.1 </entry>
 821       <entry/>
 822     </row>
 823
 824     <row>
 825       <entry>  Adopt Consistent Container Erasure from Library Fundamentals 2 for C++20 </entry>
 826       <entry>
 827         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1209r0.html">
 828         P1209R0 </link>
 829       </entry>
 830       <entry align="center"> 9.1 </entry>
 831       <entry> <code>__cpp_lib_erase_if &gt;= 201811L</code> </entry>
 832     </row>
 833
 834     <row>
 835       <entry>  Improving the Return Value of Erase-Like Algorithms </entry>
 836       <entry>
 837         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0646r1.pdf">
 838         P0646R1 </link>
 839       </entry>
 840       <entry align="center"> 9.1 </entry>
 841       <entry> <code>__cpp_lib_list_remove_return_type &gt;= 201806L</code> </entry>
 842     </row>
 843
 844     <row>
 845       <entry>  Improving the Return Value of Erase-Like Algorithms II: Free <code>erase</code>/<code>erase_if</code> </entry>
 846       <entry>
 847         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1115r3.pdf">
 848         P1115R3 </link>
 849       </entry>
 850       <entry align="center"> 9.1 </entry>
 851       <entry>
 852         <informaltable colsep="0" rowsep="0" rowheader="norowheader" frame="none"><tgroup cols="1"><tbody>
 853         <row><entry> <code>__cpp_lib_erase_if &gt;= 202002L</code> </entry></row>
 854         <row><entry> (defined to <code>201900L</code> for GCC 9.1 and 9.2 so use <code>&gt; 201811L</code>) </entry></row>
 855         </tbody></tgroup></informaltable>
 856       </entry>
 857     </row>
 858
 859     <row>
 860       <entry> Signed ssize() functions, unsigned size() functions </entry>
 861       <entry>
 862         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1227r2.html">
 863         P1227R2 </link>
 864       </entry>
 865       <entry align="center"> 10.1 </entry>
 866       <entry> <code>__cpp_lib_ssize &gt;= 201902L</code> </entry>
 867     </row>
 868
 869
 870     <row>
 871       <entry namest="c1" nameend="c4" align="left">
 872         <emphasis role="bold">Memory management</emphasis>
 873       </entry>
 874     </row>
 875
 876     <row>
 877       <entry>  Utility to convert a pointer to a raw pointer </entry>
 878       <entry>
 879         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0653r2.html">
 880         P0653R2 </link>
 881       </entry>
 882       <entry align="center"> 8.1 </entry>
 883       <entry> <code>__cpp_lib_to_address &gt;= 201711L</code> (since 9.4, see Note 1) </entry>
 884     </row>
 885
 886     <row>
 887       <?dbhtml bgcolor="#C8B0B0" ?>
 888       <entry>  Extending <code>make_shared</code> to Support Arrays </entry>
 889       <entry>
 890         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0674r1.html">
 891         P0674R1 </link>
 892       </entry>
 893       <entry align="center"> </entry>
 894       <entry> <code>__cpp_lib_shared_ptr_arrays &gt;= 201707L</code> </entry>
 895     </row>
 896
 897     <row>
 898       <entry>  Efficient sized delete for variable sized classes </entry>
 899       <entry>
 900         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0722r3.html">
 901         P0722R3 </link>
 902       </entry>
 903       <entry align="center"> 9.1 </entry>
 904       <entry> <code>__cpp_lib_destroying_delete &gt;= 201806L</code> </entry>
 905     </row>
 906
 907     <row>
 908       <entry>  Utility functions to implement uses-allocator construction </entry>
 909       <entry>
 910         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0591r4.pdf">
 911         P0591R4 </link>
 912       </entry>
 913       <entry align="center"> 9.1 </entry>
 914       <entry>
 915         <code>std::scoped_allocator_adaptor</code> changes missing in 9.1.0
 916       </entry>
 917     </row>
 918
 919     <row>
 920       <entry>  <code>std::assume_aligned</code> </entry>
 921       <entry>
 922         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1007r3.pdf">
 923         P1007R3 </link>
 924       </entry>
 925       <entry align="center"> 9.1 </entry>
 926       <entry> <code>__cpp_lib_assume_aligned &gt;= 201811L</code> (since 9.4, see Note 1) </entry>
 927     </row>
 928
 929     <row>
 930       <?dbhtml bgcolor="#C8B0B0" ?>
 931       <entry>  Smart pointer creation with default initialization </entry>
 932       <entry>
 933         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1020r1.html">
 934         P1020R1 </link>
 935       </entry>
 936       <entry align="center"> </entry>
 937       <entry> <code>__cpp_lib_smart_ptr_for_overwrite &gt;= 201811L</code> </entry>
 938     </row>
 939
 940     <row>
 941       <entry>  Make stateful allocator propagation more consistent for <code>operator+(basic_string)</code> </entry>
 942       <entry>
 943         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1165r1.html">
 944         P1165R1 </link>
 945       </entry>
 946       <entry align="center"> 10.1 </entry>
 947       <entry />
 948     </row>
 949
 950     <row>
 951       <entry>
 952         <classname>polymorphic_allocator&lt;&gt;</classname> as a vocabulary type
 953       </entry>
 954       <entry>
 955         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0339r6.pdf">
 956         P0339R6 </link>
 957       </entry>
 958       <entry align="center"> 9.1 </entry>
 959       <entry>
 960       <code>__cpp_lib_polymorphic_allocator &gt;= 201902L</code> (since 9.4, see Note 1)
 961       </entry>
 962     </row>
 963
 964     <row>
 965       <entry>  LWG 2511: guaranteed copy elision for piecewise construction </entry>
 966       <entry>
 967         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0475r1.html">
 968         P0475R1 </link>
 969       </entry>
 970       <entry align="center"> 7.1 </entry>
 971       <entry />
 972     </row>
 973
 974
 975     <row>
 976       <entry namest="c1" nameend="c4" align="left">
 977         <emphasis role="bold">Miscellaneous</emphasis>
 978       </entry>
 979     </row>
 980
 981     <row>
 982       <entry>  <code>nodiscard</code> in the Library </entry>
 983       <entry>
 984         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0600r1.pdf">
 985         P0600R1 </link>
 986       </entry>
 987       <entry align="center"> 9.1 </entry>
 988       <entry />
 989     </row>
 990
 991     <row>
 992       <entry>  de-pessimize legacy algorithms with <code>std::move</code> </entry>
 993       <entry>
 994         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0616r0.pdf">
 995         P0616R0 </link>
 996       </entry>
 997       <entry align="center"> 9.1 </entry>
 998       <entry />
 999     </row>
1000
1001     <row>
1002       <entry>  Deprecate POD </entry>
1003       <entry>
1004         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0767r1.html">
1005         P0767R1 </link>
1006       </entry>
1007       <entry align="center"> 10.1 </entry>
1008       <entry />
1009     </row>
1010
1011     <row>
1012       <entry>  Treating Unnecessary <code>decay</code> </entry>
1013       <entry>
1014         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0777r1.pdf">
1015         P0777R1 </link>
1016       </entry>
1017       <entry align="center"> 9.1 </entry>
1018       <entry />
1019     </row>
1020
1021     <row>
1022       <?dbhtml bgcolor="#C8B0B0" ?>
1023       <entry>  Thou Shalt Not Specialize std Function Templates! </entry>
1024       <entry>
1025         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0551r3.pdf">
1026         P0551R3 </link>
1027       </entry>
1028       <entry align="center"> </entry>
1029       <entry />
1030     </row>
1031
1032     <row>
1033       <entry>  Bit-casting object representations </entry>
1034       <entry>
1035         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0476r2.html">
1036         P0476R2 </link>
1037       </entry>
1038       <entry align="center"> 11 </entry>
1039       <entry> <code>__cpp_lib_bit_cast &gt;= 201806L</code> </entry>
1040     </row>
1041
1042     <row>
1043       <entry>  Integral power-of-2 operations </entry>
1044       <entry>
1045         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0556r3.html">
1046         P0556R3 </link>
1047       </entry>
1048       <entry align="center"> 9.1 </entry>
1049       <entry> <code>__cpp_lib_int_pow2 &gt;= 201806L</code> (since 9.4, see Note 1) </entry>
1050     </row>
1051
1052     <row>
1053       <entry> On the names of low-level bit manipulation functions </entry>
1054       <entry>
1055         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1956r1.pdf">
1056         P1956R1 </link>
1057       </entry>
1058       <entry align="center"> 10.1 </entry>
1059       <entry> <code>__cpp_lib_int_pow2 &gt;= 202002L</code> </entry>
1060     </row>
1061
1062     <row>
1063       <entry> Safe integral comparisons </entry>
1064       <entry>
1065         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p0586r2.html">
1066         P0586R2 </link>
1067       </entry>
1068       <entry align="center"> 10.1 </entry>
1069       <entry> <code>__cpp_lib_integer_comparison_functions &gt;= 202002L</code> </entry>
1070     </row>
1071
1072     <row>
1073       <?dbhtml bgcolor="#C8B0B0" ?>
1074       <entry>  Reviewing Deprecated Facilities of C++17 for C++20 </entry>
1075       <entry>
1076         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0619r4.html">
1077         P0619R4 </link>
1078       </entry>
1079       <entry align="center"> </entry>
1080       <entry />
1081     </row>
1082
1083     <row>
1084       <entry>  <code>fpos</code> Requirements </entry>
1085       <entry>
1086         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0759r1.html">
1087         P0759R1 </link>
1088       </entry>
1089       <entry align="center"> &#x2014; </entry>
1090       <entry />
1091     </row>
1092
1093     <row>
1094       <entry>  Add <code>shift</code> to <code>&lt;algorithm&gt;</code> </entry>
1095       <entry>
1096         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0769r2.pdf">
1097         P0769R2 </link>
1098       </entry>
1099       <entry align="center"> 10.1 </entry>
1100       <entry> <code>__cpp_lib_shift &gt;= 201806L</code> </entry>
1101     </row>
1102
1103     <row>
1104       <?dbhtml bgcolor="#C8B0B0" ?>
1105       <entry>  Standard Library Specification in a Concepts and Contracts World </entry>
1106       <entry>
1107         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0788r3.pdf">
1108         P0788R3 </link>
1109       </entry>
1110       <entry align="center"> </entry>
1111       <entry />
1112     </row>
1113
1114     <row>
1115       <entry>  <code>explicit(bool)</code> </entry>
1116       <entry>
1117         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0892r2.html">
1118         P0892R2 </link>
1119       </entry>
1120       <entry align="center"> &#x2014; </entry>
1121       <entry />
1122     </row>
1123
1124     <row>
1125       <entry>  Eradicating unnecessarily explicit default constructors from the standard library </entry>
1126       <entry>
1127         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0935r0.html">
1128         P0935R0 </link>
1129       </entry>
1130       <entry align="center"> 9.1 </entry>
1131       <entry />
1132     </row>
1133
1134     <row>
1135       <entry>  <code>std::function</code> move constructor should be <code>noexcept</code> </entry>
1136       <entry>
1137         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0771r1.pdf">
1138         P0771R1 </link>
1139       </entry>
1140       <entry align="center"> 7.2 </entry>
1141       <entry />
1142     </row>
1143
1144     <row>
1145       <entry>  Simplified partial function application </entry>
1146       <entry>
1147         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0356r5.html">
1148         P0356R5 </link>
1149       </entry>
1150       <entry align="center"> 9.1 </entry>
1151       <entry> <code>__cpp_lib_bind_front &gt;= 201811L</code> </entry>
1152     </row>
1153
1154     <row>
1155       <entry>  <code>bind_front</code> should not unwrap <code>reference_wrapper</code> </entry>
1156       <entry>
1157         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1651r0.html">
1158         P1651R0 </link>
1159       </entry>
1160       <entry align="center"> 9.3 </entry>
1161       <entry> <code>__cpp_lib_bind_front &gt;= 201907L</code> </entry>
1162     </row>
1163
1164     <row>
1165       <entry>  <code>reference_wrapper</code> for incomplete types </entry>
1166       <entry>
1167         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0357r3.html">
1168         P0357R3 </link>
1169       </entry>
1170       <entry align="center"> 9.1 </entry>
1171       <entry />
1172     </row>
1173
1174     <row>
1175       <entry>  Fixing <code>operator&gt;&gt;(basic_istream&amp;, CharT*)</code> (LWG 2499) </entry>
1176       <entry>
1177         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0487r1.html">
1178         P0487R1 </link>
1179       </entry>
1180       <entry align="center"> 11.1 </entry>
1181       <entry />
1182     </row>
1183
1184     <row>
1185       <entry>  <code>variant</code> and <code>optional</code> should propagate copy/move triviality </entry>
1186       <entry>
1187         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0602r4.html">
1188         P0602R4 </link>
1189       </entry>
1190       <entry align="center"> 8.3 </entry>
1191       <entry />
1192     </row>
1193
1194     <row>
1195       <entry>  A sane <code>variant</code> converting constructor </entry>
1196       <entry>
1197         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0608r3.html">
1198         P0608R3 </link>
1199       </entry>
1200       <entry align="center"> 10.1 </entry>
1201       <entry />
1202     </row>
1203
1204     <row>
1205       <entry>  <code>visit&lt;R&gt;</code>: Explicit Return Type for <code>visit</code> </entry>
1206       <entry>
1207         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0655r1.pdf">
1208         P0655R1 </link>
1209       </entry>
1210       <entry align="center"> 9.1 </entry>
1211       <entry />
1212     </row>
1213
1214     <row>
1215       <entry>  P0899R1 - LWG 3016 is not a defect </entry>
1216       <entry>
1217         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0899r1.html">
1218         P0899R1 </link>
1219       </entry>
1220       <entry align="center"> 7.1 </entry>
1221       <entry />
1222     </row>
1223
1224     <row>
1225       <entry>  Editorial Guidance for merging P0019r8 and P0528r3 </entry>
1226       <entry>
1227         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1123r0.html">
1228         P1123R0 </link>
1229       </entry>
1230       <entry align="center"> &#x2014; </entry>
1231       <entry />
1232     </row>
1233
1234     <row>
1235       <?dbhtml bgcolor="#C8B0B0" ?>
1236       <entry>  Cleaning up Clause 20 </entry>
1237       <entry>
1238         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1148r0.pdf">
1239         P1148R0 </link>
1240       </entry>
1241       <entry align="center"> </entry>
1242       <entry />
1243     </row>
1244
1245     <row>
1246       <?dbhtml bgcolor="#C8B0B0" ?>
1247       <entry>  Completing the Rebase of Library Fundamentals, Version 3, Working Draft </entry>
1248       <entry>
1249         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1210r0.html">
1250         P1210R0 </link>
1251       </entry>
1252       <entry align="center"> </entry>
1253       <entry />
1254     </row>
1255
1256     <row>
1257       <entry>  Alternative Wording for P0907R4 Signed Integers are Two's Complement </entry>
1258       <entry>
1259         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html">
1260         P1236R1 </link>
1261       </entry>
1262       <entry align="center"> &#x2014; </entry>
1263       <entry/>
1264     </row>
1265
1266     <row>
1267       <entry>
1268         I Stream, You Stream, We All Stream for
1269         <classname>istream_iterator</classname>
1270       </entry>
1271       <entry>
1272         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0738r2.html">
1273         P0738R2 </link>
1274       </entry>
1275       <entry align="center"> 10.1 </entry>
1276       <entry />
1277     </row>
1278
1279     <row>
1280       <entry>
1281         Mandating the Standard Library:
1282         Clause 16 - Language support library
1283       </entry>
1284       <entry>
1285         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1458r1.pdf">
1286         P1458R1 </link>
1287       </entry>
1288       <entry align="center"> &#x2014; </entry>
1289       <entry/>
1290     </row>
1291
1292     <row>
1293       <entry>
1294         Mandating the Standard Library:
1295         Clause 18 - Diagnostics library
1296       </entry>
1297       <entry>
1298         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1458r1.pdf">
1299         P1459R1 </link>
1300       </entry>
1301       <entry align="center"> &#x2014; </entry>
1302       <entry/>
1303     </row>
1304
1305     <row>
1306       <entry>
1307         Mandating the Standard Library:
1308         Clause 20 - Strings library
1309       </entry>
1310       <entry>
1311         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1462r1.html">
1312         P1462R1 </link>
1313       </entry>
1314       <entry align="center"> &#x2014; </entry>
1315       <entry/>
1316     </row>
1317
1318     <row>
1319       <entry>
1320         Mandating the Standard Library:
1321         Clause 21 - Containers library
1322       </entry>
1323       <entry>
1324         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1463r1.pdf">
1325         P1463R1 </link>
1326       </entry>
1327       <entry align="center"> 10.1 </entry>
1328       <entry/>
1329     </row>
1330
1331     <row>
1332       <?dbhtml bgcolor="#C8B0B0" ?>
1333       <entry>
1334         Mandating the Standard Library:
1335         Clause 22 - Iterators library
1336       </entry>
1337       <entry>
1338         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1464r1.pdf">
1339         P1464R1 </link>
1340       </entry>
1341       <entry align="center"> </entry>
1342       <entry />
1343     </row>
1344
1345     <row>
1346       <entry> Make <code>create_directory()</code> Intuitive </entry>
1347       <entry>
1348         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1164r1.pdf">
1349         P1164R1
1350   </link>
1351       </entry>
1352       <entry align="center"> 8.3 </entry>
1353       <entry> Treated as a DR for C++17 </entry>
1354     </row>
1355
1356     <row>
1357       <entry>
1358         Target Vectorization Policies from Parallelism V2 TS to C++20
1359       </entry>
1360       <entry>
1361         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1001r2.html">
1362         P1001R2 </link>
1363       </entry>
1364       <entry align="center"> 9.1 </entry>
1365       <entry> <code>__cpp_lib_execution &gt;= 201902L</code> (since 9.4, see Note 1)</entry>
1366     </row>
1367
1368     <row>
1369       <entry> Merge Coroutines TS into C++20 working draft </entry>
1370       <entry>
1371         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0912r5.html">
1372         P0912R5 </link>
1373       </entry>
1374       <entry align="center"> 10.1 </entry>
1375       <entry> <code>__cpp_lib_coroutines &gt;= 201902L</code> </entry>
1376     </row>
1377
1378     <row>
1379       <entry>  Endian just Endian </entry>
1380       <entry>
1381         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0463r1.html">
1382         P0463R1 </link>
1383       </entry>
1384       <entry align="center"> 8.1 </entry>
1385       <entry> <code>__cpp_lib_endian &gt;= 201907L</code> </entry>
1386     </row>
1387
1388     <row>
1389       <entry> Bit operations </entry>
1390       <entry>
1391         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0553r4.html">
1392         P0553R4 </link>
1393       </entry>
1394       <entry align="center"> 10.1 </entry>
1395       <entry> <code>__cpp_lib_bitops &gt;= 201907L</code> (since 9.4, see Note 1) </entry>
1396     </row>
1397
1398     <row>
1399       <entry>  Well-behaved interpolation for numbers and pointers </entry>
1400       <entry>
1401         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0811r3.html">
1402         P0811R3 </link>
1403       </entry>
1404       <entry align="center"> 9.1 </entry>
1405       <entry> <code>__cpp_lib_interpolate &gt;= 201902L</code> </entry>
1406     </row>
1407
1408     <row>
1409       <entry> Mathematical constants </entry>
1410       <entry>
1411         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0631r8.pdf">
1412         P0631R8 </link>
1413       </entry>
1414       <entry align="center"> 10.1 </entry>
1415       <entry> <code>__cpp_lib_math_constants &gt;= 201907L</code> </entry>
1416     </row>
1417
1418     <row>
1419       <entry> std::source_location </entry>
1420       <entry>
1421         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1208r6.pdf">
1422         P1208R6 </link>
1423       </entry>
1424       <entry align="center"> 11 </entry>
1425       <entry>
1426         <code>__cpp_lib_source_location &gt;= 201907L</code>
1427       </entry>
1428     </row>
1429
1430     <row>
1431       <entry> Efficient access to std::basic_stringbuf's Buffer </entry>
1432       <entry>
1433         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0408r7.pdf">
1434         P0408R7 </link>
1435       </entry>
1436       <entry align="center"> 11 </entry>
1437       <entry />
1438     </row>
1439
1440     <row>
1441       <?dbhtml bgcolor="#C8B0B0" ?>
1442       <entry> Avoid template bloat for <code>safe_ranges</code> in combination with ‘subrange-y’ view adaptors.</entry>
1443       <entry>
1444         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1739r4.html">
1445         P1739R4 </link>
1446       </entry>
1447       <entry align="center"> </entry>
1448       <entry />
1449     </row>
1450
1451   </tbody>
1452 </tgroup>
1453 </table>
1454
1455 <para>
1456 Note 1: This feature is supported in older releases but the
1457 <code>__cpp_lib</code> macro is not defined to the right value
1458 (or not defined at all) until the version shown in parentheses.
1459 </para>
1460
1461 </section>