libstdc++-v3/doc/xml/manual/status_cxx2017.xml

   1 <section xmlns="http://docbook.org/ns/docbook" version="5.0"
   2          xml:id="status.iso.2017" xreflabel="Status C++ 2017">
   3 <?dbhtml filename="status_iso_cxx2017.html"?>
   4
   5 <info><title>C++ 2017</title>
   6   <keywordset>
   7     <keyword>ISO C++</keyword>
   8     <keyword>2017</keyword>
   9   </keywordset>
  10 </info>
  11
  12 <para>
  13 In this implementation the <literal>-std=gnu++17</literal> or
  14 <literal>-std=c++17</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 GCC 9.1 was the first release with non-experimental C++17 support,
  21 so the API and ABI of features added in C++17 is only stable
  22 since that release.
  23 </para>
  24
  25 <para>
  26 This section describes the C++17 and library TS support in
  27 mainline GCC, not in any particular release.
  28 </para>
  29
  30 <para>
  31 The following table lists new library features that are included in
  32 the C++17 standard. The "Proposal" column provides a link to the
  33 ISO C++ committee proposal that describes the feature, while the "Status"
  34 column indicates the first version of GCC that contains an implementation of
  35 this feature (if it has been implemented).
  36 The "SD-6 Feature Test" column shows the corresponding macro or header from
  37 <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:
  38 Feature-testing recommendations for C++</link>.
  39 </para>
  40
  41 <table frame="all" xml:id="table.cxx17_features">
  42 <title>C++ 2017 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</entry>
  55     </row>
  56   </thead>
  57
  58   <tbody>
  59
  60     <row>
  61       <entry>
  62         <code>constexpr std::hardware_{constructive,destructive}_interference_size</code>
  63       </entry>
  64       <entry>
  65         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0154r1.html">
  66         P0154R1
  67         </link>
  68       </entry>
  69       <entry align="center"> 12.1 </entry>
  70       <entry> <code>__cpp_lib_hardware_interference_size >= 201603</code> </entry>
  71     </row>
  72
  73     <row>
  74       <entry> Core Issue 1776: Replacement of class objects containing reference members</entry>
  75       <entry>
  76         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0137r1.html">
  77         P0137R1
  78         </link>
  79       </entry>
  80       <entry align="center"> 7.1 </entry>
  81       <entry> <code>__cpp_lib_launder >= 201606</code> </entry>
  82     </row>
  83
  84     <row>
  85       <entry>Wording for <code>std::uncaught_exceptions</code></entry>
  86       <entry>
  87         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/JTC1/sc22/WG21/docs/papers/2014/n4259.pdf">
  88           N4259
  89         </link>
  90       </entry>
  91       <entry align="center">6.1</entry>
  92       <entry><code>__cpp_lib_uncaught_exceptions >= 201411</code></entry>
  93     </row>
  94
  95     <row>
  96       <entry> C++17 should refer to C11 instead of C99 </entry>
  97       <entry>
  98         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0063r3.html">
  99         P0063R3
 100         </link>
 101       </entry>
 102       <entry align="center"> 9.1 </entry>
 103       <entry/>
 104     </row>
 105
 106     <row>
 107       <entry> Variant: a type-safe union for C++17 </entry>
 108       <entry>
 109         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0088r3.html">
 110         P0088R3
 111         </link>
 112       </entry>
 113       <entry align="center"> 7.1 </entry>
 114       <entry> <code>__has_include(&lt;variant&gt;)</code>,
 115               <code>__cpp_lib_variant >= 201603</code>
 116               (since 7.3, see Note 1)
 117       </entry>
 118     </row>
 119
 120     <row>
 121       <entry> Library Fundamentals V1 TS Components: <code>optional</code> </entry>
 122       <entry>
 123         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 124         P0220R1
 125         </link>
 126       </entry>
 127       <entry align="center"> 7.1 </entry>
 128       <entry> <code>__has_include(&lt;optional&gt;)</code>,
 129               <code>__cpp_lib_optional >= 201603</code>
 130               (since 7.3, see Note 1)
 131       </entry>
 132     </row>
 133
 134     <row>
 135       <entry> Library Fundamentals V1 TS Components: <code>any</code> </entry>
 136       <entry>
 137         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 138         P0220R1
 139         </link>
 140       </entry>
 141       <entry align="center"> 7.1 </entry>
 142       <entry> <code>__has_include(&lt;any&gt;)</code>,
 143               <code>__cpp_lib_any >= 201603</code>
 144               (since 7.3, see Note 1)
 145       </entry>
 146     </row>
 147
 148     <row>
 149       <entry> Library Fundamentals V1 TS Components: <code>string_view</code> </entry>
 150       <entry>
 151         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 152         P0220R1
 153         </link>
 154       </entry>
 155       <entry align="center"> 7.1 </entry>
 156       <entry> <code>__has_include(&lt;string_view&gt;)</code>,
 157               <code>__cpp_lib_string_view >= 201603</code>
 158               (since 7.3, see Note 1)
 159       </entry>
 160     </row>
 161
 162     <row>
 163       <entry> Library Fundamentals V1 TS Components: <code>memory_resource</code> </entry>
 164       <entry>
 165         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 166         P0220R1
 167         </link>
 168       </entry>
 169       <entry align="center"> 9.1 </entry>
 170       <entry> <code>__has_include(&lt;memory_resource&gt;)</code>,
 171               <code>__cpp_lib_memory_resource >= 201603</code>
 172       </entry>
 173     </row>
 174
 175     <row>
 176       <entry> Library Fundamentals V1 TS Components: <code>apply</code> </entry>
 177       <entry>
 178         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 179         P0220R1
 180         </link>
 181       </entry>
 182       <entry align="center"> 7.1 </entry>
 183       <entry> <code>__cpp_lib_apply >= 201603</code> </entry>
 184     </row>
 185
 186     <row>
 187       <entry> Library Fundamentals V1 TS Components: <code>shared_ptr&lt;T[]&gt;</code> </entry>
 188       <entry>
 189         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 190         P0220R1
 191         </link>
 192       </entry>
 193       <entry align="center"> 7.1 </entry>
 194       <entry> <code>__cpp_lib_shared_ptr_arrays >= 201603</code> </entry>
 195     </row>
 196
 197     <row>
 198       <entry> Library Fundamentals V1 TS Components: Searchers </entry>
 199       <entry>
 200         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 201         P0220R1
 202         </link>
 203       </entry>
 204       <entry align="center"> 7.1 </entry>
 205       <entry> <code>__cpp_lib_boyer_moore_searcher >= 201603</code> </entry>
 206     </row>
 207
 208     <row>
 209       <entry> Library Fundamentals V1 TS Components: Sampling </entry>
 210       <entry>
 211         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 212         P0220R1
 213         </link>
 214       </entry>
 215       <entry align="center"> 7.1 </entry>
 216       <entry> <code>__cpp_lib_sample >= 201603</code> </entry>
 217     </row>
 218
 219     <row>
 220       <entry> Constant View: A proposal for a <code>std::as_const</code> helper function template       </entry>
 221       <entry>
 222         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="">
 223         P0007R1
 224         </link>
 225       </entry>
 226       <entry align="center"> 7.1 </entry>
 227       <entry><code> __cpp_lib_as_const >= 201510 </code></entry>
 228     </row>
 229
 230     <row>
 231       <entry> Improving pair and tuple </entry>
 232       <entry>
 233         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4387">
 234         N4387
 235         </link>
 236       </entry>
 237       <entry align="center"> 6.1 </entry>
 238       <entry> N/A </entry>
 239     </row>
 240
 241     <row>
 242       <entry> <code>make_from_tuple</code>: apply for construction </entry>
 243       <entry>
 244         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0209r2.pdf">
 245         P0209R2
 246         </link>
 247       </entry>
 248       <entry align="center"> 7.1 </entry>
 249       <entry><code> __cpp_lib_make_from_tuple >= 201606 </code></entry>
 250     </row>
 251
 252     <row>
 253       <?dbhtml bgcolor="#C8B0B0" ?>
 254       <entry>
 255         Removing <code>auto_ptr</code>, <code>random_shuffle()</code>,
 256         And Old <code>&lt;functional&gt;</code> Stuff
 257       </entry>
 258       <entry>
 259         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4190.htm">
 260           N4190
 261         </link>
 262       </entry>
 263       <entry align="center">No (kept for backwards compatibility)</entry>
 264       <entry/>
 265     </row>
 266
 267     <row>
 268       <entry> Deprecating Vestigial Library Parts in C++17 </entry>
 269       <entry>
 270         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0174r2.html">
 271         P0174R2
 272         </link>
 273       </entry>
 274       <entry align="center"> 12.1 </entry>
 275       <entry/>
 276     </row>
 277
 278     <row>
 279       <entry> Making <code>std::owner_less</code> more flexible </entry>
 280       <entry>
 281         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0074r0.html">
 282         P0074R0
 283         </link>
 284       </entry>
 285       <entry align="center"> 7.1 </entry>
 286       <entry><code> __cpp_lib_transparent_operators >= 201510 </code></entry>
 287     </row>
 288
 289     <row>
 290       <entry> <code>std::addressof</code> should be constexpr </entry>
 291       <entry>
 292         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0304r0.html#2296">
 293         LWG2296
 294         </link>
 295       </entry>
 296       <entry align="center"> 7.1 </entry>
 297       <entry><code> __cpp_lib_addressof_constexpr >= 201603 </code></entry>
 298     </row>
 299
 300     <row>
 301       <entry> Safe conversions in <code>unique_ptr&lt;T[]&gt;</code> </entry>
 302       <entry>
 303         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4089.pdf">
 304         N4089
 305         </link>
 306       </entry>
 307       <entry align="center"> 6 </entry>
 308       <entry/>
 309     </row>
 310
 311     <row>
 312       <entry> LWG 2228: Missing SFINAE rule in unique_ptr templated assignment </entry>
 313       <entry>
 314         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4366.html">
 315           N4366
 316         </link>
 317       </entry>
 318       <entry align="center"> 6 </entry>
 319       <entry/>
 320     </row>
 321
 322     <row>
 323       <entry> Re-enabling <code>shared_from_this</code></entry>
 324       <entry>
 325         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0033r1.html">
 326         P0033R1
 327         </link>
 328       </entry>
 329       <entry align="center"> 7.1 </entry>
 330       <entry><code>__cpp_lib_enable_shared_from_this >= 201603</code></entry>
 331     </row>
 332
 333     <row>
 334       <entry> A proposal to add <code>invoke</code> function template </entry>
 335       <entry>
 336         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4169.html">
 337         N4169
 338         </link>
 339       </entry>
 340       <entry align="center"> 6.1 </entry>
 341       <entry><code> __cpp_lib_invoke >= 201411 </code></entry>
 342     </row>
 343
 344     <row>
 345       <entry>TriviallyCopyable <code>reference_wrapper</code> </entry>
 346       <entry>
 347         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4277.html">
 348           N4277
 349         </link>
 350       </entry>
 351       <entry align="center"> 5.1 </entry>
 352       <entry/>
 353     </row>
 354
 355     <row>
 356       <entry> Adopt <code>not_fn</code> from Library Fundamentals 2 for C++17 </entry>
 357       <entry>
 358         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0005r4.html">
 359         P0005R4
 360         </link>
 361       </entry>
 362       <entry align="center"> 7.1 </entry>
 363       <entry><code>__cpp_lib_not_fn >= 201603</code></entry>
 364     </row>
 365
 366     <row>
 367       <entry> Fixes for <code>not_fn</code> </entry>
 368       <entry>
 369         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0358r1.html">
 370         P0358R1
 371         </link>
 372       </entry>
 373       <entry align="center"> 7.1 </entry>
 374       <entry/>
 375     </row>
 376
 377     <row>
 378       <entry> Fixing a design mistake in the searchers interface in Library Fundamentals </entry>
 379       <entry>
 380         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0253r1.pdf">
 381         P0253R1
 382         </link>
 383       </entry>
 384       <entry align="center"> 7.1 </entry>
 385       <entry/>
 386     </row>
 387
 388     <row>
 389       <entry> Extending memory management tools </entry>
 390       <entry>
 391         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0040r3.html">
 392         P0040R3
 393         </link>
 394       </entry>
 395       <entry align="center"> 7.1 </entry>
 396       <entry><code>__cpp_lib_raw_memory_algorithms &gt;= 201606L</code></entry>
 397     </row>
 398
 399     <row>
 400       <entry> <code>shared_ptr::weak_type</code></entry>
 401       <entry>
 402         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0163r0.html">
 403         P0163R0
 404         </link>
 405       </entry>
 406       <entry align="center"> 7.1 </entry>
 407       <entry><code> __cpp_lib_shared_ptr_weak_type >= 201606</code></entry>
 408     </row>
 409
 410     <row>
 411       <entry>Transformation Trait Alias <code>void_t</code></entry>
 412       <entry>
 413         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/JTC1/sc22/WG21/docs/papers/2014/n3911.pdf">
 414           N3911
 415         </link>
 416       </entry>
 417       <entry align="center">6.1</entry>
 418       <entry><code> __cpp_lib_void_t >= 201411</code></entry>
 419     </row>
 420
 421     <row>
 422       <entry> Wording for <code>bool_constant</code>, revision 1 </entry>
 423       <entry>
 424         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4389.html">
 425           N4389
 426         </link>
 427       </entry>
 428       <entry align="center">6.1</entry>
 429       <entry><code> __cpp_lib_bool_constant >= 201505</code></entry>
 430     </row>
 431
 432     <row>
 433       <entry> Adopt Type Traits Variable Templates from Library Fundamentals TS for C++17</entry>
 434       <entry>
 435         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0006r0.html">
 436         P0006R0
 437         </link>
 438       </entry>
 439       <entry align="center"> 7.1 </entry>
 440       <entry><code> __cpp_lib_type_trait_variable_templates >= 201510 </code></entry>
 441     </row>
 442
 443     <row>
 444       <entry> Logical Operator Type Traits</entry>
 445       <entry>
 446         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0013r1.html">
 447         P0013R1
 448         </link>
 449       </entry>
 450       <entry align="center"> 6.1 </entry>
 451       <entry><code> __cpp_lib_logical_traits >= 201510 </code></entry>
 452     </row>
 453
 454     <row>
 455       <entry> Adding [nothrow-]swappable traits </entry>
 456       <entry>
 457         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0185r1.html">
 458         P0185R1
 459         </link>
 460       </entry>
 461       <entry align="center"> 7.1 (<code>__is_swappable</code> available since 6.1)</entry>
 462       <entry><code> __cpp_lib_is_swappable >= 201603 </code></entry>
 463     </row>
 464
 465     <row>
 466       <entry> <code>is_callable</code>, the missing INVOKE related trait</entry>
 467       <entry>
 468         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0077r2.html">
 469         P0077R2
 470         </link>
 471       </entry>
 472       <entry align="center"> 7.1 </entry>
 473       <entry><code> __cpp_lib_is_invocable >= 201703 </code></entry>
 474     </row>
 475
 476     <row>
 477       <entry> has_unique_object_representations </entry>
 478       <entry>
 479         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0258r2.html">
 480         P0258R2
 481         </link>
 482       </entry>
 483       <entry align="center"> 7.1 </entry>
 484       <entry><code> __cpp_lib_has_unique_object_representations >= 201606 </code></entry>
 485     </row>
 486
 487     <row>
 488       <entry> Polishing <code>&lt;chrono&gt;</code> </entry>
 489       <entry>
 490         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0092r1.html">
 491         P0092R1
 492         </link>
 493       </entry>
 494       <entry align="center"> 7.1 </entry>
 495       <entry><code> __cpp_lib_chrono >= 201510 </code></entry>
 496     </row>
 497
 498     <row>
 499       <entry> Adding more constexpr to <code>&lt;chrono&gt;</code> </entry>
 500       <entry>
 501         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0505r0.html">
 502         P0505R0
 503         </link>
 504       </entry>
 505       <entry align="center"> 7.1 </entry>
 506       <entry><code> __cpp_lib_chrono >= 201611 </code>
 507              (since 7.3, see Note 2)
 508       </entry>
 509     </row>
 510
 511     <row>
 512       <entry> Constexpr for <code>std::char_traits</code> </entry>
 513       <entry>
 514         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0426r1.html">
 515         P0426R1
 516         </link>
 517       </entry>
 518       <entry align="center"> 8.1 </entry>
 519       <entry><code> __cpp_lib_constexpr_string >= 201611 </code></entry>
 520     </row>
 521
 522     <row>
 523       <entry> Integrating <code>std::string_view</code> and <code>std::string</code> </entry>
 524       <entry>
 525         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0254r2.pdf">
 526         P0254R2
 527         </link>
 528       </entry>
 529       <entry align="center"> 7.1 </entry>
 530       <entry><code> </code></entry>
 531     </row>
 532
 533     <row>
 534       <entry> Give 'std::string' a non-const '.data()' member function </entry>
 535       <entry>
 536         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0272r1.html">
 537         P0272R1
 538         </link>
 539       </entry>
 540       <entry align="center"> 7.1 </entry>
 541       <entry><code> </code></entry>
 542     </row>
 543
 544     <row>
 545       <entry>Cleaning-up noexcept in the Library</entry>
 546       <entry>
 547         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4258.pdf">
 548           N4258
 549         </link>
 550       </entry>
 551       <entry align="center">6.1</entry>
 552       <entry><code> __cpp_lib_allocator_traits_is_always_equal >= 201411 </code></entry>
 553     </row>
 554
 555     <row>
 556       <entry>Contiguous Iterators </entry>
 557       <entry>
 558         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4284.html">
 559           N4284
 560         </link>
 561       </entry>
 562       <entry align="center">N/A</entry>
 563       <entry/>
 564     </row>
 565
 566     <row>
 567       <entry> Minimal incomplete type support for standard containers </entry>
 568       <entry>
 569         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4510.html">
 570         N4510
 571         </link>
 572       </entry>
 573       <entry align="center"> 3.0 </entry>
 574       <entry><code> __cpp_lib_incomplete_container_elements >= 201505 </code>
 575              (since 6.2, see Note 2)
 576       </entry>
 577     </row>
 578
 579     <row>
 580       <entry> Emplace return type </entry>
 581       <entry>
 582         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0084r2.pdf">
 583         P0084R2
 584         </link>
 585       </entry>
 586       <entry align="center"> 7.1 </entry>
 587       <entry/>
 588     </row>
 589
 590     <row>
 591       <entry>Improved insertion interface for unique-key maps</entry>
 592       <entry>
 593         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4279.html">
 594           N4279
 595         </link>
 596       </entry>
 597       <entry align="center"> 6.1 </entry>
 598       <entry><code> __cpp_lib_map_try_emplace >= 201411</code>,
 599              <code> __cpp_lib_unordered_map_try_emplace >= 201411</code>
 600       </entry>
 601     </row>
 602
 603     <row>
 604       <entry> Splicing Maps and Sets </entry>
 605       <entry>
 606         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0083r3.pdf">
 607         P0083R3
 608         </link>
 609       </entry>
 610       <entry align="center"> 7.1 </entry>
 611       <entry><code> __cpp_lib_node_extract >= 201606 </code></entry>
 612     </row>
 613
 614     <row>
 615       <entry>Non-member <code>size()</code> and more</entry>
 616       <entry>
 617         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4280.pdf">
 618           N4280
 619         </link>
 620       </entry>
 621       <entry align="center"> 6.1 </entry>
 622       <entry><code> __cpp_lib_nonmember_container_access >= 201411 </code></entry>
 623     </row>
 624
 625     <row>
 626       <entry> A Proposal to Add Constexpr Modifiers to <code>reverse_iterator</code>, <code>move_iterator</code>, <code>array</code> and Range Access </entry>
 627       <entry>
 628         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0031r0.html">
 629         P0031R0
 630         </link>
 631       </entry>
 632       <entry align="center"> 7.1 </entry>
 633       <entry><code> __cpp_lib_array_constexpr >= 201603 </code></entry>
 634     </row>
 635
 636     <row>
 637       <?dbhtml bgcolor="#B0B0B0" ?>
 638       <entry> The Parallelism TS Should be Standardized  </entry>
 639       <entry>
 640         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0024r2.html">
 641         P0024R2
 642         </link>
 643       </entry>
 644       <entry align="center"> 9.1 </entry>
 645       <entry><code> __has_include(&lt;execution&gt;)</code>,
 646              <code> __cpp_lib_execution >= 201603 </code>,
 647              <code> __cpp_lib_parallel_algorithm >= 201603 </code>
 648              (requires linking with <code>-ltbb</code>, see Note 3)
 649       </entry>
 650     </row>
 651
 652     <row>
 653       <entry> An algorithm to "clamp" a value between a pair of boundary values </entry>
 654       <entry>
 655         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0025r0.html">
 656         P0025R0
 657         </link>
 658       </entry>
 659       <entry align="center"> 7.1 </entry>
 660       <entry><code> __cpp_lib_clamp >= 201603 </code></entry>
 661     </row>
 662
 663     <row>
 664       <entry> Adopt Selected Library Fundamentals V2 Components for C++17 </entry>
 665       <entry>
 666         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0295r0.pdf">
 667         P0295R0
 668         </link>
 669       </entry>
 670       <entry align="center"> 7.1 </entry>
 671       <entry><code> __cpp_lib_gcd_lcm >= 201606 </code></entry>
 672     </row>
 673
 674     <row>
 675       <entry> Proposal to Introduce a 3-Argument Overload to <code>std::hypot</code> </entry>
 676       <entry>
 677         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0030r1.pdf">
 678         P0030R1
 679         </link>
 680       </entry>
 681       <entry align="center"> 7.1 </entry>
 682       <entry><code> __cpp_lib_hypot >= 201603 </code></entry>
 683     </row>
 684
 685     <row>
 686       <entry> Mathematical Special Functions for C++17 </entry>
 687       <entry>
 688         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0226r1.pdf">
 689         P0226R1
 690         </link>
 691       </entry>
 692       <entry align="center"> 7.1 </entry>
 693       <entry><code> __cpp_lib_math_special_functions >= 201603 </code>
 694              (see Note 4)
 695       </entry>
 696     </row>
 697
 698     <row>
 699       <entry>Adopt the File System TS for C++17  </entry>
 700       <entry>
 701         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0218r1.html">
 702         P0218R1
 703         </link>
 704       </entry>
 705       <entry align="center"> 8.1 </entry>
 706       <entry><code> __has_include(&lt;filesystem&gt;)</code>,
 707              <code> __cpp_lib_filesystem >= 201603 </code>
 708              (GCC 8.x requires linking with <code>-lstdc++fs</code>)
 709       </entry>
 710     </row>
 711
 712     <row>
 713       <entry> Relative Paths for Filesystem</entry>
 714       <entry>
 715         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0219r1.html">
 716         P0219R1
 717         </link>
 718       </entry>
 719       <entry align="center"> 8.1 </entry>
 720       <entry><code> __cpp_lib_filesystem >= 201606 </code></entry>
 721     </row>
 722
 723     <row>
 724       <entry> Adapting string_view by filesystem paths </entry>
 725       <entry>
 726         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0392r0.pdf">
 727         P0392R0
 728         </link>
 729       </entry>
 730       <entry align="center"> 8.1 </entry>
 731       <entry><code> __cpp_lib_filesystem >= 201606 </code></entry>
 732     </row>
 733
 734     <row>
 735       <entry> Directory Entry Caching for Filesystem </entry>
 736       <entry>
 737        <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0317r1.html">
 738        P0317R1
 739        </link>
 740       </entry>
 741       <entry align="center"> 8.1 </entry>
 742       <entry><code> __cpp_lib_filesystem >= 201703 </code></entry>
 743      </row>
 744
 745     <row>
 746       <entry> constexpr <code>atomic&lt;T&gt;::is_always_lock_free</code>        </entry>
 747       <entry>
 748         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0152r1.html">
 749         P0152R1
 750         </link>
 751       </entry>
 752       <entry align="center"> 7.1 </entry>
 753       <entry><code> __cpp_lib_atomic_is_always_lock_free >= 201603 </code></entry>
 754     </row>
 755
 756     <row>
 757       <entry>A proposal to add <code>shared_mutex</code> (untimed) (Revision 4)</entry>
 758       <entry>
 759         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4508.html">
 760           N4508
 761         </link>
 762       </entry>
 763       <entry align="center"> 6.1 </entry>
 764       <entry><code> __cpp_lib_shared_mutex >= 201505 </code></entry>
 765     </row>
 766
 767     <row>
 768       <entry> Variadic <code>lock_guard</code> (Rev. 5) </entry>
 769       <entry>
 770         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0156r2.html">
 771         P0156R2
 772         </link>
 773       </entry>
 774       <entry align="center"> 7.1 </entry>
 775       <entry><code> __cpp_lib_scoped_lock >= 201703 </code></entry>
 776     </row>
 777
 778     <row>
 779       <entry> A byte type definition </entry>
 780       <entry>
 781         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0298r3.pdf">
 782         P0298R3
 783         </link>
 784       </entry>
 785       <entry align="center"> 7.1 </entry>
 786       <entry><code> __cpp_lib_byte >= 201603 </code> (since 7.3, see Note 2)
 787       </entry>
 788     </row>
 789
 790     <row>
 791       <entry> Elementary string conversions </entry>
 792       <entry>
 793         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0067r5.html">
 794         P0067R5
 795         </link>
 796       </entry>
 797       <entry align="center"> 11.1 (integral types supported since 8.1) </entry>
 798       <entry><code> __has_include(&lt;charconv&gt;)</code>,
 799              <code> __cpp_lib_to_chars >= 201611 </code></entry>
 800     </row>
 801
 802     <row>
 803       <entry> Homogeneous interface for variant, any and optional </entry>
 804       <entry>
 805         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0032r3.pdf">
 806         P0032R3
 807         </link>
 808       </entry>
 809       <entry align="center"> 7.1  </entry>
 810       <entry>
 811              <code> __cpp_lib_any >= 201606 </code>,
 812              <code> __cpp_lib_optional >= 201606 </code>,
 813              <code> __cpp_lib_variant >= 201606 </code>
 814       </entry>
 815     </row>
 816
 817     <row>
 818       <entry> Making Optional Greater Equal Again </entry>
 819       <entry>
 820         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0307r2.pdf">
 821         P0307R2
 822         </link>
 823       </entry>
 824       <entry align="center"> 7.1  </entry>
 825       <entry> <code> __cpp_lib_optional >= 201606 </code> </entry>
 826     </row>
 827
 828   </tbody>
 829 </tgroup>
 830 </table>
 831
 832 <para>
 833 Note 1: This feature is supported in GCC 7.1 and 7.2 but before GCC 7.3 the
 834 <code>__cpp_lib</code> macro is not defined, and compilation will fail if the
 835 header is included without using <option>-std</option> to enable C++17 support.
 836 </para>
 837
 838 <para>
 839 Note 2: This feature is supported in older releases but the
 840 <code>__cpp_lib</code> macro is not defined to the right value
 841 (or not defined at all) until the version shown in parentheses.
 842 </para>
 843
 844 <para>
 845 Note 3: The Parallel Algorithms have an external dependency on Intel TBB 2018
 846 or later. If the <filename class="headerfile">&lt;execution&gt;</filename>
 847 header is included then <code>-ltbb</code> must be used to link to TBB.
 848 </para>
 849
 850 <para>
 851 Note 4: The mathematical special functions are enabled in C++17 mode from
 852 GCC 7.1 onwards. For GCC 6.x or for C++11/C++14 define
 853 <code>__STDCPP_WANT_MATH_SPEC_FUNCS__</code> to a non-zero value
 854 and test for <code>__STDCPP_MATH_SPEC_FUNCS__ >= 201003L</code>.
 855 </para>
 856
 857
 858
 859 <para>
 860 The following status table is based on the table of contents of
 861 ISO/IEC 14882:2017.
 862 Some subclauses are not shown in the table where the content is unchanged
 863 since C++14 and the implementation is complete.
 864 </para>
 865
 866 <table frame="all" xml:id="table.cxx17_status">
 867 <title>C++ 2017 Implementation Status</title>
 868
 869 <tgroup cols="4" align="left" colsep="0" rowsep="1">
 870 <colspec colname="c1"/>
 871 <colspec colname="c2"/>
 872 <colspec colname="c3"/>
 873 <colspec colname="c4"/>
 874   <thead>
 875     <row>
 876       <entry>Section</entry>
 877       <entry>Description</entry>
 878       <entry>Status</entry>
 879       <entry>Comments</entry>
 880     </row>
 881   </thead>
 882
 883   <tbody>
 884
 885     <row>
 886       <entry>
 887         <emphasis>21</emphasis>
 888       </entry>
 889       <entry namest="c2" nameend="c4" align="left">
 890         <emphasis>Language support</emphasis>
 891       </entry>
 892     </row>
 893
 894     <row>
 895       <entry>21.1</entry>
 896       <entry>General</entry>
 897       <entry/>
 898       <entry/>
 899     </row>
 900     <row>
 901       <entry>21.2</entry>
 902       <entry>Common definitions</entry>
 903       <entry/>
 904       <entry/>
 905     </row>
 906     <row>
 907       <entry>21.3</entry>
 908       <entry>Implementation properties</entry>
 909       <entry/>
 910       <entry/>
 911     </row>
 912     <row>
 913       <entry>21.3.1</entry>
 914       <entry>General</entry>
 915       <entry/>
 916       <entry/>
 917     </row>
 918     <row>
 919       <entry>21.3.2</entry>
 920       <entry>Header <code>&lt;limits&gt;</code> synopsis</entry>
 921       <entry/>
 922       <entry/>
 923     </row>
 924     <row>
 925       <entry>21.3.3</entry>
 926       <entry>Floating-point type properties</entry>
 927       <entry/>
 928       <entry/>
 929     </row>
 930     <row>
 931       <?dbhtml bgcolor="#C8B0B0" ?>
 932       <entry>21.3.3.1</entry>
 933       <entry><code>float_round_style</code></entry>
 934       <entry>N</entry>
 935       <entry/>
 936     </row>
 937     <row>
 938       <?dbhtml bgcolor="#C8B0B0" ?>
 939       <entry>21.3.3.2</entry>
 940       <entry><code>float_denorm_style</code></entry>
 941       <entry>N</entry>
 942       <entry/>
 943     </row>
 944     <row>
 945       <entry>21.3.4</entry>
 946       <entry>Class template <code>numeric_limits</code></entry>
 947       <entry>Y</entry>
 948       <entry/>
 949     </row>
 950     <row>
 951       <entry>21.3.5</entry>
 952       <entry>Header <code>&lt;climits&gt;</code> synopsis</entry>
 953       <entry>Y</entry>
 954       <entry/>
 955     </row>
 956     <row>
 957       <entry>21.3.6</entry>
 958       <entry>Header <code>&lt;cfloat&gt;</code> synopsis</entry>
 959       <entry>Y</entry>
 960       <entry/>
 961     </row>
 962     <row>
 963       <entry>21.4</entry>
 964       <entry>Integer types</entry>
 965       <entry/>
 966       <entry/>
 967     </row>
 968     <row>
 969       <entry>21.4.1</entry>
 970       <entry>Header <code>&lt;cstdint&gt;</code> synopsis</entry>
 971       <entry>Y</entry>
 972       <entry/>
 973     </row>
 974     <row>
 975       <?dbhtml bgcolor="#B0B0B0" ?>
 976       <entry>21.5</entry>
 977       <entry>Start and termination</entry>
 978       <entry>Partial</entry>
 979       <entry>C library dependency for quick_exit, at_quick_exit</entry>
 980     </row>
 981     <row>
 982       <entry>21.6</entry>
 983       <entry>Dynamic memory management</entry>
 984       <entry/>
 985       <entry/>
 986     </row>
 987     <row>
 988       <entry>21.6.1</entry>
 989       <entry>Header <code>&lt;new&gt;</code> synopsis</entry>
 990       <entry/>
 991       <entry/>
 992     </row>
 993     <row>
 994       <entry>21.6.2</entry>
 995       <entry>Storage allocation and deallocation</entry>
 996       <entry>Y</entry>
 997       <entry/>
 998     </row>
 999     <row>
1000       <entry>21.6.3</entry>
1001       <entry>Storage allocation errors</entry>
1002       <entry>Y</entry>
1003       <entry/>
1004     </row>
1005     <row>
1006       <entry>21.6.4</entry>
1007       <entry>Pointer optimization barrier</entry>
1008       <entry>Y</entry>
1009       <entry/>
1010     </row>
1011     <row>
1012       <entry>21.6.5</entry>
1013       <entry>Hardware interference size</entry>
1014       <entry>Y</entry>
1015       <entry/>
1016     </row>
1017     <row>
1018       <entry>21.7</entry>
1019       <entry>Type identification</entry>
1020       <entry>Y</entry>
1021       <entry/>
1022     </row>
1023     <row>
1024       <entry>21.8</entry>
1025       <entry>Exception handling</entry>
1026       <entry/>
1027       <entry/>
1028     </row>
1029     <row>
1030       <entry>21.8.1</entry>
1031       <entry>Header <code>&lt;exception&gt;</code> synopsis</entry>
1032       <entry/>
1033       <entry/>
1034     </row>
1035     <row>
1036       <entry>21.8.2</entry>
1037       <entry>Class exception</entry>
1038       <entry>Y</entry>
1039       <entry/>
1040     </row>
1041     <row>
1042       <entry>21.8.3</entry>
1043       <entry>Class bad_exception</entry>
1044       <entry>Y</entry>
1045       <entry/>
1046     </row>
1047     <row>
1048       <entry>21.8.4</entry>
1049       <entry>Abnormal termination</entry>
1050       <entry>Y</entry>
1051       <entry/>
1052     </row>
1053     <row>
1054       <entry>21.8.5</entry>
1055       <entry><code>uncaught_exceptions</code></entry>
1056       <entry>Y</entry>
1057       <entry/>
1058     </row>
1059     <row>
1060       <entry>21.8.6</entry>
1061       <entry>Exception Propagation</entry>
1062       <entry>Y</entry>
1063       <entry/>
1064     </row>
1065     <row>
1066       <entry>21.8.7</entry>
1067       <entry><code>nested_exception</code></entry>
1068       <entry>Y</entry>
1069       <entry/>
1070     </row>
1071     <row>
1072       <entry>21.9</entry>
1073       <entry>Initializer lists</entry>
1074       <entry>Y</entry>
1075       <entry/>
1076     </row>
1077     <row>
1078       <entry>21.10</entry>
1079       <entry>Other runtime support</entry>
1080       <entry>Y</entry>
1081       <entry/>
1082     </row>
1083     <row>
1084       <entry>
1085         <emphasis>22</emphasis>
1086       </entry>
1087       <entry namest="c2" nameend="c4" align="left">
1088         <emphasis>Diagnostics</emphasis>
1089       </entry>
1090     </row>
1091     <row>
1092       <entry>22.1</entry>
1093       <entry>General</entry>
1094       <entry/>
1095       <entry/>
1096     </row>
1097     <row>
1098       <entry>22.2</entry>
1099       <entry>Exception classes</entry>
1100       <entry>Y</entry>
1101       <entry/>
1102     </row>
1103     <row>
1104       <entry>22.3</entry>
1105       <entry>Assertions</entry>
1106       <entry>Y</entry>
1107       <entry/>
1108     </row>
1109     <row>
1110       <entry>22.4</entry>
1111       <entry>Error numbers</entry>
1112       <entry>Y</entry>
1113       <entry/>
1114     </row>
1115     <row>
1116       <entry>22.5</entry>
1117       <entry>System error support</entry>
1118       <entry/>
1119       <entry/>
1120     </row>
1121     <row>
1122       <entry>
1123         <emphasis>23</emphasis>
1124       </entry>
1125       <entry namest="c2" nameend="c4" align="left">
1126         <emphasis>General utilities</emphasis>
1127       </entry>
1128     </row>
1129     <row>
1130       <entry>23.1</entry>
1131       <entry>General</entry>
1132       <entry/>
1133       <entry/>
1134     </row>
1135     <row>
1136       <entry>23.2</entry>
1137       <entry>Utility components</entry>
1138       <entry/>
1139       <entry/>
1140     </row>
1141     <row>
1142       <entry>23.2.1</entry>
1143       <entry>Header <code>&lt;utility&gt;</code> synopsis</entry>
1144       <entry/>
1145       <entry/>
1146     </row>
1147     <row>
1148       <entry>23.2.2</entry>
1149       <entry>Operators</entry>
1150       <entry>Y</entry>
1151       <entry/>
1152     </row>
1153     <row>
1154       <entry>23.2.3</entry>
1155       <entry><code>swap</code></entry>
1156       <entry>Y</entry>
1157       <entry/>
1158     </row>
1159     <row>
1160       <entry>23.2.4</entry>
1161       <entry><code>exchange</code></entry>
1162       <entry>Y</entry>
1163       <entry/>
1164     </row>
1165     <row>
1166       <entry>23.2.5</entry>
1167       <entry>Forward/move helpers</entry>
1168       <entry>Y</entry>
1169       <entry/>
1170     </row>
1171     <row>
1172       <entry>23.2.6</entry>
1173       <entry>Function template <code>as_const</code></entry>
1174       <entry>Y</entry>
1175       <entry/>
1176     </row>
1177     <row>
1178       <entry>23.2.7</entry>
1179       <entry>Function template <code>declval</code></entry>
1180       <entry>Y</entry>
1181       <entry/>
1182     </row>
1183     <row>
1184       <entry>23.2.8</entry>
1185       <entry>Primitive numeric output conversion</entry>
1186       <entry>Partial</entry>
1187       <entry/>
1188     </row>
1189     <row>
1190       <entry>23.2.9</entry>
1191       <entry>Primitive numeric input conversion</entry>
1192       <entry>Partial</entry>
1193       <entry/>
1194     </row>
1195     <row>
1196       <entry>23.3</entry>
1197       <entry>Compile-time integer sequences</entry>
1198       <entry/>
1199       <entry/>
1200     </row>
1201     <row>
1202       <entry>23.4</entry>
1203       <entry>Pairs</entry>
1204       <entry>Y</entry>
1205       <entry/>
1206     </row>
1207     <row>
1208       <entry>23.5</entry>
1209       <entry>Tuples</entry>
1210       <entry>Y</entry>
1211       <entry/>
1212     </row>
1213     <row>
1214       <entry>23.6</entry>
1215       <entry>Optional objects</entry>
1216       <entry>Y</entry>
1217       <entry/>
1218     </row>
1219     <row>
1220       <entry>23.7</entry>
1221       <entry>Variants</entry>
1222       <entry>Y</entry>
1223       <entry/>
1224     </row>
1225     <row>
1226       <entry>23.8</entry>
1227       <entry>Storage for any type</entry>
1228       <entry>Y</entry>
1229       <entry/>
1230     </row>
1231     <row>
1232       <entry>23.9</entry>
1233       <entry>Bitsets</entry>
1234       <entry>Y</entry>
1235       <entry/>
1236     </row>
1237     <row>
1238       <entry>23.10</entry>
1239       <entry>Memory</entry>
1240       <entry>Y</entry>
1241       <entry/>
1242     </row>
1243                 <row>
1244       <entry>23.10.1</entry>
1245       <entry>In general</entry>
1246       <entry/>
1247       <entry/>
1248     </row>
1249                 <row>
1250       <entry>23.10.2</entry>
1251       <entry>Header <code>&lt;memory&gt;</code> synopsis</entry>
1252       <entry>Y</entry>
1253       <entry/>
1254     </row>
1255                 <row>
1256       <entry>23.10.3</entry>
1257       <entry>Pointer traits</entry>
1258       <entry>Y</entry>
1259       <entry/>
1260     </row>
1261                 <row>
1262       <entry>23.10.4</entry>
1263       <entry>Pointer safety</entry>
1264       <entry>Y</entry>
1265       <entry/>
1266     </row>
1267                 <row>
1268       <entry>23.10.5</entry>
1269       <entry>Align</entry>
1270       <entry>Y</entry>
1271       <entry/>
1272     </row>
1273                 <row>
1274       <entry>23.10.6</entry>
1275       <entry>Allocator argument tag</entry>
1276       <entry>Y</entry>
1277       <entry/>
1278     </row>
1279                 <row>
1280       <entry>23.10.7</entry>
1281       <entry><code>uses_allocator</code></entry>
1282       <entry>Y</entry>
1283       <entry/>
1284     </row>
1285                 <row>
1286       <entry>23.10.8</entry>
1287       <entry>Allocator traits</entry>
1288       <entry>Y</entry>
1289       <entry/>
1290     </row>
1291                 <row>
1292       <entry>23.10.9</entry>
1293       <entry>The default allocator</entry>
1294       <entry>Y</entry>
1295       <entry/>
1296     </row>
1297                 <row>
1298       <entry>23.10.10</entry>
1299       <entry>Specialized algorithms</entry>
1300       <entry>Y</entry>
1301       <entry/>
1302     </row>
1303                 <row>
1304       <entry>23.10.11</entry>
1305       <entry>C library memory allocation</entry>
1306       <entry>Y</entry>
1307       <entry/>
1308     </row>
1309     <row>
1310       <entry>23.11</entry>
1311       <entry>Smart pointers</entry>
1312       <entry/>
1313       <entry/>
1314     </row>
1315     <row>
1316       <entry>23.11.1</entry>
1317       <entry>Class template <code>unique_ptr</code></entry>
1318       <entry>Y</entry>
1319       <entry/>
1320     </row>
1321     <row>
1322       <entry>23.11.2</entry>
1323       <entry>Shared-ownership pointers</entry>
1324       <entry>Y</entry>
1325       <entry/>
1326     </row>
1327     <row>
1328       <entry>23.12</entry>
1329       <entry>Memory resources</entry>
1330       <entry/>
1331       <entry/>
1332     </row>
1333     <row>
1334       <entry>23.12.1</entry>
1335       <entry>Header <code>&lt;memory_resource&gt;</code> synopsis</entry>
1336       <entry>Y</entry>
1337       <entry/>
1338     </row>
1339     <row>
1340       <entry>23.12.2</entry>
1341       <entry>Class <code>memory_resource</code></entry>
1342       <entry>Y</entry>
1343       <entry/>
1344     </row>
1345     <row>
1346       <entry>23.12.3</entry>
1347       <entry>Class template <code>polymorphic_allocator</code></entry>
1348       <entry>Y</entry>
1349       <entry/>
1350     </row>
1351     <row>
1352       <entry>23.12.4</entry>
1353       <entry>Access to program-wide <code>memory_resource</code> objects</entry>
1354       <entry>Y</entry>
1355       <entry/>
1356     </row>
1357     <row>
1358       <entry>23.12.5</entry>
1359       <entry>Pool resource classes</entry>
1360       <entry>Y</entry>
1361       <entry/>
1362     </row>
1363     <row>
1364       <entry>23.12.6</entry>
1365       <entry>Class <code>monotonic_buffer_resource</code></entry>
1366       <entry>Y</entry>
1367       <entry/>
1368     </row>
1369     <row>
1370       <entry>23.13</entry>
1371       <entry>Class template <code>scoped_allocator_adaptor</code></entry>
1372       <entry>Y</entry>
1373       <entry/>
1374     </row>
1375     <row>
1376       <entry>23.14</entry>
1377       <entry>Function objects</entry>
1378       <entry/>
1379       <entry/>
1380     </row>
1381     <row>
1382       <entry>23.14.1</entry>
1383       <entry>Header <code>&lt;functional&gt;</code> synopsis</entry>
1384       <entry/>
1385       <entry/>
1386     </row>
1387     <row>
1388       <entry>23.14.2</entry>
1389       <entry>Definitions</entry>
1390       <entry/>
1391       <entry/>
1392     </row>
1393     <row>
1394       <entry>23.14.3</entry>
1395       <entry>Requirements</entry>
1396       <entry/>
1397       <entry/>
1398     </row>
1399     <row>
1400       <entry>23.14.4</entry>
1401       <entry>Function template <code>invoke</code></entry>
1402       <entry>Y</entry>
1403       <entry/>
1404     </row>
1405     <row>
1406       <entry>23.14.5</entry>
1407       <entry>Class template <code>reference_wrapper</code></entry>
1408       <entry>Y</entry>
1409       <entry/>
1410     </row>
1411     <row>
1412       <entry>23.14.6</entry>
1413       <entry>Arithmetic operation</entry>
1414       <entry>Y</entry>
1415       <entry/>
1416     </row>
1417     <row>
1418       <entry>23.14.7</entry>
1419       <entry>Comparisons</entry>
1420       <entry>Y</entry>
1421       <entry/>
1422     </row>
1423     <row>
1424       <entry>23.14.8</entry>
1425       <entry>Logical operations</entry>
1426       <entry>Y</entry>
1427       <entry/>
1428     </row>
1429     <row>
1430       <entry>23.14.9</entry>
1431       <entry>Bitwise operations</entry>
1432       <entry>Y</entry>
1433       <entry/>
1434     </row>
1435     <row>
1436       <entry>23.14.10</entry>
1437       <entry>Function template <code>not_fn</code></entry>
1438       <entry>Y</entry>
1439       <entry/>
1440     </row>
1441     <row>
1442       <entry>23.14.11</entry>
1443       <entry>Function object binders</entry>
1444       <entry>Y</entry>
1445       <entry/>
1446     </row>
1447     <row>
1448       <entry>23.14.12</entry>
1449       <entry>Function template <code>mem_fn</code></entry>
1450       <entry>Y</entry>
1451       <entry/>
1452     </row>
1453     <row>
1454       <entry>23.14.13</entry>
1455       <entry>Polymorphic function wrappers</entry>
1456       <entry>Y</entry>
1457       <entry/>
1458     </row>
1459     <row>
1460       <entry>23.14.14</entry>
1461       <entry>Searchers</entry>
1462       <entry>Y</entry>
1463       <entry/>
1464     </row>
1465     <row>
1466       <entry>23.14.15</entry>
1467       <entry>Class template <code>hash</code></entry>
1468       <entry>Y</entry>
1469       <entry/>
1470     </row>
1471     <row>
1472       <entry>23.15</entry>
1473       <entry>Metaprogramming and type traits</entry>
1474       <entry/>
1475       <entry/>
1476     </row>
1477     <row>
1478       <entry>23.15.1</entry>
1479       <entry>Requirements</entry>
1480       <entry/>
1481       <entry/>
1482     </row>
1483     <row>
1484       <entry>23.15.2</entry>
1485       <entry>Header <code>&lt;type_traits&gt;</code> synopsis</entry>
1486       <entry>Y</entry>
1487       <entry/>
1488     </row>
1489     <row>
1490       <entry>23.15.3</entry>
1491       <entry>Helper classes</entry>
1492       <entry>Y</entry>
1493       <entry/>
1494     </row>
1495     <row>
1496       <entry>23.15.4</entry>
1497       <entry>Unary Type Traits</entry>
1498       <entry>Y</entry>
1499       <entry/>
1500     </row>
1501     <row>
1502       <entry>23.15.5</entry>
1503       <entry>Type property queries</entry>
1504       <entry>Y</entry>
1505       <entry/>
1506     </row>
1507     <row>
1508       <entry>23.15.6</entry>
1509       <entry>Relationships between types</entry>
1510       <entry>Y</entry>
1511       <entry/>
1512     </row>
1513     <row>
1514       <entry>23.15.7</entry>
1515       <entry>Transformations between types</entry>
1516       <entry>Y</entry>
1517       <entry/>
1518     </row>
1519     <row>
1520       <entry>23.15.8</entry>
1521       <entry>Logical operator traits</entry>
1522       <entry>Y</entry>
1523       <entry/>
1524     </row>
1525     <row>
1526       <entry>23.16</entry>
1527       <entry>Compile-time rational arithmetic</entry>
1528       <entry>Y</entry>
1529       <entry/>
1530     </row>
1531     <row>
1532       <entry>23.17.1</entry>
1533       <entry>In general</entry>
1534       <entry/>
1535       <entry/>
1536     </row>
1537     <row>
1538       <entry>23.17.2</entry>
1539       <entry>Header <code>&lt;chrono&gt;</code> synopsis</entry>
1540       <entry/>
1541       <entry/>
1542     </row>
1543     <row>
1544       <entry>23.17</entry>
1545       <entry>Time utilities</entry>
1546       <entry/>
1547       <entry/>
1548     </row>
1549     <row>
1550       <entry>23.17.3</entry>
1551       <entry>Clock requirements</entry>
1552       <entry>Y</entry>
1553       <entry/>
1554     </row>
1555     <row>
1556       <entry>23.17.4</entry>
1557       <entry>Time-related traits</entry>
1558       <entry>Y</entry>
1559       <entry/>
1560     </row>
1561     <row>
1562       <entry>23.17.5</entry>
1563       <entry>Class template <code>duration</code></entry>
1564       <entry>Y</entry>
1565       <entry/>
1566     </row>
1567     <row>
1568       <entry>23.17.6</entry>
1569       <entry>Class template <code>time_point</code></entry>
1570       <entry>Y</entry>
1571       <entry/>
1572     </row>
1573     <row>
1574       <entry>23.17.7</entry>
1575       <entry>Clocks</entry>
1576       <entry>Y</entry>
1577       <entry/>
1578     </row>
1579     <row>
1580       <entry>23.17.8</entry>
1581       <entry>Header <code>&lt;ctime&gt;</code> synopsis</entry>
1582       <entry>Y</entry>
1583       <entry/>
1584     </row>
1585     <row>
1586       <entry>23.18</entry>
1587       <entry>Class <code>type_index</code></entry>
1588       <entry>Y</entry>
1589       <entry/>
1590     </row>
1591     <row>
1592       <entry>23.19</entry>
1593       <entry>Execution policies</entry>
1594       <entry/>
1595       <entry/>
1596     </row>
1597     <row>
1598       <entry>23.19.1</entry>
1599       <entry>In general</entry>
1600       <entry/>
1601       <entry/>
1602     </row>
1603     <row>
1604       <entry>23.19.2</entry>
1605       <entry>Header <code>&lt;execution&gt;</code> synopsis</entry>
1606       <entry/>
1607       <entry/>
1608     </row>
1609     <row>
1610       <entry>23.19.3</entry>
1611       <entry>Execution policy type trait</entry>
1612       <entry>Y</entry>
1613       <entry/>
1614     </row>
1615     <row>
1616       <entry>23.19.4</entry>
1617       <entry>Sequenced execution policy</entry>
1618       <entry>Y</entry>
1619       <entry/>
1620     </row>
1621     <row>
1622       <entry>23.19.5</entry>
1623       <entry>Parallel execution policy</entry>
1624       <entry>Y</entry>
1625       <entry/>
1626     </row>
1627     <row>
1628       <entry>23.19.6</entry>
1629       <entry>Parallel and unsequenced execution policy</entry>
1630       <entry>Y</entry>
1631       <entry/>
1632     </row>
1633     <row>
1634       <entry>23.19.7</entry>
1635       <entry>Execution policy objects</entry>
1636       <entry>Y</entry>
1637       <entry/>
1638     </row>
1639     <row>
1640       <entry>
1641         <emphasis>24</emphasis>
1642       </entry>
1643       <entry namest="c2" nameend="c4" align="left">
1644         <emphasis>Strings</emphasis>
1645       </entry>
1646     </row>
1647     <row>
1648       <entry>24.1</entry>
1649       <entry>General</entry>
1650       <entry/>
1651       <entry/>
1652     </row>
1653     <row>
1654       <entry>24.2</entry>
1655       <entry>Character traits</entry>
1656       <entry>Y</entry>
1657       <entry/>
1658     </row>
1659     <row>
1660       <entry>24.3</entry>
1661       <entry>String classes</entry>
1662       <entry>Y</entry>
1663       <entry/>
1664     </row>
1665     <row>
1666       <entry>24.4</entry>
1667       <entry>String view classes</entry>
1668       <entry>Y</entry>
1669       <entry/>
1670     </row>
1671     <row>
1672       <entry>24.4.1</entry>
1673       <entry>Header <code>&lt;string_view&gt;</code> synopsis</entry>
1674       <entry>Y</entry>
1675       <entry/>
1676     </row>
1677     <row>
1678       <entry>24.4.2</entry>
1679       <entry>Class template <code>basic_string_view</code></entry>
1680       <entry>Y</entry>
1681       <entry/>
1682     </row>
1683     <row>
1684       <entry>24.4.3</entry>
1685       <entry>Non-member comparison functions</entry>
1686       <entry>Y</entry>
1687       <entry/>
1688     </row>
1689     <row>
1690       <entry>24.4.4</entry>
1691       <entry>Inserters and extractors</entry>
1692       <entry>Y</entry>
1693       <entry/>
1694     </row>
1695     <row>
1696       <entry>24.4.5</entry>
1697       <entry>Hash support</entry>
1698       <entry>Y</entry>
1699       <entry/>
1700     </row>
1701     <row>
1702       <entry>24.4.6</entry>
1703       <entry>Suffix for <code>basic_string_view</code> literals</entry>
1704       <entry>Y</entry>
1705       <entry/>
1706     </row>
1707     <row>
1708       <?dbhtml bgcolor="#B0B0B0" ?>
1709       <entry>24.5</entry>
1710       <entry>Null-terminated sequence utilities</entry>
1711       <entry>Partial</entry>
1712       <entry>C library dependency. </entry>
1713     </row>
1714     <row>
1715       <entry>
1716         <emphasis>25</emphasis>
1717       </entry>
1718       <entry namest="c2" nameend="c4" align="left">
1719         <emphasis>Localization</emphasis>
1720       </entry>
1721     </row>
1722     <row>
1723       <entry>25.1</entry>
1724       <entry>General</entry>
1725       <entry>Y</entry>
1726       <entry/>
1727     </row>
1728     <row>
1729       <entry>25.2</entry>
1730       <entry>Header <code>&lt;locale&gt;</code> synopsis</entry>
1731       <entry>Y</entry>
1732       <entry/>
1733     </row>
1734     <row>
1735       <entry>25.3</entry>
1736       <entry>Locales</entry>
1737       <entry>Y</entry>
1738       <entry/>
1739     </row>
1740     <row>
1741       <entry>25.4</entry>
1742       <entry>Standard <code>locale</code> categories</entry>
1743       <entry>Y</entry>
1744       <entry/>
1745     </row>
1746     <row>
1747       <entry>25.5</entry>
1748       <entry>C Library Locales</entry>
1749       <entry>Y</entry>
1750       <entry/>
1751     </row>
1752     <row>
1753       <entry>
1754         <emphasis>26</emphasis>
1755       </entry>
1756       <entry namest="c2" nameend="c4" align="left">
1757         <emphasis>Containers</emphasis>
1758       </entry>
1759     </row>
1760     <row>
1761       <entry>26.1</entry>
1762       <entry>General</entry>
1763       <entry/>
1764       <entry/>
1765     </row>
1766     <row>
1767       <entry>26.2</entry>
1768       <entry>Container requirements</entry>
1769       <entry>Y</entry>
1770       <entry/>
1771     </row>
1772     <row>
1773       <entry>26.3</entry>
1774       <entry>Sequence containers</entry>
1775       <entry>Y</entry>
1776       <entry/>
1777     </row>
1778     <row>
1779       <entry>26.4</entry>
1780       <entry>Associative containers</entry>
1781       <entry>Y</entry>
1782       <entry/>
1783     </row>
1784     <row>
1785       <entry>26.5</entry>
1786       <entry>Unordered associative containers</entry>
1787       <entry>Y</entry>
1788       <entry/>
1789     </row>
1790     <row>
1791       <entry>26.6</entry>
1792       <entry>Container adaptors</entry>
1793       <entry>Y</entry>
1794       <entry/>
1795     </row>
1796     <row>
1797       <entry>
1798         <emphasis>27</emphasis>
1799       </entry>
1800       <entry namest="c2" nameend="c4" align="left">
1801         <emphasis>Iterators</emphasis>
1802       </entry>
1803     </row>
1804     <row>
1805       <entry>27.1</entry>
1806       <entry>General</entry>
1807       <entry>Y</entry>
1808       <entry/>
1809     </row>
1810     <row>
1811       <entry>27.2</entry>
1812       <entry>Iterator requirements</entry>
1813       <entry>Y</entry>
1814       <entry/>
1815     </row>
1816     <row>
1817       <entry>27.3</entry>
1818       <entry>Header <code>&lt;iterator&gt;</code> synopsis</entry>
1819       <entry>Y</entry>
1820       <entry/>
1821     </row>
1822     <row>
1823       <entry>27.4</entry>
1824       <entry>Iterator primitives</entry>
1825       <entry>Y</entry>
1826       <entry/>
1827     </row>
1828     <row>
1829       <entry>27.5</entry>
1830       <entry>Iterator adaptors</entry>
1831       <entry>Y</entry>
1832       <entry/>
1833     </row>
1834     <row>
1835       <entry>27.6</entry>
1836       <entry>Stream iterators</entry>
1837       <entry>Y</entry>
1838       <entry/>
1839     </row>
1840     <row>
1841       <entry>27.7</entry>
1842       <entry>Range access</entry>
1843       <entry>Y</entry>
1844       <entry/>
1845     </row>
1846     <row>
1847       <entry>27.8</entry>
1848       <entry>Container access</entry>
1849       <entry>Y</entry>
1850       <entry/>
1851     </row>
1852     <row>
1853       <entry>
1854         <emphasis>28</emphasis>
1855       </entry>
1856       <entry namest="c2" nameend="c4" align="left">
1857         <emphasis>Algorithms</emphasis>
1858       </entry>
1859     </row>
1860     <row>
1861       <entry>28.1</entry>
1862       <entry>General</entry>
1863       <entry/>
1864       <entry/>
1865     </row>
1866     <row>
1867       <entry>28.2</entry>
1868       <entry>Header <code>&lt;algorithm&gt;</code> synopsis</entry>
1869       <entry/>
1870       <entry/>
1871     </row>
1872     <row>
1873       <entry>28.3</entry>
1874       <entry>Algorithms requirements</entry>
1875       <entry/>
1876       <entry/>
1877     </row>
1878     <row>
1879       <entry>28.4</entry>
1880       <entry>Parallel algorithms</entry>
1881       <entry/>
1882       <entry>Using <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://github.com/llvm/llvm-project/tree/main/pstl">PSTL</link></entry>
1883     </row>
1884     <row>
1885       <entry>28.5</entry>
1886       <entry>Non-modifying sequence operations</entry>
1887       <entry>Y</entry>
1888       <entry/>
1889     </row>
1890     <row>
1891       <entry>28.6</entry>
1892       <entry>Mutating sequence operations</entry>
1893       <entry>Y</entry>
1894       <entry/>
1895     </row>
1896     <row>
1897       <entry>28.7</entry>
1898       <entry>Sorting and related operations</entry>
1899       <entry>Y</entry>
1900       <entry/>
1901     </row>
1902     <row>
1903       <entry>28.8</entry>
1904       <entry>C library algorithms</entry>
1905       <entry>Y</entry>
1906       <entry/>
1907     </row>
1908     <row>
1909       <entry>
1910       <emphasis>29</emphasis>
1911       </entry>
1912       <entry namest="c2" nameend="c4" align="left">
1913         <emphasis>Numerics</emphasis>
1914       </entry>
1915     </row>
1916     <row>
1917       <entry>29.1</entry>
1918       <entry>General</entry>
1919       <entry/>
1920       <entry/>
1921     </row>
1922     <row>
1923       <entry>29.2</entry>
1924       <entry>Definitions</entry>
1925       <entry/>
1926       <entry/>
1927     </row>
1928     <row>
1929       <entry>29.3</entry>
1930       <entry>Numeric type requirements</entry>
1931       <entry>Y</entry>
1932       <entry/>
1933     </row>
1934     <row>
1935       <entry>29.4</entry>
1936       <entry>The floating-point environment</entry>
1937       <entry>Y</entry>
1938       <entry/>
1939     </row>
1940     <row>
1941       <entry>29.5</entry>
1942       <entry>Complex numbers</entry>
1943       <entry>Y</entry>
1944       <entry/>
1945     </row>
1946     <row>
1947       <entry>29.6</entry>
1948       <entry>Random number generation</entry>
1949       <entry>Y</entry>
1950       <entry/>
1951     </row>
1952     <row>
1953       <entry>29.7</entry>
1954       <entry>Numeric arrays</entry>
1955       <entry>Y</entry>
1956       <entry/>
1957     </row>
1958     <row>
1959       <entry>29.8</entry>
1960       <entry>Generalized numeric operations</entry>
1961       <entry/>
1962       <entry/>
1963     </row>
1964     <row>
1965       <entry>29.8.1</entry>
1966       <entry>Header <code>&lt;numeric&gt;</code> synopsis</entry>
1967       <entry/>
1968       <entry/>
1969     </row>
1970     <row>
1971       <entry>29.8.2</entry>
1972       <entry>Accumulate</entry>
1973       <entry>Y</entry>
1974       <entry/>
1975     </row>
1976     <row>
1977       <entry>29.8.3</entry>
1978       <entry>Reduce</entry>
1979       <entry>Y</entry>
1980       <entry/>
1981     </row>
1982     <row>
1983       <entry>29.8.4</entry>
1984       <entry>Inner product</entry>
1985       <entry>Y</entry>
1986       <entry/>
1987     </row>
1988     <row>
1989       <entry>29.8.5</entry>
1990       <entry>Transform reduce</entry>
1991       <entry>Y</entry>
1992       <entry/>
1993     </row>
1994     <row>
1995       <entry>29.8.6</entry>
1996       <entry>Partial sum</entry>
1997       <entry>Y</entry>
1998       <entry/>
1999     </row>
2000     <row>
2001       <entry>29.8.7</entry>
2002       <entry>Exclusive scan</entry>
2003       <entry>Y</entry>
2004       <entry/>
2005     </row>
2006     <row>
2007       <entry>29.8.8</entry>
2008       <entry>Inclusive scan</entry>
2009       <entry>Y</entry>
2010       <entry/>
2011     </row>
2012     <row>
2013       <entry>29.8.9</entry>
2014       <entry>Transform exclusive scan</entry>
2015       <entry>Y</entry>
2016       <entry/>
2017     </row>
2018     <row>
2019       <entry>29.8.10</entry>
2020       <entry>Transform inclusive scan</entry>
2021       <entry>Y</entry>
2022       <entry/>
2023     </row>
2024     <row>
2025       <entry>29.8.11</entry>
2026       <entry>Adjacent difference</entry>
2027       <entry>Y</entry>
2028       <entry/>
2029     </row>
2030     <row>
2031       <entry>29.8.12</entry>
2032       <entry>Iota</entry>
2033       <entry>Y</entry>
2034       <entry/>
2035     </row>
2036     <row>
2037       <entry>29.8.13</entry>
2038       <entry>Greatest common divisor</entry>
2039       <entry>Y</entry>
2040       <entry/>
2041     </row>
2042     <row>
2043       <entry>29.8.14</entry>
2044       <entry>Least common multiple</entry>
2045       <entry>Y</entry>
2046       <entry/>
2047     </row>
2048     <row>
2049       <entry>29.9</entry>
2050       <entry>Mathematical functions for floating-point types</entry>
2051       <entry/>
2052       <entry/>
2053     </row>
2054     <row>
2055       <entry>29.9.1</entry>
2056       <entry>Header <code>&lt;cmath&gt;</code> synopsis</entry>
2057       <entry/>
2058       <entry/>
2059     </row>
2060     <row>
2061       <entry>29.9.2</entry>
2062       <entry>Absolute values</entry>
2063       <entry>Y</entry>
2064       <entry/>
2065     </row>
2066     <row>
2067       <entry>29.9.3</entry>
2068       <entry>Three-dimensional hypotenuse</entry>
2069       <entry>Y</entry>
2070       <entry/>
2071     </row>
2072     <row>
2073       <entry>29.9.4</entry>
2074       <entry>Classification / comparison functions</entry>
2075       <entry>Y</entry>
2076       <entry/>
2077     </row>
2078     <row>
2079       <entry>29.9.5</entry>
2080       <entry>Mathematical special functions</entry>
2081       <entry>Y</entry>
2082       <entry/>
2083     </row>
2084     <row>
2085       <entry>
2086         <emphasis>30</emphasis>
2087       </entry>
2088       <entry namest="c2" nameend="c4" align="left">
2089         <emphasis>Input/output library</emphasis>
2090       </entry>
2091     </row>
2092     <row>
2093       <entry>30.1</entry>
2094       <entry>General</entry>
2095       <entry>Y</entry>
2096       <entry/>
2097     </row>
2098     <row>
2099       <entry>30.2</entry>
2100       <entry>Iostreams requirements</entry>
2101       <entry>Y</entry>
2102       <entry/>
2103     </row>
2104     <row>
2105       <entry>30.2.1</entry>
2106       <entry>Imbue Limitations</entry>
2107       <entry>Y</entry>
2108       <entry/>
2109     </row>
2110     <row>
2111       <entry>30.2.2</entry>
2112       <entry>Positioning Type Limitations</entry>
2113       <entry>Y</entry>
2114       <entry/>
2115     </row>
2116     <row>
2117       <?dbhtml bgcolor="#B0B0B0" ?>
2118       <entry>30.2.3</entry>
2119       <entry>Thread safety</entry>
2120       <entry>Partial</entry>
2121       <entry/>
2122     </row>
2123     <row>
2124       <entry>30.3</entry>
2125       <entry>Forward declarations</entry>
2126       <entry>Y</entry>
2127       <entry/>
2128     </row>
2129     <row>
2130       <entry>30.4</entry>
2131       <entry>Standard iostream objects</entry>
2132       <entry>Y</entry>
2133       <entry/>
2134     </row>
2135     <row>
2136       <entry>30.5</entry>
2137       <entry>Iostreams base classes</entry>
2138       <entry>Y</entry>
2139       <entry/>
2140     </row>
2141     <row>
2142       <entry>30.6</entry>
2143       <entry>Stream buffers</entry>
2144       <entry>Y</entry>
2145       <entry/>
2146     </row>
2147     <row>
2148       <entry>30.7</entry>
2149       <entry>Formatting and manipulators</entry>
2150       <entry>Y</entry>
2151       <entry/>
2152     </row>
2153     <row>
2154       <entry>30.8</entry>
2155       <entry>String-based streams</entry>
2156       <entry>Y</entry>
2157       <entry/>
2158     </row>
2159     <row>
2160       <entry>30.9</entry>
2161       <entry>File-based streams</entry>
2162       <entry>Y</entry>
2163       <entry/>
2164     </row>
2165     <row>
2166       <entry>30.10</entry>
2167       <entry>File systemss</entry>
2168       <entry>Y</entry>
2169       <entry/>
2170     </row>
2171     <row>
2172       <entry>30.11</entry>
2173       <entry>C library files</entry>
2174       <entry>Y</entry>
2175       <entry/>
2176     </row>
2177     <row>
2178       <entry>
2179         <emphasis>31</emphasis>
2180       </entry>
2181       <entry namest="c2" nameend="c4" align="left">
2182         <emphasis>Regular expressions</emphasis>
2183       </entry>
2184     </row>
2185     <row>
2186       <entry>31.1</entry>
2187       <entry>General</entry>
2188       <entry>Y</entry>
2189       <entry/>
2190     </row>
2191     <row>
2192       <entry>31.2</entry>
2193       <entry>Definitions</entry>
2194       <entry>Y</entry>
2195       <entry/>
2196     </row>
2197     <row>
2198       <entry>31.3</entry>
2199       <entry>Requirements</entry>
2200       <entry>Y</entry>
2201       <entry/>
2202     </row>
2203     <row>
2204       <entry>31.4</entry>
2205       <entry>Header <code>&lt;regex&gt;</code> synopsis</entry>
2206       <entry>Y</entry>
2207       <entry/>
2208     </row>
2209     <row>
2210       <entry>31.5</entry>
2211       <entry>Namespace <code>std::regex_constants</code></entry>
2212       <entry>Y</entry>
2213       <entry/>
2214     </row>
2215     <row>
2216       <entry>31.6</entry>
2217       <entry>Class <code>regex_error</code></entry>
2218       <entry>Y</entry>
2219       <entry/>
2220     </row>
2221     <row>
2222       <?dbhtml bgcolor="#B0B0B0" ?>
2223       <entry>31.7</entry>
2224       <entry>Class template <code>regex_traits</code></entry>
2225       <entry>Partial</entry>
2226       <entry><code>transform_primary</code> is not correctly implemented</entry>
2227     </row>
2228     <row>
2229       <entry>31.8</entry>
2230       <entry>Class template <code>basic_regex</code></entry>
2231       <entry>Y</entry>
2232       <entry/>
2233     </row>
2234     <row>
2235       <entry>31.9</entry>
2236       <entry>Class template <code>sub_match</code></entry>
2237       <entry>Y</entry>
2238       <entry/>
2239     </row>
2240     <row>
2241       <entry>31.10</entry>
2242       <entry>Class template <code>match_results</code></entry>
2243       <entry>Y</entry>
2244       <entry/>
2245     </row>
2246     <row>
2247       <entry>31.11</entry>
2248       <entry>Regular expression algorithms</entry>
2249       <entry>Y</entry>
2250       <entry/>
2251     </row>
2252     <row>
2253       <entry>31.12</entry>
2254       <entry>Regular expression Iterators</entry>
2255       <entry>Y</entry>
2256       <entry/>
2257     </row>
2258     <row>
2259       <entry>31.13</entry>
2260       <entry>Modified ECMAScript regular expression grammar</entry>
2261       <entry>Y</entry>
2262       <entry/>
2263     </row>
2264     <row>
2265       <entry>
2266         <emphasis>32</emphasis>
2267       </entry>
2268       <entry namest="c2" nameend="c4" align="left">
2269         <emphasis>Atomic operations</emphasis>
2270       </entry>
2271     </row>
2272     <row>
2273       <entry>32.1</entry>
2274       <entry>General</entry>
2275       <entry>Y</entry>
2276       <entry/>
2277     </row>
2278     <row>
2279       <entry>32.2</entry>
2280       <entry>Header <code>&lt;atomic&gt;</code> synopsis</entry>
2281       <entry>Y</entry>
2282       <entry/>
2283     </row>
2284     <row>
2285       <entry>32.3</entry>
2286       <entry>Type aliases</entry>
2287       <entry>Y</entry>
2288       <entry/>
2289     </row>
2290     <row>
2291       <entry>32.4</entry>
2292       <entry>Order and consistency</entry>
2293       <entry>Y</entry>
2294       <entry/>
2295     </row>
2296     <row>
2297       <entry>32.5</entry>
2298       <entry>Lock-free property</entry>
2299       <entry>Y</entry>
2300       <entry/>
2301     </row>
2302     <row>
2303       <entry>32.6</entry>
2304       <entry>Class template <code>&lt;atomic&gt;</code></entry>
2305       <entry>Y</entry>
2306       <entry/>
2307     </row>
2308     <row>
2309       <entry>32.7</entry>
2310       <entry>Non-member functions</entry>
2311       <entry>Y</entry>
2312       <entry/>
2313     </row>
2314     <row>
2315       <entry>32.8</entry>
2316       <entry>Flag Type and operations</entry>
2317       <entry>Y</entry>
2318       <entry/>
2319     </row>
2320     <row>
2321       <entry>32.9</entry>
2322       <entry>Fences</entry>
2323       <entry>Y</entry>
2324       <entry/>
2325     </row>
2326     <row>
2327       <entry>
2328         <emphasis>33</emphasis>
2329       </entry>
2330       <entry namest="c2" nameend="c4" align="left">
2331         <emphasis>Thread support</emphasis>
2332       </entry>
2333     </row>
2334     <row>
2335       <entry>33.1</entry>
2336       <entry>General</entry>
2337       <entry>Y</entry>
2338       <entry/>
2339     </row>
2340     <row>
2341       <entry>33.2</entry>
2342       <entry>Requirements</entry>
2343       <entry>Y</entry>
2344       <entry/>
2345     </row>
2346     <row>
2347       <entry>33.3</entry>
2348       <entry>Threads</entry>
2349       <entry/>
2350       <entry/>
2351     </row>
2352     <row>
2353       <entry>33.3.1</entry>
2354       <entry>Header <code>thread</code> synopsis</entry>
2355       <entry/>
2356       <entry/>
2357     </row>
2358     <row>
2359       <entry>33.3.2</entry>
2360       <entry>Class <code>thread</code></entry>
2361       <entry>Y</entry>
2362       <entry/>
2363     </row>
2364     <row>
2365       <?dbhtml bgcolor="#B0B0B0" ?>
2366       <entry>33.3.2.1</entry>
2367       <entry>Class <code>thread</code></entry>
2368       <entry>Partial</entry>
2369       <entry><code>thread::id</code> comparisons not well-defined</entry>
2370     </row>
2371     <row>
2372       <entry>33.3.3</entry>
2373       <entry>Namespace <code>this_thread</code></entry>
2374       <entry>Y</entry>
2375       <entry/>
2376     </row>
2377     <row>
2378       <entry>33.4</entry>
2379       <entry>Mutual exclusion</entry>
2380       <entry/>
2381       <entry/>
2382     </row>
2383     <row>
2384       <entry>33.4.3</entry>
2385       <entry>Mutex requirements</entry>
2386       <entry/>
2387       <entry/>
2388     </row>
2389     <row>
2390       <entry>33.4.3.1</entry>
2391       <entry>In general</entry>
2392       <entry/>
2393       <entry/>
2394     </row>
2395     <row>
2396       <entry>33.4.3.2</entry>
2397       <entry>Mutex types</entry>
2398       <entry/>
2399       <entry/>
2400     </row>
2401     <row>
2402       <entry>33.4.3.2.1</entry>
2403       <entry>Class <code>mutex</code></entry>
2404       <entry>Y</entry>
2405       <entry/>
2406     </row>
2407     <row>
2408       <entry>33.4.3.2.2</entry>
2409       <entry>Class <code>recursive_mutex</code></entry>
2410       <entry>Y</entry>
2411       <entry/>
2412     </row>
2413     <row>
2414       <entry>33.4.3.3</entry>
2415       <entry>Timed mutex types</entry>
2416       <entry/>
2417       <entry/>
2418     </row>
2419     <row>
2420       <entry>33.4.3.3.1</entry>
2421       <entry>Class <code>timed_mutex</code></entry>
2422       <entry>Y</entry>
2423       <entry/>
2424     </row>
2425     <row>
2426       <entry>33.4.3.3.2</entry>
2427       <entry>Class <code>recursive_timed_mutex</code></entry>
2428       <entry>Y</entry>
2429       <entry/>
2430     </row>
2431     <row>
2432       <entry>33.4.3.4</entry>
2433       <entry>Shared mutex types</entry>
2434       <entry/>
2435       <entry/>
2436     </row>
2437     <row>
2438       <entry>33.4.3.4.1</entry>
2439       <entry>Class <code>shared_mutex</code></entry>
2440       <entry>Y</entry>
2441       <entry/>
2442     </row>
2443     <row>
2444       <entry>33.4.3.5</entry>
2445       <entry>Shared timed mutex types</entry>
2446       <entry/>
2447       <entry/>
2448     </row>
2449     <row>
2450       <entry>33.4.3.5.1</entry>
2451       <entry>Class <code>shared_timed_mutex</code></entry>
2452       <entry>Y</entry>
2453       <entry/>
2454     </row>
2455     <row>
2456       <entry>33.4.4</entry>
2457       <entry>Locks</entry>
2458       <entry/>
2459       <entry/>
2460     </row>
2461     <row>
2462       <entry>33.4.4.1</entry>
2463       <entry>Class template <code>lock_guard</code></entry>
2464       <entry>Y</entry>
2465       <entry/>
2466     </row>
2467     <row>
2468       <entry>33.4.4.2</entry>
2469       <entry>Class template <code>scoped_guard</code></entry>
2470       <entry>Y</entry>
2471       <entry/>
2472     </row>
2473     <row>
2474       <entry>33.4.4.3</entry>
2475       <entry>Class template <code>unique_lock</code></entry>
2476       <entry>Y</entry>
2477       <entry/>
2478     </row>
2479     <row>
2480       <entry>33.4.4.4</entry>
2481       <entry>Class template <code>shared_lock</code></entry>
2482       <entry>Y</entry>
2483       <entry/>
2484     </row>
2485     <row>
2486       <entry>33.4.5</entry>
2487       <entry>Generic locking algorithms</entry>
2488       <entry>Y</entry>
2489       <entry/>
2490     </row>
2491     <row>
2492       <entry>33.4.6</entry>
2493       <entry>Call once</entry>
2494       <entry/>
2495       <entry/>
2496     </row>
2497     <row>
2498       <entry>33.4.6.1</entry>
2499       <entry>Struct <code>once_flag</code></entry>
2500       <entry>Y</entry>
2501       <entry/>
2502     </row>
2503     <row>
2504       <?dbhtml bgcolor="#B0B0B0" ?>
2505       <entry>33.4.6.2</entry>
2506       <entry>Function <code>call_once</code></entry>
2507       <entry>Y</entry>
2508       <entry>Exception support is broken.
2509         See <link xmlns:xlink="http://www.w3.org/1999/xlink"
2510         xlink:href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66146">PR
2511         66146</link>.
2512       </entry>
2513     </row>
2514     <row>
2515       <entry>33.5</entry>
2516       <entry>Condition variables</entry>
2517       <entry>Y</entry>
2518       <entry/>
2519     </row>
2520     <row>
2521       <entry>33.5.1</entry>
2522       <entry>Class <code>condition_variable</code></entry>
2523       <entry>Y</entry>
2524       <entry/>
2525     </row>
2526     <row>
2527       <entry>33.5.2</entry>
2528       <entry>Class <code>condition_variable_any</code></entry>
2529       <entry>Y</entry>
2530       <entry/>
2531     </row>
2532     <row>
2533       <entry>33.6</entry>
2534       <entry>Futures</entry>
2535       <entry/>
2536       <entry/>
2537     </row>
2538     <row>
2539       <entry>33.6.1</entry>
2540       <entry>Overview</entry>
2541       <entry/>
2542       <entry/>
2543     </row>
2544     <row>
2545       <entry>33.6.2</entry>
2546       <entry>Header <code>&lt;future&gt;</code></entry>
2547       <entry/>
2548       <entry/>
2549     </row>
2550     <row>
2551       <entry>33.6.3</entry>
2552       <entry>Error handling</entry>
2553       <entry>Y</entry>
2554       <entry/>
2555     </row>
2556     <row>
2557       <entry>33.6.4</entry>
2558       <entry>Class <code>future_error</code></entry>
2559       <entry>Y</entry>
2560       <entry/>
2561     </row>
2562     <row>
2563       <entry>33.6.5</entry>
2564       <entry>Shared state</entry>
2565       <entry>Y</entry>
2566       <entry/>
2567     </row>
2568     <row>
2569       <entry>33.6.6</entry>
2570       <entry>Class template <code>promise</code></entry>
2571       <entry>Y</entry>
2572       <entry/>
2573     </row>
2574     <row>
2575       <entry>33.6.7</entry>
2576       <entry>Class template <code>future</code></entry>
2577       <entry>Y</entry>
2578       <entry/>
2579     </row>
2580     <row>
2581       <entry>33.6.8</entry>
2582       <entry>Class template <code>shared_future</code></entry>
2583       <entry>Y</entry>
2584       <entry/>
2585     </row>
2586     <row>
2587       <entry>33.6.9</entry>
2588       <entry>Function template <code>async</code></entry>
2589       <entry>Y</entry>
2590       <entry/>
2591     </row>
2592     <row>
2593       <entry>33.6.10</entry>
2594       <entry>Class template <code>packaged_task</code></entry>
2595       <entry>Y</entry>
2596       <entry/>
2597     </row>
2598     <row>
2599       <entry>
2600         <emphasis>Appendix D</emphasis>
2601       </entry>
2602       <entry namest="c2" nameend="c4" align="left">
2603         <emphasis>Compatibility features</emphasis>
2604       </entry>
2605     </row>
2606     <row>
2607       <entry>D.4</entry>
2608       <entry>C++ standard library headers</entry>
2609       <entry>Y</entry>
2610       <entry/>
2611     </row>
2612     <row>
2613       <entry>D.4.1</entry>
2614       <entry>Header <code>&lt;ccomplex&gt;</code> synopsis</entry>
2615       <entry>Y</entry>
2616       <entry/>
2617     </row>
2618     <row>
2619       <entry>D.4.1</entry>
2620       <entry>Header <code>&lt;cstdalign&gt;</code> synopsis</entry>
2621       <entry>Y</entry>
2622       <entry/>
2623     </row>
2624     <row>
2625       <entry>D.4.1</entry>
2626       <entry>Header <code>&lt;cstdbool&gt;</code> synopsis</entry>
2627       <entry>Y</entry>
2628       <entry/>
2629     </row>
2630     <row>
2631       <entry>D.4.1</entry>
2632       <entry>Header <code>&lt;ctgmath&gt;</code> synopsis</entry>
2633       <entry>Y</entry>
2634       <entry/>
2635     </row>
2636     <row>
2637       <entry>D.5</entry>
2638       <entry>C standard library headers</entry>
2639       <entry>Y</entry>
2640       <entry/>
2641     </row>
2642     <row>
2643       <entry>D.6</entry>
2644       <entry><code>char*</code> streams</entry>
2645       <entry>Y</entry>
2646       <entry/>
2647     </row>
2648     <row>
2649       <entry>D.7</entry>
2650       <entry><code>uncaught_exception</code></entry>
2651       <entry>Y</entry>
2652       <entry/>
2653     </row>
2654     <row>
2655       <entry>D.8</entry>
2656       <entry>Old adaptable function bindings</entry>
2657       <entry>Y</entry>
2658       <entry/>
2659     </row>
2660     <row>
2661       <entry>D.9</entry>
2662       <entry>The default allocator</entry>
2663       <entry>Y</entry>
2664       <entry/>
2665     </row>
2666     <row>
2667       <entry>D.10</entry>
2668       <entry>Raw storage iterator</entry>
2669       <entry>Y</entry>
2670       <entry/>
2671     </row>
2672     <row>
2673       <entry>D.11</entry>
2674       <entry>Temporary buffers</entry>
2675       <entry>Y</entry>
2676       <entry/>
2677     </row>
2678     <row>
2679       <entry>D.12</entry>
2680       <entry>Deprecated type traits</entry>
2681       <entry>Y</entry>
2682       <entry/>
2683     </row>
2684     <row>
2685       <entry>D.13</entry>
2686       <entry>Deprecated iterator primitives</entry>
2687       <entry>Y</entry>
2688       <entry/>
2689     </row>
2690     <row>
2691       <entry>D.14</entry>
2692       <entry>Deprecated <code>shared_ptr</code> observers</entry>
2693       <entry>Y</entry>
2694       <entry/>
2695     </row>
2696     <row>
2697       <entry>D.15</entry>
2698       <entry>Deprecated standard code conversion facets</entry>
2699       <entry>Y</entry>
2700       <entry/>
2701     </row>
2702     <row>
2703       <entry>D.16</entry>
2704       <entry>Deprecated convenience conversion interfaces</entry>
2705       <entry>Y</entry>
2706       <entry/>
2707     </row>
2708
2709   </tbody>
2710 </tgroup>
2711 </table>
2712
2713 <table frame="all" xml:id="table.cxx17_ts_status">
2714 <title>C++ Technical Specifications Implementation Status</title>
2715
2716 <tgroup cols="4" align="left" colsep="0" rowsep="1">
2717 <colspec colname="c1"/>
2718 <colspec colname="c2"/>
2719 <colspec colname="c3"/>
2720 <colspec colname="c4"/>
2721   <thead>
2722     <row>
2723       <entry>Paper</entry>
2724       <entry>Title</entry>
2725       <entry>Status</entry>
2726       <entry>Comments</entry>
2727     </row>
2728   </thead>
2729
2730   <tbody>
2731
2732     <row>
2733       <entry>
2734         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4076.html">
2735           N4076
2736         </link>
2737       </entry>
2738       <entry>A generalized callable negator</entry>
2739       <entry>Y</entry>
2740       <entry>Library Fundamentals 2 TS</entry>
2741     </row>
2742
2743     <row>
2744       <entry>
2745         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4273.htm">
2746           N4273
2747         </link>
2748       </entry>
2749       <entry>Uniform Container Erasure</entry>
2750       <entry>Y</entry>
2751       <entry>Library Fundamentals 2 TS</entry>
2752     </row>
2753
2754     <row>
2755       <entry>
2756         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4061.pdf">
2757           N4061
2758         </link>
2759       </entry>
2760       <entry>Greatest Common Divisor and Least Common Multiple</entry>
2761       <entry>Y</entry>
2762       <entry>Library Fundamentals 2 TS</entry>
2763     </row>
2764
2765     <row>
2766       <entry>
2767         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4066.htm">
2768           N4066
2769         </link>
2770       </entry>
2771       <entry>Delimited iterators</entry>
2772       <entry>Y</entry>
2773       <entry>Library Fundamentals 2 TS</entry>
2774     </row>
2775
2776     <row>
2777       <entry>
2778         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4282.pdf">
2779           N4282
2780         </link>
2781       </entry>
2782       <entry>The World's Dumbest Smart Pointer</entry>
2783       <entry>Y</entry>
2784       <entry>Library Fundamentals 2 TS</entry>
2785     </row>
2786
2787
2788     <row>
2789       <entry>
2790         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4388.html">
2791           N4388
2792         </link>
2793       </entry>
2794       <entry>Const-Propagating Wrapper</entry>
2795       <entry>Y</entry>
2796       <entry>Library Fundamentals 2 TS</entry>
2797     </row>
2798
2799     <row>
2800       <entry>
2801         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4391.html">
2802           N4391
2803         </link>
2804       </entry>
2805       <entry> <code>make_array</code>, revision 4 </entry>
2806       <entry>Y</entry>
2807       <entry>Library Fundamentals 2 TS</entry>
2808     </row>
2809
2810     <row>
2811       <entry>
2812         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4502.pdf">
2813           N4502
2814         </link>
2815       </entry>
2816       <entry> Support for the C++ Detection Idiom, V2 </entry>
2817       <entry>Y</entry>
2818       <entry>Library Fundamentals 2 TS</entry>
2819     </row>
2820
2821     <row>
2822       <entry>
2823         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4519.pdf">
2824           N4519
2825         </link>
2826       </entry>
2827       <entry> Source-Code Information Capture </entry>
2828       <entry>Y</entry>
2829       <entry>Library Fundamentals 2 TS</entry>
2830     </row>
2831
2832     <row>
2833       <?dbhtml bgcolor="#C8B0B0" ?>
2834       <entry>
2835         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4521.html">
2836           N4521
2837         </link>
2838       </entry>
2839       <entry> Merge Fundamentals V1 into V2 </entry>
2840       <entry>
2841         N (components from V1 are still in namespace
2842         <code>fundamentals_v1</code>)
2843       </entry>
2844       <entry>Library Fundamentals 2 TS</entry>
2845     </row>
2846
2847     <row>
2848       <entry>
2849         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/p0013r1.html">
2850           P0013R1
2851         </link>
2852       </entry>
2853       <entry>Logical Operator Type Traits (revision 1)</entry>
2854       <entry>Y</entry>
2855       <entry>Library Fundamentals 2 TS</entry>
2856     </row>
2857
2858     <row>
2859       <entry>
2860         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4531.html">
2861           N4531
2862         </link>
2863       </entry>
2864       <entry>std::rand replacement, revision 3</entry>
2865       <entry>Y</entry>
2866       <entry>Library Fundamentals 2 TS</entry>
2867     </row>
2868
2869     <row>
2870       <entry>
2871         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0214r9.pdf">
2872           P0214R9
2873         </link>
2874       </entry>
2875       <entry>Data-Parallel Types</entry>
2876       <entry>Y</entry>
2877       <entry>Parallelism 2 TS</entry>
2878     </row>
2879
2880   </tbody>
2881 </tgroup>
2882 </table>
2883
2884 <section xml:id="iso.2017.specific" xreflabel="Implementation Specific"><info><title>Implementation Specific Behavior</title></info>
2885
2886    <para>For behaviour which is also specified by previous standards,
2887       see <link linkend="iso.1998.specific">C++ 1998/2003 Implementation
2888       Specific Behavior</link> and <link linkend="iso.2011.specific">C++
2889       2011 Implementation Specific Behavior</link>. This section only
2890       documents behaviour which is new in the 2017 standard.
2891    </para>
2892
2893    <para>
2894       <emphasis>20.5.1.2 [headers]</emphasis>
2895       Whether names from Annex K are declared by C++ headers depends on
2896       whether the underlying C library supports Annex K and declares the
2897       names. For the GNU C library, there is no Annex K support and so
2898       none of its names are declared by C++ headers.
2899    </para>
2900
2901    <para>
2902       <emphasis>23.6.5 [optional.bad_optional_access]</emphasis>
2903       <code>what()</code> returns <literal>"bad optional access"</literal>.
2904    </para>
2905
2906    <para>
2907       <emphasis>23.7.3 [variant.variant]</emphasis>
2908       <classname>variant</classname> supports over-aligned types.
2909    </para>
2910
2911    <para>
2912       <emphasis>23.7.10 [variant.bad.access]</emphasis>
2913       <code>what()</code> returns one of the strings
2914       <literal>"std::get: variant is valueless"</literal>,
2915       <literal>"std::get: wrong index for variant"</literal>,
2916       <literal>"std::visit: variant is valueless"</literal>,
2917       or <literal>"std::visit&lt;R&gt;: variant is valueless"</literal>.
2918    </para>
2919
2920    <para>
2921       <emphasis>23.12.5.2 [memory.resource.pool.options]</emphasis>
2922       Let S equal <code>numeric_limits&lt;size_t&gt;::digits</code>.
2923       The limit for maximum number of blocks in a chunk is given by
2924       <inlineequation><mathphrase>2<superscript>N</superscript>-1</mathphrase></inlineequation>,
2925       where N is <inlineequation><mathphrase>min(19, 3 + S/2)</mathphrase></inlineequation>.
2926       The largest allocation size that will be allocated from a pool is
2927       <inlineequation><mathphrase>2<superscript>22</superscript></mathphrase></inlineequation>
2928       when <inlineequation><mathphrase>S > 20</mathphrase></inlineequation>,
2929       otherwise 3072 when <inlineequation><mathphrase>S > 16</mathphrase></inlineequation>,
2930       otherwise 768.
2931    </para>
2932
2933    <para>
2934       <emphasis>23.12.6.1 [memory.resource.monotonic.buffer.ctor]</emphasis>
2935       The default <code>next_buffer_size</code> is <code>128 * sizeof(void*)</code>.
2936       The default growth factor is <code>1.5</code>.
2937    </para>
2938
2939    <para>
2940       <emphasis>23.15.4.3 [meta.unary.prop]</emphasis>
2941       The predicate condition for
2942       <code>has_unique_object_representations</code> is true for all scalar
2943       types except floating point types.
2944    </para>
2945
2946    <para>
2947       <emphasis>23.19.3 [execpol.type],
2948       28.4.3 [algorithms.parallel.exec]</emphasis>
2949       There are no implementation-defined execution policies.
2950    </para>
2951
2952    <para>
2953       <emphasis>24.4.2 [string.view.template]</emphasis>
2954       <classname>basic_string_view&lt;C, T&gt;::iterator</classname> is
2955       <code>C*</code> and
2956       <classname>basic_string_view&lt;C, T&gt;::const_iterator</classname> is
2957       <code>const C*</code>.
2958    </para>
2959
2960
2961    <para>
2962       <emphasis>28.4.3 [algorithms.parallel.exec]</emphasis>
2963       Threads of execution created by <classname>std::thread</classname>
2964       provide concurrent forward progress guarantees, so threads of execution
2965       implicitly created by the library will provide parallel forward
2966       progress guarantees.
2967    </para>
2968
2969    <para>
2970       <emphasis>29.4.1 [cfenv.syn]</emphasis>
2971       The effects of the <filename>&lt;cfenv&gt;</filename> functions
2972       depends on whether the <code>FENV_ACCESS</code> pragma is supported,
2973       and on the C library that provides the header.
2974    </para>
2975
2976    <para>
2977       <emphasis>29.6.9 [c.math.rand]</emphasis>
2978       Whether the <function>rand</function> function may introduce data
2979       races depends on the target C library that provides the function.
2980    </para>
2981
2982    <para>
2983       <emphasis>29.9.5 [sf.cmath]</emphasis>
2984       The effect of calling the mathematical special functions with large
2985       inputs should be documented here.
2986    </para>
2987
2988    <para>
2989       <emphasis>30.10.2.1 [fs.conform.9945]</emphasis>
2990       The behavior of the filesystem library implementation will depend on
2991       the target operating system. Some features will not be supported
2992       on some targets. Symbolic links and file permissions
2993       are not supported on Windows.
2994    </para>
2995
2996    <para>
2997       <emphasis>30.10.5 [fs.filesystem.syn]</emphasis>
2998       The clock used for file times is an unspecified type
2999       with a signed 64-bit representation, capable of representing
3000       timestamps with nanosecond resolution. The clock's epoch is
3001       unspecified, but is not the same as the system clock's epoch.
3002    </para>
3003
3004    <para>
3005       <emphasis>30.10.7.1 [fs.path.generic]</emphasis>
3006       dot-dot in the root-directory refers to the root-directory itself.
3007       On Windows, a drive specifier such as <code>"C:"</code> or
3008       <code>"z:"</code> is treated as a root-name. On Cygwin, a path
3009       that begins with two successive directory separators is a
3010       root-name. Otherwise (for POSIX-like systems other than Cygwin),
3011       the implementation-defined root-name is an unspecified string
3012       which does not appear in any pathnames.
3013    </para>
3014
3015    <para>
3016       <emphasis>30.10.10.1 [fs.enum.path.format]</emphasis>
3017       The character sequence is always interpreted in the native pathname
3018       format.
3019    </para>
3020
3021    <para>
3022       <emphasis>30.10.15.4 [fs.op.file_size]</emphasis>
3023       If <code>!is_regular_file(p)</code>, an error is reported.
3024    </para>
3025
3026     <para>
3027       <emphasis>30.10.15.32 [fs.op.rename]</emphasis>
3028       On Windows, <code>filesystem::rename</code>
3029       is implemented by calling <code>MoveFileExW</code> and so
3030       does not meet the requirements of POSIX <code>rename</code>
3031       when one or both of the paths resolves to an existing directory.
3032       Specifically, it is not possible to rename a directory to replace another
3033       directory (POSIX requires that to work if the directory being
3034       replaced is empty).
3035     </para>
3036
3037
3038    <section xml:id="iso.2017.par2ts" xreflabel="Implementation Specific Behavior of the Parallelism 2 TS"><info><title>Parallelism 2 TS</title></info>
3039
3040      <para>
3041         <emphasis>9.3 [parallel.simd.abi]</emphasis>
3042         <code>max_fixed_size&lt;T&gt;</code> is 32, except when targetting
3043         AVX512BW and <code>sizeof(T)</code> is 1.
3044      </para>
3045
3046      <para>
3047         When targeting 32-bit x86,
3048         <classname>simd_abi::compatible&lt;T&gt;</classname> is an alias for
3049         <classname>simd_abi::scalar</classname>.
3050         When targeting 64-bit x86 (including x32) or Aarch64,
3051         <classname>simd_abi::compatible&lt;T&gt;</classname> is an alias for
3052         <classname>simd_abi::_VecBuiltin&lt;16&gt;</classname>,
3053         unless <code>T</code> is <code>long double</code>, in which case it is
3054         an alias for <classname>simd_abi::scalar</classname>.
3055         When targeting ARM (but not Aarch64) with NEON support,
3056         <classname>simd_abi::compatible&lt;T&gt;</classname> is an alias for
3057         <classname>simd_abi::_VecBuiltin&lt;16&gt;</classname>,
3058         unless <code>sizeof(T) &gt; 4</code>, in which case it is
3059         an alias for <classname>simd_abi::scalar</classname>. Additionally,
3060         <classname>simd_abi::compatible&lt;float&gt;</classname> is an alias for
3061         <classname>simd_abi::scalar</classname> unless compiling with
3062         -ffast-math.
3063      </para>
3064
3065      <para>
3066         When targeting x86 (both 32-bit and 64-bit),
3067         <classname>simd_abi::native&lt;T&gt;</classname> is an alias for one of
3068         <classname>simd_abi::scalar</classname>,
3069         <classname>simd_abi::_VecBuiltin&lt;16&gt;</classname>,
3070         <classname>simd_abi::_VecBuiltin&lt;32&gt;</classname>, or
3071         <classname>simd_abi::_VecBltnBtmsk&lt;64&gt;</classname>, depending on
3072         <code>T</code> and the machine options the compiler was invoked with.
3073      </para>
3074
3075      <para>
3076         When targeting ARM/Aarch64 or POWER,
3077         <classname>simd_abi::native&lt;T&gt;</classname> is an alias for
3078         <classname>simd_abi::scalar</classname> or
3079         <classname>simd_abi::_VecBuiltin&lt;16&gt;</classname>, depending on
3080         <code>T</code> and the machine options the compiler was invoked with.
3081      </para>
3082
3083      <para>
3084         For any other targeted machine
3085         <classname>simd_abi::compatible&lt;T&gt;</classname> and
3086         <classname>simd_abi::native&lt;T&gt;</classname> are aliases for
3087         <classname>simd_abi::scalar</classname>. (subject to change)
3088      </para>
3089
3090      <para>
3091         The extended ABI tag types defined in the
3092         <code>std::experimental::parallelism_v2::simd_abi</code> namespace are:
3093         <classname>simd_abi::_VecBuiltin&lt;Bytes&gt;</classname>, and
3094         <classname>simd_abi::_VecBltnBtmsk&lt;Bytes&gt;</classname>.
3095      </para>
3096
3097      <para>
3098         <classname>simd_abi::deduce&lt;T, N, Abis...&gt;::type</classname>,
3099         with <code>N &gt; 1</code> is an alias for an extended ABI tag, if a
3100         supported extended ABI tag exists. Otherwise it is an alias for
3101         <classname>simd_abi::fixed_size&lt;N&gt;</classname>. The <classname>
3102         simd_abi::_VecBltnBtmsk</classname> ABI tag is preferred over
3103         <classname>simd_abi::_VecBuiltin</classname>.
3104      </para>
3105
3106      <para>
3107         <emphasis>9.4 [parallel.simd.traits]</emphasis>
3108         <classname>memory_alignment&lt;T, U&gt;::value</classname> is
3109         <code>sizeof(U) * T::size()</code> rounded up to the next power-of-two
3110         value.
3111      </para>
3112
3113      <para>
3114         <emphasis>9.6.1 [parallel.simd.overview]</emphasis>
3115         On ARM, <classname>simd&lt;T, _VecBuiltin&lt;Bytes&gt;&gt;</classname>
3116         is supported if <code>__ARM_NEON</code> is defined and
3117         <code>sizeof(T) &lt;= 4</code>. Additionally,
3118         <code>sizeof(T) == 8</code> with integral <code>T</code> is supported if
3119         <code>__ARM_ARCH &gt;= 8</code>, and <code>double</code> is supported if
3120         <code>__aarch64__</code> is defined.
3121
3122         On POWER, <classname>simd&lt;T, _VecBuiltin&lt;Bytes&gt;&gt;</classname>
3123         is supported if <code>__ALTIVEC__</code> is defined and <code>sizeof(T)
3124         &lt; 8</code>. Additionally, <code>double</code> is supported if
3125         <code>__VSX__</code> is defined, and any <code>T</code> with <code>
3126         sizeof(T) &lt;= 8</code> is supported if <code>__POWER8_VECTOR__</code>
3127         is defined.
3128
3129         On x86, given an extended ABI tag <code>Abi</code>,
3130         <classname>simd&lt;T, Abi&gt;</classname> is supported according to the
3131         following table:
3132         <table frame="all" xml:id="table.par2ts_simd_support">
3133           <title>Support for Extended ABI Tags</title>
3134
3135           <tgroup cols="4" align="left" colsep="0" rowsep="1">
3136           <colspec colname="c1"/>
3137           <colspec colname="c2"/>
3138           <colspec colname="c3"/>
3139           <colspec colname="c4"/>
3140             <thead>
3141               <row>
3142                 <entry>ABI tag <code>Abi</code></entry>
3143                 <entry>value type <code>T</code></entry>
3144                 <entry>values for <code>Bytes</code></entry>
3145                 <entry>required machine option</entry>
3146               </row>
3147             </thead>
3148
3149             <tbody>
3150               <row>
3151                 <entry morerows="5">
3152                   <classname>_VecBuiltin&lt;Bytes&gt;</classname>
3153                 </entry>
3154                 <entry morerows="1"><code>float</code></entry>
3155                 <entry>8, 12, 16</entry>
3156                 <entry>"-msse"</entry>
3157               </row>
3158
3159               <row>
3160                 <entry>20, 24, 28, 32</entry>
3161                 <entry>"-mavx"</entry>
3162               </row>
3163
3164               <row>
3165                 <entry morerows="1"><code>double</code></entry>
3166                 <entry>16</entry>
3167                 <entry>"-msse2"</entry>
3168               </row>
3169
3170               <row>
3171                 <entry>24, 32</entry>
3172                 <entry>"-mavx"</entry>
3173               </row>
3174
3175               <row>
3176                 <entry morerows="1">
3177                   integral types other than <code>bool</code>
3178                 </entry>
3179                 <entry>
3180                   <code>Bytes</code> ≤ 16 and <code>Bytes</code> divisible by
3181                   <code>sizeof(T)</code>
3182                 </entry>
3183                 <entry>"-msse2"</entry>
3184               </row>
3185
3186               <row>
3187                 <entry>
3188                   16 &lt; <code>Bytes</code> ≤ 32 and <code>Bytes</code>
3189                   divisible by <code>sizeof(T)</code>
3190                 </entry>
3191                 <entry>"-mavx2"</entry>
3192               </row>
3193
3194               <row>
3195                 <entry morerows="1">
3196                   <classname>_VecBuiltin&lt;Bytes&gt;</classname> and
3197                   <classname>_VecBltnBtmsk&lt;Bytes&gt;</classname>
3198                 </entry>
3199                 <entry>
3200                   vectorizable types with <code>sizeof(T)</code> ≥ 4
3201                 </entry>
3202                 <entry morerows="1">
3203                   32 &lt; <code>Bytes</code> ≤ 64 and <code>Bytes</code>
3204                   divisible by <code>sizeof(T)</code>
3205                 </entry>
3206                 <entry>"-mavx512f"</entry>
3207               </row>
3208
3209               <row>
3210                 <entry>
3211                   vectorizable types with <code>sizeof(T)</code> &lt; 4
3212                 </entry>
3213                 <entry>"-mavx512bw"</entry>
3214               </row>
3215
3216               <row>
3217                 <entry morerows="1">
3218                   <classname>_VecBltnBtmsk&lt;Bytes&gt;</classname>
3219                 </entry>
3220                 <entry>
3221                   vectorizable types with <code>sizeof(T)</code> ≥ 4
3222                 </entry>
3223                 <entry morerows="1">
3224                   <code>Bytes</code> ≤ 32 and <code>Bytes</code> divisible by
3225                   <code>sizeof(T)</code>
3226                 </entry>
3227                 <entry>"-mavx512vl"</entry>
3228               </row>
3229
3230               <row>
3231                 <entry>
3232                   vectorizable types with <code>sizeof(T)</code> &lt; 4
3233                 </entry>
3234                 <entry>"-mavx512bw" and "-mavx512vl"</entry>
3235               </row>
3236
3237             </tbody>
3238           </tgroup>
3239         </table>
3240      </para>
3241
3242    </section>
3243
3244 </section>
3245
3246 </section>