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  26 <!--*************************************************************************-->
  27 <h1>C++ Support in Clang</h1>
  28 <!--*************************************************************************-->
  29
  30 <p>Clang implements the following published and upcoming ISO C++ standards:</p>
  31
  32 <table width="689" border="1" cellspacing="0">
  33  <tr>
  34   <th>Language Standard</th>
  35   <th>Flag</th>
  36   <th>Available in Clang?</th>
  37  </tr>
  38  <tr>
  39   <td><a href="#cxx26">C++2c</a></td>
  40   <td><tt>-std=c++2c</tt></td>
  41   <td class="partial" align="center">Partial</td>
  42  </tr>
  43 <tr>
  44   <td><a href="#cxx23">C++23</a></td>
  45   <td><tt>-std=c++23</tt></td>
  46   <td class="partial" align="center">Partial</td>
  47  </tr>
  48  <tr>
  49   <td><a href="#cxx20">C++20</a></td>
  50   <td><tt>-std=c++20</tt></td>
  51   <td class="partial" align="center">Partial</td>
  52  </tr>
  53  <tr>
  54   <td><a href="#cxx17">C++17</a></td>
  55   <td><tt>-std=c++17</tt></td>
  56   <td class="full" align="center">Clang 5</td>
  57  </tr>
  58  <tr>
  59   <td><a href="#cxx14">C++14</a></td>
  60   <td><tt>-std=c++14</tt></td>
  61   <td class="full" align="center">Clang 3.4</td>
  62  </tr>
  63  <tr>
  64   <td><a href="#cxx11">C++11</a></td>
  65   <td><tt>-std=c++11</tt></td>
  66   <td class="full" align="center">Clang 3.3</td>
  67  </tr>
  68  <tr>
  69   <td><a href="#cxx98">C++98 / C++03</a></td>
  70   <td><tt>-std=c++98</tt></td>
  71   <td class="full" align="center">Yes (other than <tt>export</tt>)</td>
  72 </tr>
  73 </table>
  74
  75 <p>The Clang community is continually striving to improve C++ standards
  76 compliance between releases by submitting and tracking <a
  77 href="cxx_dr_status.html">C++ Defect Reports</a> and implementing resolutions
  78 as they become available.</p>
  79
  80 <p>Experimental work is also under way to implement <a href="#ts">C++ Technical
  81 Specifications</a> that will help drive the future of the C++ programming
  82 language.</p>
  83
  84 <p>The <a href="https://github.com/llvm/llvm-project/issues/">LLVM bug tracker</a> uses
  85 the "c++" label, as well as mode-specific labels such as "c++11", "c++14",
  86 and so on, to track known bugs with Clang's language conformance.</p>
  87
  88 <h2 id="cxx26">C++2c implementation status</h2>
  89
  90 <!-- TODO add link to the ISO Standard after it's published. -->
  91 <p>Clang has support for some of the features of the C++ standard following
  92 C++23, informally referred to as C++26.</p>
  93
  94 <p>You can use Clang in C++2c mode with the <code>-std=c++2c</code> option.</p>
  95
  96 <details open>
  97 <summary>List of features and minimum Clang version with support</summary>
  98 <table width="689" border="1" cellspacing="0">
  99  <tr>
 100     <th>Language Feature</th>
 101     <th>C++26 Proposal</th>
 102     <th>Available in Clang?</th>
 103  </tr>
 104  <!-- Spring 2023 papers (Varna) -->
 105  <tr>
 106   <td>Remove undefined behavior from lexing</td>
 107   <td><a href="https://wg21.link/P2621R2">P2621R2</a> (<a href="#dr">DR</a>)</td>
 108   <td class="full" align="center">Clang 3.3</td>
 109  </tr>
 110  <tr>
 111   <td>Making non-encodable string literals ill-formed</td>
 112   <td><a href="https://wg21.link/P1854R4">P1854R4</a> (<a href="#dr">DR</a>)</td>
 113   <td class="full" align="center">Clang 14</td>
 114  </tr>
 115  <tr>
 116   <td>Unevaluated strings</td>
 117   <td><a href="https://wg21.link/P2361R6">P2361R6</a></td>
 118   <td class="unreleased" align="center">Clang 18</td>
 119  </tr>
 120  <tr>
 121   <td>Add @, $, and ` to the basic character set</td>
 122   <td><a href="https://wg21.link/P2558R2">P2558R2</a></td>
 123   <td class="full" align="center">Yes</td>
 124  </tr>
 125  <tr>
 126   <td>constexpr cast from <tt>void*</tt></td>
 127   <td><a href="https://wg21.link/P2738R1">P2738R1</a></td>
 128   <td class="full" align="center">Clang 17</td>
 129  </tr>
 130  <tr>
 131   <td>On the ignorability of standard attributes</td>
 132   <td><a href="https://wg21.link/P2552R3">P2552R3</a> (<a href="#dr">DR</a>)</td>
 133   <td class="none" align="center">No</td>
 134  </tr>
 135  <tr>
 136   <td>Static storage for braced initializers</td>
 137   <td><a href="https://wg21.link/P2752R3">P2752R3</a> (<a href="#dr">DR</a>)</td>
 138   <td class="none" align="center">No</td>
 139  </tr>
 140  <tr>
 141   <td>User-generated <tt>static_assert</tt> messages</td>
 142   <td><a href="https://wg21.link/P2741R3">P2741R3</a></td>
 143   <td class="full" align="center">Clang 17</td>
 144  </tr>
 145  <tr>
 146   <td>Placeholder variables with no name</td>
 147   <td><a href="https://wg21.link/P2169R4">P2169R4</a></td>
 148   <td class="unreleased" align="center">Clang 18</td>
 149  </tr>
 150  <!-- Fall 2023 papers (Kona) -->
 151  <tr>
 152   <td>Template parameter initialization</td>
 153   <td><a href="https://wg21.link/P2308R1">P2308R1</a> (<a href="#dr">DR</a>)</td>
 154   <td class="none" align="center">No</td>
 155  </tr>
 156  <tr>
 157   <td>Pack Indexing</td>
 158   <td><a href="https://wg21.link/P2662R3">P2662R3</a></td>
 159   <td class="none" align="center">No</td>
 160  </tr>
 161  <tr>
 162   <td>Remove Deprecated Arithmetic Conversion on Enumerations</td>
 163   <td><a href="https://wg21.link/P2864R2">P2864R2</a></td>
 164   <td class="none" align="center">No</td>
 165  </tr>
 166
 167 </table>
 168 </details>
 169
 170 <h2 id="cxx23">C++23 implementation status</h2>
 171
 172 <!-- TODO add link to the ISO Standard after it's published. -->
 173 <p>Clang has support for some of the features of the ISO C++ 2023 standard.</p>
 174
 175 <p>You can use Clang in C++23 mode with the <code>-std=c++23</code> option.</p>
 176
 177 <details open>
 178 <summary>List of features and minimum Clang version with support</summary>
 179
 180 <table width="689" border="1" cellspacing="0">
 181  <tr>
 182     <th>Language Feature</th>
 183     <th>C++23 Proposal</th>
 184     <th>Available in Clang?</th>
 185  </tr>
 186     <!-- Fall 2020 papers -->
 187     <tr>
 188       <td>Literal suffix <tt>uz</tt>, <tt>z</tt> for <tt>size_t</tt>, <tt>ssize_t</tt></td>
 189       <td><a href="https://wg21.link/p0330r8">P0330R8</a></td>
 190       <td class="full" align="center">Clang 13</td>
 191     </tr>
 192     <!-- Spring 2021 papers -->
 193     <tr>
 194       <td>Make <tt>()</tt> in lambdas optional in all cases</td>
 195       <td><a href="https://wg21.link/p1102r2">P1102R2</a></td>
 196       <td class="full" align="center">Clang 13</td>
 197     </tr>
 198     <tr>
 199       <td>Simpler implicit move</td>
 200       <td><a href="https://wg21.link/p2266r1">P2266R1</a></td>
 201       <td class="full" align="center">Clang 13</td>
 202     </tr>
 203     <tr>
 204       <td><tt>if consteval</tt></td>
 205       <td><a href="https://wg21.link/P1938R3">P1938R3</a></td>
 206       <td class="full" align="center">Clang 14</td>
 207     </tr>
 208     <tr>
 209       <td>Allow duplicate attributes</td>
 210       <td><a href="https://wg21.link/P2156R1">P2156R1</a></td>
 211       <td class="full" align="center">Clang 13</td>
 212     </tr>
 213     <tr>
 214       <td>Narrowing contextual conversions to bool</td>
 215       <td><a href="https://wg21.link/P1401R5">P1401R5</a></td>
 216       <td class="full" align="center">Clang 14</td>
 217     </tr>
 218     <tr>
 219       <td>Trimming whitespaces before line splicing</td>
 220       <td><a href="https://wg21.link/P2223R2">P2223R2</a></td>
 221       <td class="full" align="center">Yes</td>
 222     </tr>
 223     <tr>
 224       <td>Make declaration order layout mandated</td>
 225       <td><a href="https://wg21.link/p1847r4">P1874R4</a></td>
 226       <td class="full" align="center">Yes</td>
 227     </tr>
 228     <tr>
 229       <td>C++ identifier syntax using UAX 31</td>
 230       <td><a href="https://wg21.link/P1949R7">P1949R7</a></td>
 231       <td class="full" align="center">Clang 14</td>
 232     </tr>
 233     <tr>
 234       <td>Mixed string literal concatenation</td>
 235       <td><a href="https://wg21.link/p2201r1">P2201R1</a></td>
 236       <td class="full" align="center">Yes</td>
 237     </tr>
 238     <!-- October 2021 papers -->
 239     <tr>
 240       <td rowspan=2>Deducing this</td>
 241       <td><a href="https://wg21.link/P0847R7">P0847R7</a></td>
 242       <td class="unreleased" align="center">Clang 18</td>
 243     </tr>
 244     <tr>
 245       <td><a href="https://wg21.link/P2797R0">P2797R0</a></td>
 246       <td class="none" align="center">No</td>
 247     </tr>
 248     <tr>
 249       <td rowspan=2>Change scope of lambda trailing-return-type</td>
 250       <td><a href="https://wg21.link/P2036R3">P2036R3</a></td>
 251       <td rowspan=2 class="full" align="center">Clang 17</td>
 252     </tr>
 253     <tr>
 254       <td><a href="https://wg21.link/P2579R0">P2579R0</a></td>
 255     </tr>
 256     <tr>
 257       <td>Multidimensional subscript operator</td>
 258       <td><a href="https://wg21.link/P2128R6">P2128R6</a></td>
 259       <td class="full" align="center">Clang 15</td>
 260     </tr>
 261     <tr>
 262       <td>Non-literal variables (and labels and gotos) in constexpr functions</td>
 263       <td><a href="https://wg21.link/P2242R3">P2242R3</a></td>
 264       <td class="full" align="center">Clang 15</td>
 265     </tr>
 266     <tr>
 267       <td>Character encoding of diagnostic text</td>
 268       <td><a href="https://wg21.link/P2246R1">P2246R1</a></td>
 269       <td class="full" align="center">Yes</td>
 270     </tr>
 271     <tr>
 272       <td>Character sets and encodings</td>
 273       <td><a href="https://wg21.link/P2314R4">P2314R4</a></td>
 274       <td class="full" align="center">Yes</td>
 275     </tr>
 276     <tr>
 277       <td>Consistent character literal encoding</td>
 278       <td><a href="https://wg21.link/P2316R2">P2316R2</a></td>
 279       <td class="full" align="center">Yes</td>
 280     </tr>
 281     <tr>
 282       <td>Add support for preprocessing directives elifdef and elifndef</td>
 283       <td><a href="https://wg21.link/P2334R1">P2334R1</a></td>
 284       <td class="full" align="center">Clang 13</td>
 285     </tr>
 286     <tr>
 287       <td>Extend init-statement to allow alias-declaration</td>
 288       <td><a href="https://wg21.link/P2360R0">P2360R0</a></td>
 289       <td class="full" align="center">Clang 14</td>
 290     </tr>
 291     <tr>
 292       <td>auto(x): decay-copy in the language</td>
 293       <td><a href="https://wg21.link/P0849R8">P0849R8</a></td>
 294       <td class="full" align="center">Clang 15</td>
 295     </tr>
 296     <!-- February 2022 papers -->
 297     <tr>
 298       <td>Attributes on Lambda-Expressions</td>
 299       <td><a href="https://wg21.link/P2173R1">P2173R1</a></td>
 300       <td class="full" align="center">Clang 13</td>
 301     </tr>
 302     <tr>
 303       <td><tt>constexpr</tt> for <tt>&lt;cmath&gt;</tt> and <tt>&lt;cstdlib&gt;</tt></td>
 304       <td><a href="https://wg21.link/P0533R9">P0533R9</a></td>
 305       <td class="none" align="center">No</td>
 306     </tr>
 307     <tr>
 308       <td>Type trait to determine if a reference binds to a temporary</td>
 309       <td><a href="https://wg21.link/P2255R2">P2255R2</a></td>
 310       <td class="partial" align="center">
 311         <details><summary>Partial</summary>
 312           Clang provides <tt>__reference_constructs_from_temporary</tt> type
 313           trait builtin, with which <tt>std::reference_constructs_from_temporary</tt>
 314           is implemented. <tt>__reference_converts_from_temporary</tt> needs to be
 315           provided, following the normal cross-vendor convention to implement
 316           traits requiring compiler support directly.
 317         </details></td>
 318       </td>
 319     </tr>
 320     <!-- July 2022 papers -->
 321     <tr>
 322       <td>The Equality Operator You Are Looking For</td>
 323       <td><a href="https://wg21.link/P2468R2">P2468R2</a></td>
 324       <td class="full" align="center">Clang 16</td>
 325     </tr>
 326     <tr>
 327       <td>De-deprecating volatile compound operations</td>
 328       <td><a href="https://wg21.link/P2327R1">P2327R1</a></td>
 329       <td class="full" align="center">Clang 15</td>
 330     </tr>
 331     <tr>
 332       <td>Support for <code>#warning</code></td>
 333       <td><a href="https://wg21.link/P2437R1">P2437R1</a></td>
 334       <td class="full" align="center">Yes</td>
 335     </tr>
 336     <tr>
 337       <td>Remove non-encodable wide character literals and multicharacter wide character literals</td>
 338       <td><a href="https://wg21.link/P2362R3">P2362R3</a></td>
 339       <td class="full" align="center">Clang 14</td>
 340     </tr>
 341     <tr>
 342       <td>Labels at the end of compound statements</td>
 343       <td><a href="https://wg21.link/P2324R2">P2324R2</a></td>
 344       <td class="full" align="center">Clang 16</td>
 345     </tr>
 346     <tr>
 347       <td>Delimited escape sequences</td>
 348       <td><a href="https://wg21.link/P2290R3">P2290R3</a></td>
 349       <td class="full" align="center">Clang 15</td>
 350     </tr>
 351     <tr>
 352       <td>Named universal character escapes</td>
 353       <td><a href="https://wg21.link/P2071R2">P2071R2</a></td>
 354       <td class="full" align="center">Clang 15</td>
 355     </tr>
 356     <tr>
 357       <td>Relaxing some constexpr restrictions</td>
 358       <td><a href="https://wg21.link/P2448R2">P2448R2</a></td>
 359       <td class="partial" align="center">
 360         <details><summary>Clang 17 (Partial)</summary>
 361           We do not support outside of defaulted special memeber functions the change that constexpr functions no
 362           longer have to be constexpr compatible but rather support a less restricted requirements for constexpr
 363           functions. Which include allowing non-literal types as return values and parameters, allow calling of
 364           non-constexpr functions and constructors.
 365         </details></td>
 366       </td>
 367     </tr>
 368     <tr>
 369       <td>Using unknown pointers and references in constant expressions</td>
 370       <td><a href="https://wg21.link/P2280R4">P2280R4</a> (<a href="#dr">DR</a>)</td>
 371       <td class="none" align="center">No</td>
 372     </tr>
 373     <tr>
 374       <td>static <code>operator()</code></td>
 375       <td><a href="https://wg21.link/P1169R4">P1169R4</a></td>
 376       <td class="full" align="center">Clang 16</td>
 377     </tr>
 378     <tr>
 379       <td>Extended floating-point types and standard names</td>
 380       <td><a href="https://wg21.link/P1467R9">P1467R9</a></td>
 381       <td class="none" align="center">No</td>
 382     </tr>
 383     <tr>
 384       <td>Class template argument deduction from inherited constructors</td>
 385       <td><a href="https://wg21.link/P2582R1">P2582R1</a></td>
 386       <td class="none" align="center">No</td>
 387     </tr>
 388     <tr>
 389       <td>Portable assumptions</td>
 390       <td><a href="https://wg21.link/P1774R8">P1774R8</a></td>
 391       <td class="none" align="center">No</td>
 392     </tr>
 393     <tr>
 394       <td>Support for UTF-8 as a portable source file encoding</td>
 395       <td><a href="https://wg21.link/P2295R6">P2295R6</a></td>
 396       <td class="full" align="center">Clang 15</td>
 397     </tr>
 398     <tr>
 399       <td><code>char8_t</code> Compatibility and Portability Fix</td>
 400       <td><a href="https://wg21.link/P2513R3">P2513R3</a></td>
 401       <td class="full" align="center">Clang 16</td>
 402     </tr>
 403     <tr>
 404       <td>Relax requirements on <code>wchar_t</code> to match existing practices</td>
 405       <td><a href="https://wg21.link/P2460R2">P2460R2</a></td>
 406       <td class="full" align="center">Yes</td>
 407     </tr>
 408     <tr>
 409       <td>Explicit lifetime management</td>
 410       <td><a href="https://wg21.link/P2590R2">P2590R2</a></td>
 411       <td class="none" align="center">No</td>
 412     </tr>
 413     <!-- November 2022 (Kona) papers -->
 414     <tr>
 415       <td>static <code>operator[]</code></td>
 416       <td><a href="https://wg21.link/P2589R1">P2589R1</a></td>
 417       <td class="full" align="center">Clang 16</td>
 418     </tr>
 419     <tr>
 420       <td>Permitting static constexpr variables in constexpr functions</td>
 421       <td><a href="https://wg21.link/P2647R1">P2647R1</a></td>
 422       <td class="full" align="center">Clang 16</td>
 423     </tr>
 424     <tr>
 425       <td>consteval needs to propagate up</td>
 426       <td><a href="https://wg21.link/P2564R3">P2564R3</a> (<a href="#dr">DR</a>)</td>
 427       <td class="full" align="center">Clang 17</td>
 428     </tr>
 429     <tr>
 430       <td>Lifetime extension in range-based for loops</td>
 431       <td><a href="https://wg21.link/P2718R0">P2718R0</a></td>
 432       <td class="none" align="center">No</td>
 433     </tr>
 434     <!--Issaquah 2023 papers-->
 435     <tr>
 436       <td>Referencing The Unicode Standard</td>
 437       <td><a href="https://wg21.link/P2736R2">P2736R2</a></td>
 438       <td class="full" align="center">Yes</td>
 439     </tr>
 440 </table>
 441 </details>
 442
 443
 444 <h2 id="cxx20">C++20 implementation status</h2>
 445
 446 <p>Clang has support for some of the features of the
 447 <a href="https://www.iso.org/standard/79358.html">ISO C++ 2020 standard</a>.</p>
 448
 449 <p>You can use Clang in C++20 mode with the <code>-std=c++20</code> option
 450 (use <code>-std=c++2a</code> in Clang 9 and earlier).</p>
 451
 452 <details open>
 453 <summary>List of features and minimum Clang version with support</summary>
 454
 455 <table width="689" border="1" cellspacing="0">
 456  <tr>
 457     <th>Language Feature</th>
 458     <th>C++20 Proposal</th>
 459     <th>Available in Clang?</th>
 460  </tr>
 461     <!-- Toronto 2017 papers -->
 462     <tr>
 463       <td>Default member initializers for bit-fields</td>
 464       <td><a href="https://wg21.link/p0683r1">P0683R1</a></td>
 465       <td class="full" align="center">Clang 6</td>
 466     </tr>
 467     <tr>
 468       <td><tt>const&amp;</tt>-qualified pointers to members</td>
 469       <td><a href="https://wg21.link/p0704r1">P0704R1</a></td>
 470       <td class="full" align="center">Clang 6</td>
 471     </tr>
 472     <tr>
 473       <td>Allow <i>lambda-capture</i> <tt>[=, this]</tt></td>
 474       <td><a href="https://wg21.link/p0409r2">P0409R2</a></td>
 475       <td class="full" align="center">Clang 6</td>
 476     </tr>
 477     <tr>
 478       <td rowspan="2"><tt>__VA_OPT__</tt> for preprocessor comma elision</td>
 479       <td><a href="https://wg21.link/p0306r4">P0306R4</a></td>
 480       <td class="full" align="center">Clang 6</td>
 481     </tr>
 482       <tr> <!-- from Rapperswil -->
 483         <td><a href="https://wg21.link/p1042r1">P1042R1</a></td>
 484         <td class="full" align="center">Clang 9</td>
 485       </tr>
 486     <tr>
 487       <td>Designated initializers</td>
 488       <td><a href="https://wg21.link/p0329r4">P0329R4</a></td>
 489       <td class="full" align="center">Clang 10</td>
 490     </tr>
 491     <tr>
 492       <td><i>template-parameter-list</i> for generic lambdas</td>
 493       <td><a href="https://wg21.link/p0428r2">P0428R2</a></td>
 494       <td class="full" align="center">Clang 9</td>
 495     </tr>
 496     <tr id="p0734">
 497       <td rowspan="13">Concepts</td>
 498       <td><a href="https://wg21.link/p0734r0">P0734R0</a></td>
 499       <td class="full" align="center">Clang 10</td>
 500     </tr>
 501       <tr> <!-- from Albuquerque -->
 502         <td><a href="https://wg21.link/p0857r0">P0857R0</a></td>
 503         <td rowspan="1" class="full" align="center">Clang 16</td>
 504       </tr>
 505       <tr> <!-- from San Diego -->
 506         <td><a href="https://wg21.link/p1084r2">P1084R2</a></td>
 507         <td rowspan="2" class="full" align="center">Clang 10</td>
 508       </tr>
 509       <tr>
 510         <td><a href="https://wg21.link/p1141r2">P1141R2</a></td>
 511       </tr>
 512       <tr> <!-- from Cologne -->
 513         <td><a href="https://wg21.link/p0848r3">P0848R3</a></td>
 514         <td rowspan="1" class="partial" align="center">
 515           <details>
 516             <summary>Clang 16 (Partial)</summary>
 517             Because of other concepts implementation deficits, the __cpp_concepts macro is not yet set to 202002L.
 518             Also, the related defect reports <a href="https://wg21.link/cwg1496">DR1496</a> and
 519             <a href="https://wg21.link/cwg1734">DR1734</a> are not yet implemented. Accordingly, deleted
 520             special member functions are treated as eligible even though they shouldn't be.
 521           </details>
 522         </td>
 523         </tr>
 524       <tr>
 525         <td><a href="https://wg21.link/p1616r1">P1616R1</a></td>
 526         <td rowspan="2" class="full" align="center">Clang 10</td>
 527       </tr>
 528       <tr>
 529         <td><a href="https://wg21.link/p1452r2">P1452R2</a></td>
 530       </tr>
 531       <tr> <!-- from Belfast -->
 532         <td><a href="https://wg21.link/p1972r0">P1972R0</a></td>
 533         <td rowspan="4" class="full" align="center">Clang 10</td>
 534       </tr>
 535       <tr>
 536         <td><a href="https://wg21.link/p1980r0">P1980R0</a></td>
 537       </tr>
 538       <tr> <!-- from Prague -->
 539         <td><a href="https://wg21.link/p2103r0">P2103R0</a></td>
 540       </tr>
 541       <tr> <!-- from February 2022 -->
 542         <td><a href="https://wg21.link/p2493r0">P2493R0</a></td>
 543       </tr>
 544       <tr>
 545         <td><a href="https://wg21.link/p2092r0">P2092R0</a></td>
 546         <td rowspan="1" class="full" align="center">Clang 16</td>
 547       </tr>
 548       <tr>
 549         <td><a href="https://wg21.link/p2113r0">P2113R0</a></td>
 550         <td rowspan="1" class="full" align="center">Clang 16</td>
 551       </tr>
 552     <!-- Albuquerque papers -->
 553     <tr>
 554       <td>Range-based for statements with initializer</td>
 555       <td><a href="https://wg21.link/p0614r1">P0614R1</a></td>
 556       <td class="full" align="center">Clang 8</td>
 557     </tr>
 558     <tr>
 559       <td>ADL and function templates that are not visible</td>
 560       <td><a href="https://wg21.link/p0846r0">P0846R0</a></td>
 561       <td class="full" align="center">Clang 9</td>
 562     </tr>
 563     <tr>
 564       <td><tt>const</tt> mismatch with defaulted copy constructor</td>
 565       <td><a href="https://wg21.link/p0641r2">P0641R2</a></td>
 566       <td class="full" align="center">Clang 8</td>
 567     </tr>
 568     <tr>
 569       <td rowspan="10">Consistent comparison (<tt>operator&lt;=&gt;</tt>)</td>
 570       <td><a href="https://wg21.link/p0515r3">P0515R3</a></td>
 571       <td rowspan="8" class="full" align="center">Clang 10</td>
 572     </tr>
 573       <tr> <!-- from Jacksonville -->
 574         <td><a href="https://wg21.link/p0905r1">P0905R1</a></td>
 575       </tr>
 576       <tr> <!-- from Rapperswil -->
 577         <td><a href="https://wg21.link/p1120r0">P1120R0</a></td>
 578       </tr>
 579       <tr> <!-- from Kona 2019 -->
 580         <td><a href="https://wg21.link/p1185r2">P1185R2</a></td>
 581       </tr>
 582       <tr> <!-- from Cologne -->
 583         <td><a href="https://wg21.link/p1186r3">P1186R3</a></td>
 584       </tr>
 585       <tr>
 586         <td><a href="https://wg21.link/p1630r1">P1630R1</a></td>
 587       </tr>
 588       <tr> <!-- from Belfast -->
 589         <td><a href="https://wg21.link/p1946r0">P1946R0</a></td>
 590       </tr>
 591       <tr>
 592         <td><a href="https://wg21.link/p1959r0">P1959R0</a></td>
 593       </tr>
 594       <tr> <!-- from Prague -->
 595         <td><a href="https://wg21.link/p2002r1">P2002R1</a></td>
 596         <td class="full" align="center">Clang 17</td>
 597       </tr>
 598       <tr>
 599         <td><a href="https://wg21.link/p2085r0">P2085R0</a></td>
 600         <td class="full" align="center">Clang 14</td>
 601       </tr>
 602     <tr>
 603       <td>Access checking on specializations</td>
 604       <td><a href="https://wg21.link/p0692r1">P0692R1</a></td>
 605       <td class="full" align="center">Clang 14</td>
 606     </tr>
 607     <tr>
 608       <td>Default constructible and assignable stateless lambdas</td>
 609       <td><a href="https://wg21.link/p0624r2">P0624R2</a></td>
 610       <td class="full" align="center">Clang 8</td>
 611     </tr>
 612     <tr>
 613       <td>Lambdas in unevaluated contexts</td>
 614       <td><a href="https://wg21.link/p0315r4">P0315R4</a></td>
 615       <td class="full" align="center">Clang 17</td>
 616     </tr>
 617     <!-- Jacksonville papers -->
 618     <tr>
 619       <td><tt>[[no_unique_address]]</tt> attribute</td>
 620       <td><a href="https://wg21.link/p0840r2">P0840R2</a></td>
 621       <td class="full" align="center">Clang 9</td>
 622     </tr>
 623     <tr>
 624       <td><tt>[[likely]]</tt> and <tt>[[unlikely]]</tt> attributes</td>
 625       <td><a href="https://wg21.link/p0479r5">P0479R5</a></td>
 626       <td class="full" align="center">Clang 12</td>
 627     </tr>
 628     <tr>
 629       <td><tt>typename</tt> optional in more contexts</td>
 630       <td><a href="https://wg21.link/p0634r3">P0634R3</a></td>
 631       <td class="full" align="center">Clang 16</td>
 632     </tr>
 633     <tr>
 634       <td>Pack expansion in lambda <i>init-capture</i></td>
 635       <td><a href="https://wg21.link/p0780r2">P0780R2</a></td>
 636       <td class="full" align="center">Clang 9</td>
 637     </tr>
 638     <!-- Rapperswil papers -->
 639     <tr>
 640       <td rowspan="2">Class types as non-type template parameters</td>
 641       <td><a href="https://wg21.link/p0732r2">P0732R2</a></td>
 642       <td rowspan="2" class="partial" align="center">Partial</td>
 643     </tr>
 644       <tr> <!-- from Belfast -->
 645         <td><a href="https://wg21.link/p1907r1">P1907R1</a></td>
 646       </tr>
 647     <tr>
 648       <td>Destroying operator delete</td>
 649       <td><a href="https://wg21.link/p0722r3">P0722R3</a></td>
 650       <td class="full" align="center">Clang 6</td>
 651     </tr>
 652     <tr>
 653       <td rowspan="7">Relaxations of <tt>constexpr</tt> restrictions</td>
 654       <td><a href="https://wg21.link/p1064r0">P1064R0</a></td>
 655       <td class="full" align="center">Clang 9</td>
 656     </tr>
 657       <tr> <!-- from San Diego -->
 658         <td><a href="https://wg21.link/p1002r1">P1002R1</a></td>
 659         <td class="full" align="center">Clang 8</td>
 660       </tr>
 661       <tr>
 662         <td><a href="https://wg21.link/p1327r1">P1327R1</a></td>
 663         <td rowspan="2" class="full" align="center">Clang 9</td>
 664       </tr>
 665       <tr>
 666         <td><a href="https://wg21.link/p1330r0">P1330R0</a></td>
 667       </tr>
 668       <tr> <!-- from Cologne -->
 669         <td><a href="https://wg21.link/p1331r2">P1331R2</a></td>
 670         <td rowspan="3" class="full" align="center">Clang 10</td>
 671       </tr>
 672       <tr>
 673         <td><a href="https://wg21.link/p1668r1">P1668R1</a></td>
 674       </tr>
 675       <tr>
 676         <td><a href="https://wg21.link/p0784r7">P0784R7</a></td>
 677       </tr>
 678     <tr>
 679       <td>Prohibit aggregates with user-declared constructors</td>
 680       <td><a href="https://wg21.link/p1008r1">P1008R1</a></td>
 681       <td class="full" align="center">Clang 8</td>
 682     </tr>
 683     <tr>
 684       <td>Feature test macros</td>
 685       <td><a href="https://wg21.link/p0941r2">P0941R2</a></td>
 686       <td class="full" align="center"><a href="#sd6">(see below)</a></td>
 687     </tr>
 688     <tr>
 689       <td><tt>explicit(bool)</tt></td>
 690       <td><a href="https://wg21.link/p0892r2">P0892R2</a></td>
 691       <td class="full" align="center">Clang 9</td>
 692     </tr>
 693     <!-- San Diego papers -->
 694     <tr>
 695       <td>Signed integers are two's complement</td>
 696       <td><a href="https://wg21.link/p1236r1">P1236R1</a></td>
 697       <td class="full" align="center">Clang 9</td>
 698     </tr>
 699     <tr>
 700       <td><tt>char8_t</tt></td>
 701       <td><a href="https://wg21.link/p0482r6">P0482R6</a></td>
 702       <td class="full" align="center">Clang 7 <a href="#p0482">(11)</a></td>
 703     </tr>
 704     <tr>
 705       <td rowspan=2>Immediate functions (<tt>consteval</tt>)</td>
 706       <td><a href="https://wg21.link/p1073r3">P1073R3</a></td>
 707       <td class="full" align="center">Clang 17</td>
 708     </tr>
 709       <tr> <!-- from Prague -->
 710         <td><a href="https://wg21.link/p1937r2">P1937R2</a></td>
 711         <td class="full" align="center">Clang 14</td>
 712       </tr>
 713     <tr>
 714       <td><tt>std::is_constant_evaluated</tt></td>
 715       <td><a href="https://wg21.link/p0595r2">P0595R2</a></td>
 716       <td class="full" align="center">Clang 9</td>
 717     </tr>
 718     <tr>
 719       <td>Nested inline namespaces</td>
 720       <td><a href="https://wg21.link/p1094r2">P1094R2</a></td>
 721       <td class="full" align="center">Clang 8</td>
 722     </tr>
 723     <!-- Kona 2019 papers -->
 724     <tr>
 725       <td rowspan="2">Structured binding extensions</td>
 726       <td><a href="https://wg21.link/p1091r3">P1091R3</a></td>
 727       <td rowspan="2" class="full" align="center">Clang 16</td>
 728     </tr>
 729       <tr>
 730         <td><a href="https://wg21.link/p1381r1">P1381R1</a></td>
 731       </tr>
 732     <tr>
 733       <td rowspan="2">Stronger Unicode requirements</td>
 734       <td><a href="https://wg21.link/p1041r4">P1041R4</a></td>
 735       <td rowspan="2" class="full" align="center">Yes</td>
 736     </tr>
 737       <tr>
 738         <td><a href="https://wg21.link/p1139r2">P1139R2</a></td>
 739       </tr>
 740     <tr>
 741       <td rowspan="2">Parenthesized initialization of aggregates</td>
 742       <td><a href="https://wg21.link/p0960r3">P0960R3</a></td>
 743       <td rowspan="2" class="full" align="center">Clang 16</td>
 744     </tr>
 745       <tr> <!-- from Belfast -->
 746         <td><a href="https://wg21.link/p1975r0">P1975R0</a></td>
 747       </tr>
 748     <tr>
 749       <td rowspan="12">Modules</td>
 750       <td><a href="https://wg21.link/p1103r3">P1103R3</a></td>
 751       <td class="full" align="center">Clang 15</td>
 752     </tr>
 753       <tr> <!-- from Cologne -->
 754         <td><a href="https://wg21.link/p1766r1">P1766R1</a> (<a href="#dr">DR</a>)</td>
 755         <td class="full" align="center">Clang 11</td>
 756       </tr>
 757       <tr>
 758         <td><a href="https://wg21.link/p1811r0">P1811R0</a></td>
 759         <td class="none" align="center">No</td>
 760       </tr>
 761       <tr>
 762         <td><a href="https://wg21.link/p1703r1">P1703R1</a></td>
 763         <td class="none" align="center">Subsumed by P1857</td>
 764       </tr>
 765       <tr> <!-- from Belfast -->
 766         <td><a href="https://wg21.link/p1874r1">P1874R1</a></td>
 767         <td class="full" align="center">Clang 15</td>
 768       </tr>
 769       <tr> <!-- from Belfast -->
 770         <td><a href="https://wg21.link/p1979r0">P1979R0</a></td>
 771         <td class="none" align="center">No</td>
 772       </tr>
 773       <tr> <!-- from Prague -->
 774         <td><a href="https://wg21.link/p1779r3">P1779R3</a></td>
 775         <td class="full" align="center">Clang 15</td>
 776       </tr>
 777       <tr>
 778         <td><a href="https://wg21.link/p1857r3">P1857R3</a></td>
 779         <td class="none" align="center">No</td>
 780       </tr>
 781       <tr>
 782         <td><a href="https://wg21.link/p2115r0">P2115R0</a></td>
 783         <td class="partial" align="center">Partial</td>
 784       </tr>
 785       <tr>
 786         <td><a href="https://wg21.link/p1815r2">P1815R2</a></td>
 787         <td class="partial" align="center">Partial</td>
 788       </tr>
 789       <tr> <!-- from Kona 2022 -->
 790         <td><a href="https://wg21.link/P2615R1">P2615R1</a> (<a href="#dr">DR</a>)</td>
 791         <td class="none" align="center">No</td>
 792       </tr>
 793       <tr> <!-- from Issaquah 2023 -->
 794         <td><a href="https://wg21.link/P2788R0">P2788R0</a> (<a href="#dr">DR</a>)</td>
 795         <td class="none" align="center">No</td>
 796       </tr>
 797     <tr>
 798       <td>Coroutines</td>
 799       <td><a href="https://wg21.link/p0912r5">P0912R5</a></td>
 800       <td class="partial" align="center">
 801         <details><summary>Partial</summary>
 802           Fully supported on all targets except Windows, which
 803           still has some stability and ABI issues.
 804         </details></td>
 805     </tr>
 806     <!-- Cologne 2019 papers -->
 807     <tr>
 808       <td>Deprecate <tt>a[b,c]</tt></td>
 809       <td><a href="https://wg21.link/p1161r3">P1161R3</a></td>
 810       <td class="full" align="center">Clang 9</td>
 811     </tr>
 812     <tr>
 813       <td>Deprecate some problematic uses of <tt>volatile</tt></td>
 814       <td><a href="https://wg21.link/p1152r4">P1152R4</a></td>
 815       <td class="full" align="center">Clang 10</td>
 816     </tr>
 817     <tr>
 818       <td><tt>[[nodiscard("with reason")]]</tt></td>
 819       <td><a href="https://wg21.link/p1301r4">P1301R4</a></td>
 820       <td class="full" align="center">Clang 9</td>
 821     </tr>
 822     <tr>
 823       <td><tt>using enum</tt></td>
 824       <td><a href="https://wg21.link/p1099r5">P1099R5</a></td>
 825       <td class="full" align="center">Clang 13</td>
 826     </tr>
 827     <tr>
 828       <td rowspan=2>Class template argument deduction for aggregates</td>
 829       <td><a href="https://wg21.link/p1816r0">P1816R0</a></td>
 830       <td rowspan=2 class="full" align="center">Clang 17</td>
 831     </tr>
 832       <tr> <!-- from Prague -->
 833         <td><a href="https://wg21.link/p2082r1">P2082R1</a></td>
 834       </tr>
 835     <tr>
 836       <td>Class template argument deduction for alias templates</td>
 837       <td><a href="https://wg21.link/p1814r0">P1814R0</a></td>
 838       <td class="none" align="center">No</td>
 839     </tr>
 840     <tr>
 841       <td>Permit conversions to arrays of unknown bound</td>
 842       <td><a href="https://wg21.link/p0388r4">P0388R4</a></td>
 843       <td class="full" align="center">Clang 14</td>
 844     </tr>
 845     <tr>
 846       <td><tt>constinit</tt></td>
 847       <td><a href="https://wg21.link/p1143r2">P1143R2</a></td>
 848       <td class="full" align="center">Clang 10</td>
 849     </tr>
 850     <!-- Prague 2019 papers -->
 851     <tr>
 852       <td>Pseudo-destructors end object lifetimes</td>
 853       <td><a href="https://wg21.link/p0593r6">P0593R6</a> (<a href="#dr">DR</a>)</td>
 854       <td class="full" align="center">Clang 11</td>
 855     </tr>
 856     <tr>
 857       <td>More implicit moves</td>
 858       <td><a href="https://wg21.link/p1825r0">P1825R0</a> (<a href="#dr">DR</a>)</td>
 859       <td class="full" align="center">Clang 13</td>
 860     </tr>
 861 </table>
 862
 863 <p>
 864 <span id="p0482">(11): Prior to Clang 8, this feature is not enabled by
 865 <tt>-std=c++20</tt>, but can be enabled with <tt>-fchar8_t</tt>.
 866 </span>
 867 </p>
 868 </details>
 869
 870
 871 <h2 id="cxx17">C++17 implementation status</h2>
 872
 873 <p>Clang 5 and later implement all the features of the
 874 <a href="https://www.iso.org/standard/68564.html">ISO C++ 2017 standard</a>.</p>
 875
 876 <p>By default, Clang 16 or later builds C++ code according to the C++17 standard.
 877 You can use Clang in C++17 mode with the <code>-std=c++17</code> option
 878 (use <code>-std=c++1z</code> in Clang 4 and earlier).</p>
 879
 880 <details open>
 881 <summary>List of features and minimum Clang version with support</summary>
 882
 883 <table width="689" border="1" cellspacing="0">
 884  <tr>
 885     <th>Language Feature</th>
 886     <th>C++17 Proposal</th>
 887     <th>Available in Clang?</th>
 888  </tr>
 889     <!-- Issaquah 2014 papers -->
 890     <tr>
 891       <td><tt>static_assert</tt> with no message</td>
 892       <td><a href="https://wg21.link/n3928">N3928</a></td>
 893       <td class="full" align="center">Clang 3.5</td>
 894     </tr>
 895     <!-- Rapperswil papers -->
 896     <tr>
 897       <td>Disabling trigraph expansion by default</td>
 898       <td><a href="https://wg21.link/n4086">N4086</a></td>
 899       <td class="full" align="center">Clang 3.5</td>
 900     </tr>
 901     <tr>
 902       <td><tt>typename</tt> in a template template parameter</td>
 903       <td><a href="https://wg21.link/n4051">N4051</a></td>
 904       <td class="full" align="center">Clang 3.5</td>
 905     </tr>
 906     <tr>
 907       <td>New <tt>auto</tt> rules for direct-list-initialization
 908       <td><a href="https://wg21.link/n3922">N3922</a></td>
 909       <td class="full" align="center">Clang 3.8 <a href="#n3922">(8)</a></td>
 910     </tr>
 911     <!-- Urbana papers -->
 912     <tr>
 913       <td rowspan="2">Fold expressions</td>
 914       <td><a href="https://wg21.link/n4295">N4295</a></td>
 915       <td class="full" align="center">Clang 3.6</td>
 916     </tr>
 917       <tr> <!-- from Jacksonville -->
 918         <td><a href="https://wg21.link/p0036r0">P0036R0</a></td>
 919         <td class="full" align="center">Clang 3.9</td>
 920       </tr>
 921     <tr>
 922       <td><tt>u8</tt> character literals</td>
 923       <td><a href="https://wg21.link/n4267">N4267</a></td>
 924       <td class="full" align="center">Clang 3.6</td>
 925     </tr>
 926     <tr>
 927       <td>Nested namespace definition</td>
 928       <td><a href="https://wg21.link/n4230">N4230</a></td>
 929       <td class="full" align="center">Clang 3.6</td>
 930     </tr>
 931     <tr>
 932       <td>Attributes for namespaces and enumerators</td>
 933       <td><a href="https://wg21.link/n4266">N4266</a></td>
 934       <td class="full" align="center">Clang 3.6</td>
 935     </tr>
 936     <tr>
 937       <td>Allow constant evaluation for all non-type template arguments</td>
 938       <td><a href="https://wg21.link/n4268">N4268</a></td>
 939       <td class="full" align="center">Clang 3.6</td>
 940     </tr>
 941     <!-- Kona papers -->
 942     <tr>
 943       <td>Remove deprecated <tt>register</tt> storage class</td>
 944       <td><a href="https://wg21.link/p0001r1">P0001R1</a></td>
 945       <td class="full" align="center">Clang 3.8</td>
 946     </tr>
 947     <tr>
 948       <td>Remove deprecated <tt>bool</tt> increment</td>
 949       <td><a href="https://wg21.link/p0002r1">P0002R1</a></td>
 950       <td class="full" align="center">Clang 3.8</td>
 951     </tr>
 952     <tr>
 953       <td>Make exception specifications part of the type system</td>
 954       <td><a href="https://wg21.link/p0012r1">P0012R1</a></td>
 955       <td class="full" align="center">Clang 4</td>
 956     </tr>
 957     <tr>
 958       <td><tt>__has_include</tt> in preprocessor conditionals</td>
 959       <td><a href="https://wg21.link/p0061r1">P0061R1</a></td>
 960       <td class="full" align="center">Yes</td>
 961     </tr>
 962     <!-- Jacksonville papers -->
 963     <tr>
 964       <td><tt>[[fallthrough]]</tt> attribute</td>
 965       <td><a href="https://wg21.link/p0188r1">P0188R1</a></td>
 966       <td class="full" align="center">Clang 3.9</td>
 967     </tr>
 968     <tr>
 969       <td rowspan="2"><tt>[[nodiscard]]</tt> attribute</td>
 970       <td><a href="https://wg21.link/p0189r1">P0189R1</a></td>
 971       <td class="full" align="center">Clang 3.9</td>
 972     </tr>
 973       <tr> <!-- from Cologne 2019 -->
 974         <td><a href="https://wg21.link/p1771r1">P1771R1</a> (<a href="#dr">DR</a>)</td>
 975         <td class="full" align="center">Clang 9</td>
 976       </tr>
 977     <tr>
 978       <td><tt>[[maybe_unused]]</tt> attribute</td>
 979       <td><a href="https://wg21.link/p0212r1">P0212R1</a></td>
 980       <td class="full" align="center">Clang 3.9</td>
 981     </tr>
 982     <tr>
 983       <td>Aggregate initialization of classes with base classes</td>
 984       <td><a href="https://wg21.link/p0017r1">P0017R1</a></td>
 985       <td class="full" align="center">Clang 3.9</td>
 986     </tr>
 987     <tr>
 988       <td><tt>constexpr</tt> lambda expressions</td>
 989       <td><a href="https://wg21.link/p0170r1">P0170R1</a></td>
 990       <td class="full" align="center">Clang 5</td>
 991     </tr>
 992     <tr>
 993       <td>Differing <tt>begin</tt> and <tt>end</tt> types in range-based <tt>for</tt></td>
 994       <td><a href="https://wg21.link/p0184r0">P0184R0</a></td>
 995       <td class="full" align="center">Clang 3.9</td>
 996     </tr>
 997     <tr>
 998       <td>Lambda capture of <tt>*this</tt></td>
 999       <td><a href="https://wg21.link/p0018r3">P0018R3</a></td>
1000       <td class="full" align="center">Clang 3.9</td>
1001     </tr>
1002     <tr>
1003       <td>Direct-list-initialization of <tt>enum</tt>s</td>
1004       <td><a href="https://wg21.link/p0138r2">P0138R2</a></td>
1005       <td class="full" align="center">Clang 3.9</td>
1006     </tr>
1007     <tr>
1008       <td>Hexadecimal floating-point literals</td>
1009       <td><a href="https://wg21.link/p0245r1">P0245R1</a></td>
1010       <td class="full" align="center">Yes</td>
1011     </tr>
1012     <!-- Oulu papers -->
1013     <tr>
1014       <td>Using attribute namespaces without repetition</td>
1015       <td><a href="https://wg21.link/p0028r4">P0028R4</a></td>
1016       <td class="full" align="center">Clang 3.9</td>
1017     </tr>
1018     <tr>
1019       <td>Dynamic memory allocation for over-aligned data</td>
1020       <td><a href="https://wg21.link/p0035r4">P0035R4</a></td>
1021       <td class="full" align="center">Clang 4</td>
1022     </tr>
1023     <tr>
1024       <td rowspan="4">Template argument deduction for class templates</td>
1025       <td><a href="https://wg21.link/p0091r3">P0091R3</a></td>
1026       <td rowspan="2" class="full" align="center">Clang 5</td>
1027     </tr>
1028       <tr> <!-- from Issaquah -->
1029         <td><a href="https://wg21.link/p0512r0">P0512R0</a></td>
1030       </tr>
1031       <tr>
1032         <!-- from Kona 2017 -->
1033         <td><a href="https://wg21.link/p0620r1">P0620R0</a> (<a href="#dr">DR</a>)</td>
1034         <td class="full" align="center">Clang 7</td>
1035       </tr>
1036       <tr>
1037         <!-- from Toronto 2017 -->
1038         <td><a href="https://wg21.link/p0702r1">P0702R1</a> (<a href="#dr">DR</a>)</td>
1039         <td class="full" align="center">Clang 6</td>
1040       </tr>
1041     <tr>
1042       <td>Non-type template parameters with <tt>auto</tt> type</td>
1043       <td><a href="https://wg21.link/p0127r2">P0127R2</a></td>
1044       <td class="full" align="center">Clang 4</td>
1045     </tr>
1046     <tr>
1047       <td>Guaranteed copy elision</td>
1048       <td><a href="https://wg21.link/p0135r1">P0135R1</a></td>
1049       <td class="full" align="center">Clang 4</td>
1050     </tr>
1051     <tr>
1052       <td rowspan=2>Stricter expression evaluation order</td>
1053       <td><a href="https://wg21.link/p0145r3">P0145R3</a></td>
1054       <td class="full" align="center" rowspan=2>Clang 4 <a href="#p0145">(9)</a></td>
1055     </tr>
1056     <tr>
1057       <td><a href="https://wg21.link/p0400r0">P0400R0</a></td>
1058     </tr>
1059     <tr>
1060       <td>Requirement to ignore unknown attributes</td>
1061       <td><a href="https://wg21.link/p0283r2">P0283R2</a></td>
1062       <td class="full" align="center">Yes</td>
1063     </tr>
1064     <tr>
1065       <td><tt>constexpr</tt> <em>if-statement</em>s</td>
1066       <td><a href="https://wg21.link/p0292r2">P0292R2</a></td>
1067       <td class="full" align="center">Clang 3.9</td>
1068     </tr>
1069     <tr>
1070       <td>Inline variables</td>
1071       <td><a href="https://wg21.link/p0386r2">P0386R2</a></td>
1072       <td class="full" align="center">Clang 3.9</td>
1073     </tr>
1074     <tr>
1075       <td rowspan="3">Structured bindings</td>
1076       <td><a href="https://wg21.link/p0217r3">P0217R3</a></td>
1077       <td class="full" align="center">Clang 4</td>
1078     </tr>
1079       <tr>
1080         <!-- from Jacksonville 2018 -->
1081         <td><a href="https://wg21.link/p0961r1">P0961R1</a> (<a href="#dr">DR</a>)</td>
1082         <td class="full" align="center">Clang 8</td>
1083       </tr>
1084       <tr>
1085         <!-- from Jacksonville 2018 -->
1086         <td><a href="https://wg21.link/p0969r0">P0969R0</a> (<a href="#dr">DR</a>)</td>
1087         <td class="full" align="center">Clang 8</td>
1088       </tr>
1089     <tr>
1090       <td>Separate variable and condition for <tt>if</tt> and <tt>switch</tt></td>
1091       <td><a href="https://wg21.link/p0305r1">P0305R1</a></td>
1092       <td class="full" align="center">Clang 3.9</td>
1093     </tr>
1094     <!-- Issaquah 2016 papers -->
1095     <tr>
1096       <td>Matching template template parameters to compatible arguments</td>
1097       <td><a href="https://wg21.link/p0522r0">P0522R0</a></td>
1098       <td class="partial" align="center">Partial <a href="#p0522">(10)</a></td>
1099     </tr>
1100     <tr>
1101       <td>Removing deprecated dynamic exception specifications</td>
1102       <td><a href="https://wg21.link/p0003r5">P0003R5</a></td>
1103       <td class="full" align="center">Clang 4</td>
1104     </tr>
1105     <tr>
1106       <td>Pack expansions in <em>using-declarations</em></td>
1107       <td><a href="https://wg21.link/p0195r2">P0195R2</a></td>
1108       <td class="full" align="center">Clang 4</td>
1109     </tr>
1110 </table>
1111
1112 <p>
1113 <span id="n3922">(8): This is a backwards-incompatible change that is applied to
1114 all language versions that allow type deduction from <tt>auto</tt>
1115 (per the request of the C++ committee).
1116 In Clang 3.7, a warning is emitted for all cases that would change meaning.
1117 </span><br>
1118 <span id="p0145">(9): Under the MS ABI, function parameters are destroyed from
1119 left to right in the callee. As a result, function parameters in calls to
1120 <tt>operator&lt;&lt;</tt>, <tt>operator&gt;&gt;</tt>, <tt>operator-&gt;*</tt>,
1121 <tt>operator&amp;&amp;</tt>, <tt>operator||</tt>, and <tt>operator,</tt>
1122 functions using expression syntax are no longer guaranteed to be destroyed in
1123 reverse construction order in that ABI.
1124 This is not fully supported during constant expression evaluation until Clang 12.
1125 </span><br>
1126 <span id="p0522">(10): Despite being the resolution to a Defect Report, this
1127 feature is disabled by default in all language versions, and can be enabled
1128 explicitly with the flag <tt>-frelaxed-template-template-args</tt> in Clang 4
1129 onwards.
1130 The change to the standard lacks a corresponding change for template partial
1131 ordering, resulting in ambiguity errors for reasonable and previously-valid
1132 code. This issue is expected to be rectified soon.
1133 </span>
1134 </p>
1135 </details>
1136
1137 <h2 id="cxx14">C++14 implementation status</h2>
1138
1139 <p>Clang 3.4 and later implement all of the <a
1140     href="https://www.iso.org/standard/64029.html">ISO
1141     C++ 2014 standard</a>.</p>
1142
1143 <p>You can use Clang in C++14 mode with the <code>-std=c++14</code> option
1144 (use <code>-std=c++1y</code> in Clang 3.4 and earlier).</p>
1145
1146 <details>
1147 <summary>List of features and minimum Clang version with support</summary>
1148
1149 <table width="689" border="1" cellspacing="0">
1150  <tr>
1151     <th>Language Feature</th>
1152     <th>C++14 Proposal</th>
1153     <th>Available in Clang?</th>
1154  </tr>
1155     <tr>
1156       <td>Tweak to certain C++ contextual conversions</td>
1157       <td><a href="https://wg21.link/n3323">N3323</a></td>
1158       <td class="full" align="center">Clang 3.4</td>
1159     </tr>
1160     <tr>
1161       <td>Binary literals</td>
1162       <td><a href="https://wg21.link/n3472">N3472</a></td>
1163       <td class="full" align="center">Clang 2.9</td>
1164     </tr>
1165     <tr>
1166       <td>decltype(auto)</td>
1167       <td rowspan=2 style="vertical-align:middle"><a href="https://wg21.link/n3638">N3638</a></td>
1168       <td class="full" align="center">Clang 3.3</td>
1169     </tr>
1170     <tr>
1171       <td>Return type deduction for normal functions</td>
1172       <td class="full" align="center">Clang 3.4</td>
1173     </tr>
1174     <tr>
1175       <td>Initialized lambda captures</td>
1176       <td><a href="https://wg21.link/n3648">N3648</a></td>
1177       <td class="full" align="center">Clang 3.4</td>
1178     </tr>
1179     <tr>
1180       <td>Generic lambdas</td>
1181       <td><a href="https://wg21.link/n3649">N3649</a></td>
1182       <td class="full" align="center">Clang 3.4</td>
1183     </tr>
1184     <tr>
1185       <td>Variable templates</td>
1186       <td><a href="https://wg21.link/n3651">N3651</a></td>
1187       <td class="full" align="center">Clang 3.4</td>
1188     </tr>
1189     <tr>
1190       <td>Relaxing requirements on constexpr functions</td>
1191       <td><a href="https://wg21.link/n3652">N3652</a></td>
1192       <td class="full" align="center">Clang 3.4</td>
1193     </tr>
1194     <tr>
1195       <td>Member initializers and aggregates</td>
1196       <td><a href="https://wg21.link/n3653">N3653</a></td>
1197       <td class="full" align="center">Clang 3.3</td>
1198     </tr>
1199     <tr>
1200       <td>Clarifying memory allocation</td>
1201       <td><a href="https://wg21.link/n3664">N3664</a></td>
1202       <td class="full" align="center">Clang 3.4</td>
1203     </tr>
1204     <tr>
1205       <td><tt>[[deprecated]]</tt> attribute</td>
1206       <td><a href="https://wg21.link/n3760">N3760</a></td>
1207       <td class="full" align="center">Clang 3.4</td>
1208     </tr>
1209     <tr>
1210       <td>Single quotation mark as digit separator</td>
1211       <td><a href="https://wg21.link/n3781">N3781</a></td>
1212       <td class="full" align="center">Clang 3.4</td>
1213     </tr>
1214     <tr>
1215       <td>C++ Sized Deallocation</td>
1216       <td><a href="https://wg21.link/n3778">N3778</a></td>
1217       <td class="full" align="center">Clang 3.4 <a href="#n3778">(7)</a></td>
1218     </tr>
1219 </table>
1220
1221 <p>
1222 <span id="n3778">(7): In Clang 3.7 and later, sized deallocation is only enabled
1223 if the user passes the <code>-fsized-deallocation</code> flag. The user must
1224 supply definitions of the sized deallocation functions, either by providing them
1225 explicitly or by using a C++ standard library that does. <code>libstdc++</code>
1226 added these functions in version 5.0, and <code>libc++</code> added them in
1227 version 3.7.
1228 </span>
1229 </p>
1230 </details>
1231
1232 <h2 id="cxx11">C++11 implementation status</h2>
1233
1234 <p>Clang 3.3 and later implement all of the <a
1235   href="https://www.iso.org/standard/50372.html">ISO
1236   C++ 2011 standard</a>.</p>
1237
1238 <p>You can use Clang in C++11 mode with the <code>-std=c++11</code>
1239 option. Clang's C++11 mode can be used with
1240 <a href="https://libcxx.llvm.org/">libc++</a> or with gcc's libstdc++.</p>
1241
1242 <details>
1243 <summary>List of features and minimum Clang version with support</summary>
1244
1245 <table width="689" border="1" cellspacing="0">
1246  <tr>
1247     <th>Language Feature</th>
1248     <th>C++11 Proposal</th>
1249     <th>Available in Clang?</th>
1250  </tr>
1251      <tr>
1252       <td rowspan="2">Rvalue references</td>
1253       <td><a href="https://wg21.link/n2118">N2118</a></td>
1254       <td class="full" align="center">Clang 2.9</td>
1255       <tr> <!-- from Kona 2019-->
1256         <td><a href="https://wg21.link/p1825r0">P1825R0</a> (<a href="#dr">DR</a>)</td>
1257         <td class="full" align="center">Clang 13</td>
1258       </tr>
1259     </tr>
1260     <tr>
1261       <td>&nbsp;&nbsp;&nbsp;&nbsp;Rvalue references for <code>*this</code></td>
1262       <td><a href="https://wg21.link/n2439">N2439</a></td>
1263       <td class="full" align="center">Clang 2.9</td>
1264     </tr>
1265     <tr>
1266       <td>Initialization of class objects by rvalues</td>
1267       <td><a href="https://wg21.link/n1610">N1610</a></td>
1268       <td class="full" align="center">Clang 2.9</td>
1269     </tr>
1270     <tr>
1271       <td>Non-static data member initializers</td>
1272       <td><a href="https://wg21.link/n2756">N2756</a></td>
1273       <td class="full" align="center">Clang 3.0</td>
1274     </tr>
1275     <tr>
1276       <td>Variadic templates</td>
1277       <td><a href="https://wg21.link/n2242">N2242</a></td>
1278       <td class="full" align="center">Clang 2.9</td>
1279     </tr>
1280     <tr>
1281       <td>&nbsp;&nbsp;&nbsp;&nbsp;Extending variadic template template parameters</td>
1282       <td><a href="https://wg21.link/n2555">N2555</a></td>
1283       <td class="full" align="center">Clang 2.9</td>
1284     </tr>
1285     <tr>
1286       <td rowspan="3">Initializer lists</td>
1287       <td><a href="https://wg21.link/n2672">N2672</a></td>
1288       <td class="full" align="center">Clang 3.1</td>
1289     </tr>
1290       <tr> <!-- from Kona 2019-->
1291         <td><a href="https://wg21.link/p1009r2">P1009R2</a> (<a href="#dr">DR</a>)</td>
1292         <td class="full" align="center">Clang 9</td>
1293       </tr>
1294       <tr> <!-- from Prague-->
1295         <td><a href="https://wg21.link/p1957r2">P1957R2</a> (<a href="#dr">DR</a>)</td>
1296         <td class="full" align="center">Clang 11</td>
1297       </tr>
1298     <tr>
1299       <td>Static assertions</td>
1300       <td><a href="https://wg21.link/n1720">N1720</a></td>
1301       <td class="full" align="center">Clang 2.9</td>
1302     </tr>
1303     <tr>
1304       <td><code>auto</code>-typed variables</td>
1305       <td><a href="https://wg21.link/n1984">N1984</a></td>
1306       <td class="full" align="center">Clang 2.9</td>
1307     </tr>
1308     <tr>
1309       <td>&nbsp;&nbsp;&nbsp;&nbsp;Multi-declarator <code>auto</code></td>
1310       <td><a href="https://wg21.link/n1737">N1737</a></td>
1311       <td class="full" align="center">Clang 2.9</td>
1312     </tr>
1313     <tr>
1314       <td>&nbsp;&nbsp;&nbsp;&nbsp;Removal of auto as a storage-class specifier</td>
1315       <td><a href="https://wg21.link/n2546">N2546</a></td>
1316       <td class="full" align="center">Clang 2.9</td>
1317     </tr>
1318     <tr>
1319       <td>&nbsp;&nbsp;&nbsp;&nbsp;New function declarator syntax</td>
1320       <td><a href="https://wg21.link/n2541">N2541</a></td>
1321       <td class="full" align="center">Clang 2.9</td>
1322     </tr>
1323     <tr>
1324       <td rowspan="2">Lambda expressions</td>
1325       <td><a href="https://wg21.link/n2927">N2927</a></td>
1326       <td class="full" align="center">Clang 3.1</td>
1327     </tr>
1328       <tr>
1329         <!-- from Albuquerque 2017 -->
1330         <td><a href="https://wg21.link/p0588r1">P0588R1</a> (<a href="#dr">DR</a>)</td>
1331         <td class="none" align="center">No</td>
1332       </tr>
1333     <tr>
1334       <td>Declared type of an expression</td>
1335       <td><a href="https://wg21.link/n2343">N2343</a></td>
1336       <td class="full" align="center">Clang 2.9</td>
1337     </tr>
1338     <tr>
1339       <td>&nbsp;&nbsp;&nbsp;&nbsp;Incomplete return types</td>
1340       <td><a href="https://wg21.link/n3276">N3276</a></td>
1341       <td class="full" align="center">Clang 3.1</td>
1342     </tr>
1343     <tr>
1344       <td>Right angle brackets</td>
1345       <td><a href="https://wg21.link/n1757">N1757</a></td>
1346       <td class="full" align="center">Clang 2.9</td>
1347     </tr>
1348     <tr>
1349       <td>Default template arguments for function templates</td>
1350       <td><a href="https://wg21.link/cwg226">DR226</a></td>
1351       <td class="full" align="center">Clang 2.9</td>
1352     </tr>
1353     <tr>
1354       <td>Solving the SFINAE problem for expressions</td>
1355       <td><a href="https://wg21.link/n2634">DR339</a></td>
1356       <td class="full" align="center">Clang 2.9</td>
1357     </tr>
1358     <tr>
1359       <td>Alias templates</td>
1360       <td><a href="https://wg21.link/n2258">N2258</a></td>
1361       <td class="full" align="center">Clang 3.0</td>
1362     </tr>
1363     <tr>
1364       <td>Extern templates</td>
1365       <td><a href="https://wg21.link/n1987">N1987</a></td>
1366       <td class="full" align="center">Clang 2.9</td>
1367     </tr>
1368     <tr>
1369       <td>Null pointer constant</td>
1370       <td><a href="https://wg21.link/n2431">N2431</a></td>
1371       <td class="full" align="center">Clang 3.0</td>
1372     </tr>
1373     <tr>
1374       <td>Strongly-typed enums</td>
1375       <td><a href="https://wg21.link/n2347">N2347</a></td>
1376       <td class="full" align="center">Clang 2.9</td>
1377     </tr>
1378     <tr>
1379       <td>Forward declarations for enums</td>
1380       <td><a href="https://wg21.link/n2764">N2764</a>
1381       <br><a href="https://wg21.link/cwg1206">DR1206</a></td>
1382       <td class="full" align="center">Clang 3.1</td>
1383     </tr>
1384     <tr>
1385       <td>Standardized attribute syntax</td>
1386       <td><a href="https://wg21.link/n2761">N2761</a></td>
1387       <td class="full" align="center">Clang 3.3 <a href="#n2761">(1)</a></td>
1388     </tr>
1389     <tr>
1390       <td rowspan="2">Generalized constant expressions</td>
1391       <td><a href="https://wg21.link/n2235">N2235</a></td>
1392       <td class="full" align="center">Clang 3.1</td>
1393     </tr>
1394       <tr>
1395         <!-- from Albuquerque 2017 -->
1396         <td><a href="https://wg21.link/p0859r0">P0859R0</a> (<a href="#dr">DR</a>)</td>
1397         <td class="full" align="center">Clang 8</td>
1398       </tr>
1399     <tr>
1400       <td>Alignment support</td>
1401       <td><a href="https://wg21.link/n2341">N2341</a></td>
1402       <td class="full" align="center">Clang 3.3</td>
1403     </tr>
1404     <tr>
1405       <td>Conditionally-support behavior</td>
1406       <td><a href="https://wg21.link/n1627">N1627</a></td>
1407       <td class="full" align="center">Clang 2.9</td>
1408     </tr>
1409     <tr>
1410       <td>Changing undefined behavior into diagnosable errors</td>
1411       <td><a href="https://wg21.link/n1727">N1727</a></td>
1412       <td class="full" align="center">Clang 2.9</td>
1413     </tr>
1414     <tr>
1415       <td>Delegating constructors</td>
1416       <td><a href="https://wg21.link/n1986">N1986</a></td>
1417       <td class="full" align="center">Clang 3.0</td>
1418     </tr>
1419     <tr>
1420       <td rowspan="2">Inheriting constructors</td>
1421       <td><a href="https://wg21.link/n2540">N2540</a></td>
1422       <td class="full" align="center">Clang 3.3</td>
1423     </tr>
1424       <tr>
1425         <!-- from Kona 2015 -->
1426         <td><a href="https://wg21.link/p0136r1">P0136R1</a> (<a href="#dr">DR</a>)</td>
1427         <td class="full" align="center">Clang 3.9</td>
1428       </tr>
1429     <tr>
1430       <td>Explicit conversion operators</td>
1431       <td><a href="https://wg21.link/n2437">N2437</a></td>
1432       <td class="full" align="center">Clang 3.0</td>
1433     </tr>
1434     <tr>
1435       <td>New character types</td>
1436       <td><a href="https://wg21.link/n2249">N2249</a></td>
1437       <td class="full" align="center">Clang 2.9</td>
1438     </tr>
1439     <tr>
1440       <td>Unicode string literals</td>
1441       <td><a href="https://wg21.link/n2442">N2442</a></td>
1442       <td class="full" align="center">Clang 3.0</td>
1443     </tr>
1444     <tr>
1445       <td>Raw string literals</td>
1446       <td><a href="https://wg21.link/n2442">N2442</a></td>
1447       <td class="full" align="center">Clang 3.0</td>
1448     </tr>
1449     <tr>
1450       <td>Universal character names in literals</td>
1451       <td><a href="https://wg21.link/n2170">N2170</a></td>
1452       <td class="full" align="center">Clang 3.1</td>
1453     </tr>
1454     <tr>
1455       <td>User-defined literals</td>
1456       <td><a href="https://wg21.link/n2765">N2765</a></td>
1457       <td class="full" align="center">Clang 3.1</td>
1458     </tr>
1459     <tr>
1460       <td>Standard Layout Types</td>
1461       <td><a href="https://wg21.link/n2342">N2342</a></td>
1462       <td class="full" align="center">Clang 3.0</td>
1463     </tr>
1464     <tr>
1465       <td rowspan="2">Defaulted functions</td>
1466       <td><a href="https://wg21.link/n2346">N2346</a></td>
1467       <td class="full" align="center">Clang 3.0</td>
1468     </tr>
1469       <tr> <!-- from Kona 2019-->
1470         <td><a href="https://wg21.link/p1286r2">P1286R2</a> (<a href="#dr">DR</a>)</td>
1471         <td class="full" align="center">Clang 9</td>
1472       </tr>
1473     <tr>
1474       <td>Deleted functions</td>
1475       <td><a href="https://wg21.link/n2346">N2346</a></td>
1476       <td class="full" align="center">Clang 2.9</td>
1477     </tr>
1478     <tr>
1479       <td>Extended friend declarations</td>
1480       <td><a href="https://wg21.link/n1791">N1791</a></td>
1481       <td class="full" align="center">Clang 2.9</td>
1482     </tr>
1483     <tr>
1484       <td>Extending <code>sizeof</code></td>
1485       <td><a href="https://wg21.link/n2253">N2253</a>
1486       <br><a href="https://wg21.link/cwg850">DR850</a></td>
1487       <td class="full" align="center">Clang 3.1</td>
1488     </tr>
1489     <tr>
1490       <td>Inline namespaces</td>
1491       <td><a href="https://wg21.link/n2535">N2535</a></td>
1492       <td class="full" align="center">Clang 2.9</td>
1493     </tr>
1494     <tr>
1495       <td>Unrestricted unions</td>
1496       <td><a href="https://wg21.link/n2544">N2544</a></td>
1497       <td class="full" align="center">Clang 3.1</td>
1498     </tr>
1499     <tr>
1500       <td>Local and unnamed types as template arguments</td>
1501       <td><a href="https://wg21.link/n2657">N2657</a></td>
1502       <td class="full" align="center">Clang 2.9</td>
1503     </tr>
1504     <tr>
1505       <td rowspan="2">Range-based for</td>
1506       <td><a href="https://wg21.link/n2930">N2930</a></td>
1507       <td class="full" align="center">Clang 3.0</td>
1508     </tr>
1509       <tr>
1510         <!-- from Jacksonville 2018 -->
1511         <td><a href="https://wg21.link/p0962r1">P0962R1</a> (<a href="#dr">DR</a>)</td>
1512         <td class="full" align="center">Clang 8</td>
1513       </tr>
1514     <tr>
1515       <td>Explicit virtual overrides</td>
1516       <td><a href="https://wg21.link/n2928">N2928</a>
1517       <br><a href="https://wg21.link/n3206">N3206</a>
1518       <br><a href="https://wg21.link/n3272">N3272</a></td>
1519       <td class="full" align="center">Clang 3.0</td>
1520     </tr>
1521     <tr>
1522       <td>Minimal support for garbage collection and reachability-based leak detection</td>
1523       <td><a href="https://wg21.link/n2670">N2670</a></td>
1524       <td class="na" align="center">N/A <a href="#n2670">(2)</a></td>
1525     </tr>
1526     <tr>
1527       <td>Allowing move constructors to throw [noexcept]</td>
1528       <td><a href="https://wg21.link/n3050">N3050</a></td>
1529       <td class="full" align="center">Clang 3.0</td>
1530     </tr>
1531     <tr>
1532       <td>Defining move special member functions</td>
1533       <td><a href="https://wg21.link/n3053">N3053</a></td>
1534       <td class="full" align="center">Clang 3.0</td>
1535     </tr>
1536
1537     <tr class="separator">
1538       <th align="center" colspan="3">Concurrency</th>
1539     </tr>
1540     <tr>
1541       <td>Sequence points</td>
1542       <td><a href="https://wg21.link/n2239">N2239</a></td>
1543       <td class="full" align="center">Clang 3.3</td>
1544     </tr>
1545     <tr>
1546       <td>Atomic operations</td>
1547       <td><a href="https://wg21.link/n2427">N2427</a></td>
1548       <td class="full" align="center">Clang 3.1</td>
1549     </tr>
1550     <tr>
1551       <td>Strong Compare and Exchange</td>
1552       <td><a href="https://wg21.link/n2748">N2748</a></td>
1553       <td class="full" align="center">Clang 3.1 <a href="#n2748">(3)</a></td>
1554     </tr>
1555     <tr>
1556       <td>Bidirectional Fences</td>
1557       <td><a href="https://wg21.link/n2752">N2752</a></td>
1558       <td class="full" align="center">Clang 3.1</td>
1559     </tr>
1560
1561     <tr>
1562       <td>Memory model</td>
1563       <td><a href="https://wg21.link/n2429">N2429</a></td>
1564       <td class="full" align="center">Clang 3.2</td>
1565     </tr>
1566     <tr>
1567       <td>Data-dependency ordering: atomics and memory model</td>
1568       <td><a href="https://wg21.link/n2664">N2664</a></td>
1569       <td class="full" align="center">Clang 3.2 <a href="#n2664">(4)</a></td>
1570     </tr>
1571     <tr>
1572       <td>Propagating exceptions</td>
1573       <td><a href="https://wg21.link/n2179">N2179</a></td>
1574       <td class="full" align="center">Clang 2.9</td>
1575     </tr>
1576     <tr>
1577       <td>Allow atomics use in signal handlers</td>
1578       <td><a href="https://wg21.link/n2547">N2547</a></td>
1579       <td class="full" align="center">Clang 3.1</td>
1580     </tr>
1581     <tr>
1582       <td>Thread-local storage</td>
1583       <td><a href="https://wg21.link/n2659">N2659</a></td>
1584       <td class="full" align="center">Clang 3.3 <a href="#n2659">(5)</a></td>
1585     </tr>
1586     <tr>
1587       <td>Dynamic initialization and destruction with concurrency</td>
1588       <td><a href="https://wg21.link/n2660">N2660</a></td>
1589       <td class="full" align="center">Clang 2.9</td>
1590     </tr>
1591
1592     <tr class="separator">
1593       <th align="center" colspan="3">C99 Features in C++11</th>
1594     </tr>
1595     <tr>
1596       <td><code>__func__</code> predefined identifier</td>
1597       <td><a href="https://wg21.link/n2340">N2340</a></td>
1598       <td class="full" align="center">Clang 2.9</td>
1599     </tr>
1600     <tr>
1601       <td>C99 preprocessor</td>
1602       <td><a href="https://wg21.link/n1653">N1653</a></td>
1603       <td class="full" align="center">Clang 2.9</td>
1604     </tr>
1605     <tr>
1606       <td><code>long long</code></td>
1607       <td><a href="https://wg21.link/n1811">N1811</a></td>
1608       <td class="full" align="center">Clang 2.9</td>
1609     </tr>
1610     <tr>
1611       <td>Extended integral types</td>
1612       <td><a href="https://wg21.link/n1988">N1988</a></td>
1613       <td class="na" align="center">N/A <a href="#n1988">(6)</a></td>
1614     </tr>
1615 </table>
1616
1617 <p>
1618 <span id="n2761">(1): The <code>[[carries_dependency]]</code> attribute
1619 has no effect.</span><br>
1620 <span id="n2670">(2): No compiler changes are required for an implementation
1621 such as Clang that does not provide garbage collection.</span><br>
1622 <span id="n2748">(3): All compare-exchange operations are emitted as
1623 strong compare-exchanges.</span><br>
1624 <span id="n2664">(4): <code>memory_order_consume</code> is lowered to
1625 <code>memory_order_acquire</code>.</span><br>
1626 <span id="n2659">(5): <code>thread_local</code> support
1627 requires a C++ runtime library providing <code>__cxa_thread_atexit</code>, such
1628 as <a href="https://libcxxabi.llvm.org">libc++abi</a> 3.6 or later,
1629 or libsupc++ 4.8 or later.</span><br>
1630 <span id="n1988">(6): No compiler changes are required for an implementation
1631 such as Clang that does not provide any extended integer types.
1632 <code>__int128</code> is not treated as an extended integer type,
1633 because changing <code>intmax_t</code> would be an ABI-incompatible
1634 change.</span>
1635 </p>
1636 </details>
1637
1638
1639 <h2 id="cxx98">C++98 implementation status</h2>
1640
1641 <p>Clang implements all of the ISO C++ 1998 standard
1642   (including the defects addressed in the ISO C++ 2003 standard)
1643   except for <tt>export</tt> (which was removed in C++11).
1644
1645 <h2 id="dr">Defect reports</h2>
1646
1647 <p>Clang generally aims to implement resolutions to Defect Reports (bug fixes
1648 against prior standards) retroactively, in all prior standard versions where
1649 the fix is meaningful. Significant Defect Report changes to language features
1650 after the publication of the relevant standard are marked (DR) in the above
1651 table.</p>
1652
1653 <p>Clang also has a test suite for conformance to resolutions for issues on the
1654 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_toc.html">C++ core issues list</a>,
1655 most of which are considered Defect Reports.
1656 <a href="cxx_dr_status.html">Implementation status for C++ core issues</a> based on
1657 that test suite is tracked on a separate page.</p>
1658
1659 <h2 id="ts">Technical specifications and standing documents</h2>
1660
1661 <p>ISO C++ also publishes a number of documents describing additional language
1662 and library features that are not part of standard C++.</p>
1663
1664 <details open>
1665 <summary>List of features and minimum Clang version with support</summary>
1666
1667 <table width="689" border="1" cellspacing="0">
1668  <tr>
1669     <th>Document</th>
1670     <th>Latest draft</th>
1671     <th>Compiler flag</th>
1672     <th>Available in Clang?</th>
1673  </tr>
1674     <tr id="sd6">
1675       <td rowspan="7">SD-6: SG10 feature test recommendations</td>
1676       <td rowspan="7"><a href="https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations">SD-6</a></td>
1677       <td rowspan="7">N/A</td>
1678       <td class="full" align="center">
1679         Clang 3.4 (<a href="https://wg21.link/n3745">N3745</a>)</br>
1680       </td>
1681     </tr>
1682     <tr>
1683       <td class="full" align="center">
1684         Clang 3.6 (<a href="https://wg21.link/n4200">N4200</a>)</a>
1685       </td>
1686     </tr>
1687     <tr>
1688       <td class="full" align="center">
1689         Clang 4 (<a href="https://wg21.link/p0096r3">P0096R3</a>)</a>
1690       </td>
1691     </tr>
1692     <tr>
1693       <td class="full" align="center">
1694         Clang 5 (<a href="https://wg21.link/p0096r4">P0096R4</a>)</a>
1695       </td>
1696     </tr>
1697     <tr>
1698       <td class="full" align="center">
1699         Clang 7 (<a href="https://wg21.link/p0096r5">P0096R5</a>)</a>
1700       </td>
1701     </tr>
1702     <tr>
1703       <td class="full" align="center">
1704         Clang 9 (<a href="https://wg21.link/p1353r0">P1353R0</a>)
1705       </td>
1706     </tr>
1707     <tr>
1708       <td class="full" align="center">
1709         Clang 10 (<a href="https://wg21.link/p1902r1">P1902R1</a>)</a>
1710       </td>
1711     </tr>
1712     <!-- No compiler support is known to be needed for:
1713            * Concurrency TS
1714            * Parallelism TS (v1, v2)
1715            * Ranges TS
1716            * Networking TS
1717            * File System TS
1718     -->
1719     <tr>
1720       <td>[TS] Concepts</td>
1721       <td><a href="https://wg21.link/p0121r0">P0121R0</a></td>
1722       <td></td>
1723       <td class="na" align="center">Superseded by <a href="#p0734">P0734R0</a></td>
1724     </tr>
1725     <tr>
1726       <!-- track unimplemented Coroutines features: p0913r1 p0914r1 p1356r0 -->
1727       <td rowspan="2">[TS] Coroutines</td>
1728       <td rowspan="2"><a href="https://isocpp.org/files/papers/N4663.pdf">N4663</a></td>
1729       <td><tt>-fcoroutines-ts<br>-stdlib=libc++</tt></td>
1730       <td class="full" align="center">Clang 5</td>
1731     </tr>
1732     <tr>
1733       <td><tt>-std=c++20<br>-stdlib=libc++</tt></td>
1734       <td class="na" align="center">Superseded by <a href="#p0912">P0912R5</a></td>
1735     </tr>
1736     <tr>
1737       <td>[TS] Library Fundamentals, Version 1 (invocation type traits)</td>
1738       <td><a href="https://wg21.link/n4480">N4480</a></td>
1739       <td>N/A</td>
1740       <td class="none" align="center">No</td>
1741     </tr>
1742     <tr>
1743       <td>[TS] Library Fundamentals, Version 2 (<tt>source_location</tt>)</td>
1744      <td><a href="https://wg21.link/n4617">N4617</a></td>
1745       <td>N/A</td>
1746       <td class="full" align="center">Clang 9 (<a href="docs/LanguageExtensions.html#source-location-builtins">documentation</a>)</td>
1747     </tr>
1748     <tr>
1749       <td>[TS] Modules</td>
1750       <td><a href="https://wg21.link/n4720">N4720</a></td>
1751       <td><tt>-fmodules-ts</tt></td>
1752       <td class="na" align="center">Superseded by <a href="#p1103">P1103R3</a></td>
1753     </tr>
1754     <tr>
1755       <td>[DRAFT TS] Reflection</td>
1756       <td><a href="https://wg21.link/n4818">N4818</a></td>
1757       <td></td>
1758       <td class="none" align="center">No</td>
1759     </tr>
1760     <tr>
1761       <td>[TS] Transactional Memory</td>
1762       <td><a href="https://wg21.link/n4514">N4514</a></td>
1763       <td></td>
1764       <td class="none" align="center">No</td>
1765     </tr>
1766 </table>
1767 </details>
1768
1769 </div>
1770 </body>
1771 </html>