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

   1 <section xmlns="http://docbook.org/ns/docbook" version="5.0"
   2          xml:id="appendix.porting.api" xreflabel="api">
   3 <?dbhtml filename="api.html"?>
   4
   5 <info><title>API Evolution and Deprecation History</title>
   6   <keywordset>
   7     <keyword>ISO C++</keyword>
   8     <keyword>api</keyword>
   9     <keyword>evolution</keyword>
  10     <keyword>deprecation</keyword>
  11     <keyword>history</keyword>
  12   </keywordset>
  13 </info>
  14
  15
  16
  17 <para>
  18 A list of user-visible changes, in chronological order
  19 </para>
  20
  21 <section xml:id="api.rel_300"><info><title><constant>3.0</constant></title></info>
  22
  23
  24   <para>
  25 Extensions moved to <filename class="directory">include/ext</filename>.
  26   </para>
  27
  28 <para>
  29 Include files from the SGI/HP sources that pre-date the ISO standard
  30 are added. These files are placed into
  31 the <filename class="directory">include/backward</filename> directory and a deprecated warning
  32 is added that notifies on inclusion (<literal>-Wno-deprecated</literal>
  33 deactivates the warning.)
  34 </para>
  35
  36 <para>Deprecated include <filename class="headerfile">backward/strstream</filename> added.</para>
  37
  38 <para>Removal of include <filename class="headerfile">builtinbuf.h</filename>, <filename class="headerfile">indstream.h</filename>, <filename class="headerfile">parsestream.h</filename>, <filename class="headerfile">PlotFile.h</filename>, <filename class="headerfile">SFile.h</filename>, <filename class="headerfile">stdiostream.h</filename>, and <filename class="headerfile">stream.h</filename>.
  39 </para>
  40
  41
  42
  43 </section>
  44
  45 <section xml:id="api.rel_310"><info><title><constant>3.1</constant></title></info>
  46
  47   <para>
  48   </para>
  49
  50 <para>
  51 Extensions from SGI/HP moved from <code>namespace std</code>
  52 to <code>namespace __gnu_cxx</code>. As part of this, the following
  53 new includes are
  54 added: <filename class="headerfile">ext/algorithm</filename>, <filename class="headerfile">ext/functional</filename>, <filename class="headerfile">ext/iterator</filename>, <filename class="headerfile">ext/memory</filename>, and <filename class="headerfile">ext/numeric</filename>.
  55 </para>
  56
  57 <para>
  58 Extensions to <code>basic_filebuf</code> introduced: <code>__gnu_cxx::enc_filebuf</code>, and <code>__gnu_cxx::stdio_filebuf</code>.
  59 </para>
  60
  61 <para>
  62 Extensions to tree data structures added in <filename class="headerfile">ext/rb_tree</filename>.
  63 </para>
  64
  65 <para>
  66 Removal of <filename class="headerfile">ext/tree</filename>, moved to <filename class="headerfile">backward/tree.h</filename>.
  67 </para>
  68
  69 </section>
  70
  71 <section xml:id="api.rel_320"><info><title><constant>3.2</constant></title></info>
  72
  73   <para>
  74   </para>
  75 <para>Symbol versioning introduced for shared library.</para>
  76
  77 <para>Removal of include <filename class="headerfile">backward/strstream.h</filename>.</para>
  78
  79 <para>Allocator changes. Change <code>__malloc_alloc</code> to <code>malloc_allocator</code> and <code>__new_alloc</code> to <code>new_allocator</code>. </para>
  80
  81    <para> For GCC releases from 2.95 through the 3.1 series, defining
  82    <literal>__USE_MALLOC</literal> on the gcc command line would change the
  83    default allocation strategy to instead use <code> malloc</code> and
  84    <function>free</function>. For the 3.2 and 3.3 release series the same
  85    functionality was spelled <literal>_GLIBCXX_FORCE_NEW</literal>. From
  86    GCC 3.4 onwards the functionality is enabled by setting
  87    <literal>GLIBCXX_FORCE_NEW</literal> in the environment, see
  88    <link linkend="manual.ext.allocator.mt">the mt allocator chapter</link>
  89    for details.
  90    </para>
  91
  92
  93 <para>Error handling in iostreams cleaned up, made consistent. </para>
  94
  95
  96 </section>
  97
  98 <section xml:id="api.rel_330"><info><title><constant>3.3</constant></title></info>
  99
 100   <para>
 101   </para>
 102 </section>
 103
 104 <section xml:id="api.rel_340"><info><title><constant>3.4</constant></title></info>
 105
 106   <para>
 107   </para>
 108 <para>
 109 Large file support.
 110 </para>
 111
 112 <para> Extensions for generic characters and <code>char_traits</code> added in <filename class="headerfile">ext/pod_char_traits.h</filename>.
 113 </para>
 114
 115 <para>
 116 Support for <code>wchar_t</code> specializations of <code>basic_filebuf</code> enhanced to support <code>UTF-8</code> and <code>Unicode</code>, depending on host. More hosts support basic <code>wchar_t</code> functionality.
 117 </para>
 118
 119 <para>
 120 Support for <code>char_traits</code> beyond builtin types.
 121 </para>
 122
 123 <para>
 124 Conformant <code>allocator</code> class and usage in containers. As
 125 part of this, the following extensions are
 126 added: <filename class="headerfile">ext/bitmap_allocator.h</filename>, <filename class="headerfile">ext/debug_allocator.h</filename>, <filename class="headerfile">ext/mt_allocator.h</filename>, <filename class="headerfile">ext/malloc_allocator.h</filename>,<filename class="headerfile">ext/new_allocator.h</filename>, <filename class="headerfile">ext/pool_allocator.h</filename>.
 127 </para>
 128
 129 <para>
 130 This is a change from all previous versions, and may require
 131 source-level changes due to allocator-related changes to structures
 132 names and template parameters, filenames, and file locations. Some,
 133 like <code>__simple_alloc, __allocator, __alloc, </code> and <code>
 134 _Alloc_traits</code> have been removed.
 135 </para>
 136
 137 <para>Default behavior of <code>std::allocator</code> has changed.</para>
 138
 139 <para>
 140    Previous versions prior to 3.4 cache allocations in a memory
 141    pool, instead of passing through to call the global allocation
 142    operators (i.e., <classname>__gnu_cxx::pool_allocator</classname>).  More
 143    recent versions default to the
 144    simpler <classname>__gnu_cxx::new_allocator</classname>.
 145 </para>
 146
 147 <para> Previously, all allocators were written to the SGI
 148    style, and all STL containers expected this interface. This
 149    interface had a traits class called <code>_Alloc_traits</code> that
 150    attempted to provide more information for compile-time allocation
 151    selection and optimization. This traits class had another allocator
 152    wrapper, <code>__simple_alloc&lt;T,A&gt;</code>, which was a
 153    wrapper around another allocator, A, which itself is an allocator
 154    for instances of T. But wait, there's more:
 155    <code>__allocator&lt;T,A&gt;</code> is another adapter.  Many of
 156    the provided allocator classes were SGI style: such classes can be
 157    changed to a conforming interface with this wrapper:
 158    <code>__allocator&lt;T, __alloc&gt;</code> is thus the same as
 159    <code>allocator&lt;T&gt;</code>.
 160    </para>
 161
 162    <para> The class <classname>allocator</classname> used the typedef
 163    <type>__alloc</type> to select an underlying allocator that
 164    satisfied memory allocation requests. The selection of this
 165    underlying allocator was not user-configurable.
 166    </para>
 167
 168 <table frame="all" xml:id="table.extension_allocators">
 169 <title>Extension Allocators</title>
 170
 171 <tgroup cols="4" align="left" colsep="1" rowsep="1">
 172 <colspec colname="c1"/>
 173 <colspec colname="c2"/>
 174 <colspec colname="c3"/>
 175 <colspec colname="c4"/>
 176
 177   <thead>
 178     <row>
 179       <entry>Allocator (3.4)</entry>
 180       <entry>Header (3.4)</entry>
 181       <entry>Allocator (3.[0-3])</entry>
 182       <entry>Header (3.[0-3])</entry>
 183     </row>
 184   </thead>
 185
 186   <tbody>
 187   <row>
 188     <entry><classname>__gnu_cxx::new_allocator&lt;T&gt;</classname></entry>
 189     <entry><filename class="headerfile">ext/new_allocator.h</filename></entry>
 190     <entry><classname>std::__new_alloc</classname></entry>
 191     <entry><filename class="headerfile">memory</filename></entry>
 192   </row>
 193   <row>
 194     <entry><classname>__gnu_cxx::malloc_allocator&lt;T&gt;</classname></entry>
 195     <entry><filename class="headerfile">ext/malloc_allocator.h</filename></entry>
 196     <entry><classname>std::__malloc_alloc_template&lt;int&gt;</classname></entry>
 197     <entry><filename class="headerfile">memory</filename></entry>
 198   </row>
 199   <row>
 200     <entry><classname>__gnu_cxx::debug_allocator&lt;T&gt;</classname></entry>
 201     <entry><filename class="headerfile">ext/debug_allocator.h</filename></entry>
 202     <entry><classname>std::debug_alloc&lt;T&gt;</classname></entry>
 203     <entry><filename class="headerfile">memory</filename></entry>
 204   </row>
 205   <row>
 206     <entry><classname>__gnu_cxx::__pool_alloc&lt;T&gt;</classname></entry>
 207     <entry><filename class="headerfile">ext/pool_allocator.h</filename></entry>
 208     <entry><classname>std::__default_alloc_template&lt;bool,int&gt;</classname></entry>
 209     <entry><filename class="headerfile">memory</filename></entry>
 210   </row>
 211   <row>
 212     <entry><classname>__gnu_cxx::__mt_alloc&lt;T&gt;</classname></entry>
 213     <entry><filename class="headerfile">ext/mt_allocator.h</filename></entry>
 214     <entry> </entry>
 215     <entry> </entry>
 216   </row>
 217   <row>
 218     <entry><classname>__gnu_cxx::bitmap_allocator&lt;T&gt;</classname></entry>
 219     <entry><filename class="headerfile">ext/bitmap_allocator.h</filename></entry>
 220     <entry> </entry>
 221     <entry> </entry>
 222   </row>
 223   </tbody>
 224 </tgroup>
 225 </table>
 226
 227    <para> Releases after gcc-3.4 have continued to add to the collection
 228    of available allocators. All of these new allocators are
 229    standard-style. The following table includes details, along with
 230    the first released version of GCC that included the extension allocator.
 231    </para>
 232
 233 <table frame="all" xml:id="table.extension_allocators2">
 234 <title>Extension Allocators Continued</title>
 235
 236 <tgroup cols="3" align="left" colsep="1" rowsep="1">
 237 <colspec colname="c1"/>
 238 <colspec colname="c2"/>
 239 <colspec colname="c3"/>
 240
 241 <thead>
 242   <row>
 243     <entry>Allocator</entry>
 244     <entry>Include</entry>
 245     <entry>Version</entry>
 246   </row>
 247 </thead>
 248
 249 <tbody>
 250   <row>
 251     <entry><classname>__gnu_cxx::array_allocator&lt;T&gt;</classname></entry>
 252     <entry><filename class="headerfile">ext/array_allocator.h</filename></entry>
 253     <entry>4.0.0</entry>
 254   </row>
 255   <row>
 256     <entry><classname>__gnu_cxx::throw_allocator&lt;T&gt;</classname></entry>
 257     <entry><filename class="headerfile">ext/throw_allocator.h</filename></entry>
 258     <entry>4.2.0</entry>
 259   </row>
 260 </tbody>
 261 </tgroup>
 262 </table>
 263
 264
 265 <para>
 266 Debug mode first appears.
 267 </para>
 268
 269 <para>
 270 Precompiled header support <acronym>PCH</acronym> support.
 271 </para>
 272
 273 <para>
 274 Macro guard for changed, from <literal>_GLIBCPP_</literal> to <literal>_GLIBCXX_</literal>.
 275 </para>
 276
 277 <para>
 278 Extension <filename class="headerfile">ext/stdio_sync_filebuf.h</filename> added.
 279 </para>
 280
 281 <para>
 282 Extension <filename class="headerfile">ext/demangle.h</filename> added.
 283 </para>
 284
 285
 286 </section>
 287
 288 <section xml:id="api.rel_400"><info><title><constant>4.0</constant></title></info>
 289
 290   <para>
 291   </para>
 292 <para>
 293 TR1 features first appear.
 294 </para>
 295
 296 <para>
 297 Extension allocator <filename class="headerfile">ext/array_allocator.h</filename> added.
 298 </para>
 299
 300 <para>
 301 Extension <code>codecvt</code> specializations moved to <filename class="headerfile">ext/codecvt_specializations.h</filename>.
 302 </para>
 303
 304 <para>
 305 Removal of <filename class="headerfile">ext/demangle.h</filename>.
 306 </para>
 307
 308
 309 </section>
 310
 311 <section xml:id="api.rel_410"><info><title><constant>4.1</constant></title></info>
 312
 313   <para>
 314   </para>
 315
 316
 317 <para>
 318 Removal of <filename class="headerfile">cassert</filename> from all standard headers: now has to be explicitly included for <code>std::assert</code> calls.
 319 </para>
 320
 321 <para> Extensions for policy-based data structures first added. New includes,
 322 types, namespace <code>pb_assoc</code>.
 323 </para>
 324
 325
 326
 327 <para> Extensions for typelists added in <filename class="headerfile">ext/typelist.h</filename>.
 328 </para>
 329
 330 <para> Extension for policy-based <code>basic_string</code> first added: <code>__gnu_cxx::__versa_string</code> in <filename class="headerfile">ext/vstring.h</filename>.
 331 </para>
 332
 333 </section>
 334
 335 <section xml:id="api.rel_420"><info><title><constant>4.2</constant></title></info>
 336
 337   <para>
 338   </para>
 339
 340
 341 <para> Default visibility attributes applied to <code>namespace std</code>. Support for <code>-fvisibility</code>.
 342 </para>
 343
 344 <para>TR1 <filename class="headerfile">random</filename>, <filename class="headerfile">complex</filename>, and C compatibility headers added.</para>
 345
 346 <para> Extensions for concurrent programming consolidated
 347 into <filename class="headerfile">ext/concurrence.h</filename> and <filename class="headerfile">ext/atomicity.h</filename>,
 348 including change of namespace to <code>__gnu_cxx</code> in some
 349 cases. Added types
 350 include <code>_Lock_policy</code>, <code>__concurrence_lock_error</code>, <code>__concurrence_unlock_error</code>, <code>__mutex</code>, <code>__scoped_lock</code>.</para>
 351
 352 <para> Extensions for type traits consolidated
 353 into <filename class="headerfile">ext/type_traits.h</filename>. Additional traits are added
 354 (<code>__conditional_type</code>, <code>__enable_if</code>, others.)
 355 </para>
 356
 357 <para> Extensions for policy-based data structures revised. New includes,
 358 types, namespace moved to <code>__pb_ds</code>.
 359 </para>
 360
 361 <para> Extensions for debug mode modified: now nested in <code>namespace
 362 std::__debug</code> and extensions in <code>namespace
 363 __gnu_cxx::__debug</code>.</para>
 364
 365 <para> Extensions added: <filename class="headerfile">ext/typelist.h</filename>
 366 and <filename class="headerfile">ext/throw_allocator.h</filename>.
 367 </para>
 368
 369 </section>
 370
 371 <section xml:id="api.rel_430"><info><title><constant>4.3</constant></title></info>
 372
 373   <para>
 374   </para>
 375
 376
 377 <para>
 378 C++0X features first appear.
 379 </para>
 380
 381 <para>TR1 <filename class="headerfile">regex</filename> and <filename class="headerfile">cmath</filename>'s mathematical special function added.
 382 </para>
 383
 384 <para>
 385 Backward include edit.
 386 </para>
 387 <itemizedlist>
 388   <listitem>
 389     <para>Removed</para>
 390   <para>
 391 <filename class="headerfile">algobase.h</filename> <filename class="headerfile">algo.h</filename> <filename class="headerfile">alloc.h</filename> <filename class="headerfile">bvector.h</filename> <filename class="headerfile">complex.h</filename>
 392 <filename class="headerfile">defalloc.h</filename> <filename class="headerfile">deque.h</filename> <filename class="headerfile">fstream.h</filename> <filename class="headerfile">function.h</filename> <filename class="headerfile">hash_map.h</filename> <filename class="headerfile">hash_set.h</filename>
 393 <filename class="headerfile">hashtable.h</filename> <filename class="headerfile">heap.h</filename> <filename class="headerfile">iomanip.h</filename> <filename class="headerfile">iostream.h</filename> <filename class="headerfile">istream.h</filename> <filename class="headerfile">iterator.h</filename>
 394 <filename class="headerfile">list.h</filename> <filename class="headerfile">map.h</filename> <filename class="headerfile">multimap.h</filename> <filename class="headerfile">multiset.h</filename> <filename class="headerfile">new.h</filename> <filename class="headerfile">ostream.h</filename> <filename class="headerfile">pair.h</filename> <filename class="headerfile">queue.h</filename> <filename class="headerfile">rope.h</filename> <filename class="headerfile">set.h</filename> <filename class="headerfile">slist.h</filename> <filename class="headerfile">stack.h</filename> <filename class="headerfile">streambuf.h</filename> <filename class="headerfile">stream.h</filename> <filename class="headerfile">tempbuf.h</filename>
 395 <filename class="headerfile">tree.h</filename> <filename class="headerfile">vector.h</filename>
 396   </para>
 397   </listitem>
 398   <listitem>
 399     <para>Added</para>
 400   <para>
 401   <filename class="headerfile">hash_map</filename> and <filename class="headerfile">hash_set</filename>
 402   </para>
 403   </listitem>
 404   <listitem>
 405     <para>Added in C++11</para>
 406   <para>
 407     <filename class="headerfile">auto_ptr.h</filename> and <filename class="headerfile">binders.h</filename>
 408   </para>
 409   </listitem>
 410
 411 </itemizedlist>
 412
 413 <para>
 414 Header dependency streamlining.
 415 </para>
 416
 417 <itemizedlist>
 418   <listitem><para><filename class="headerfile">algorithm</filename> no longer includes <filename class="headerfile">climits</filename>, <filename class="headerfile">cstring</filename>, or <filename class="headerfile">iosfwd</filename> </para></listitem>
 419   <listitem><para><filename class="headerfile">bitset</filename> no longer includes <filename class="headerfile">istream</filename> or <filename class="headerfile">ostream</filename>, adds <filename class="headerfile">iosfwd</filename> </para></listitem>
 420   <listitem><para><filename class="headerfile">functional</filename> no longer includes <filename class="headerfile">cstddef</filename></para></listitem>
 421   <listitem><para><filename class="headerfile">iomanip</filename> no longer includes <filename class="headerfile">istream</filename>, <filename class="headerfile">istream</filename>, or <filename class="headerfile">functional</filename>, adds <filename class="headerfile">ioswd</filename> </para></listitem>
 422   <listitem><para><filename class="headerfile">numeric</filename> no longer includes <filename class="headerfile">iterator</filename></para></listitem>
 423   <listitem><para><filename class="headerfile">string</filename> no longer includes <filename class="headerfile">algorithm</filename> or <filename class="headerfile">memory</filename></para></listitem>
 424
 425   <listitem><para><filename class="headerfile">valarray</filename> no longer includes <filename class="headerfile">numeric</filename> or <filename class="headerfile">cstdlib</filename></para></listitem>
 426   <listitem><para><filename class="headerfile">tr1/hashtable</filename> no longer includes <filename class="headerfile">memory</filename> or <filename class="headerfile">functional</filename></para></listitem>
 427   <listitem><para><filename class="headerfile">tr1/memory</filename> no longer includes <filename class="headerfile">algorithm</filename></para></listitem>
 428   <listitem><para><filename class="headerfile">tr1/random</filename> no longer includes <filename class="headerfile">algorithm</filename> or <filename class="headerfile">fstream</filename></para></listitem>
 429 </itemizedlist>
 430
 431 <para>
 432 Debug mode for <filename class="headerfile">unordered_map</filename> and <filename class="headerfile">unordered_set</filename>.
 433 </para>
 434
 435 <para>
 436 Parallel mode first appears.
 437 </para>
 438
 439 <para>Variadic template implementations of items in <filename class="headerfile">tuple</filename> and
 440     <filename class="headerfile">functional</filename>.
 441 </para>
 442
 443 <para>Default <code>what</code> implementations give more elaborate
 444     exception strings for <code>bad_cast</code>,
 445     <code>bad_typeid</code>, <code>bad_exception</code>, and
 446     <code>bad_alloc</code>.
 447 </para>
 448
 449 <para>
 450 PCH binary files no longer installed. Instead, the source files are installed.
 451 </para>
 452
 453 <para>
 454 Namespace pb_ds moved to __gnu_pb_ds.
 455 </para>
 456
 457 </section>
 458
 459
 460 <section xml:id="api.rel_440"><info><title><constant>4.4</constant></title></info>
 461
 462   <para>
 463   </para>
 464
 465 <para>
 466 C++0X features.
 467 </para>
 468
 469 <itemizedlist>
 470 <listitem>
 471   <para>
 472     Added.
 473   </para>
 474   <para>
 475     <filename class="headerfile">atomic</filename>,
 476     <filename class="headerfile">chrono</filename>,
 477     <filename class="headerfile">condition_variable</filename>,
 478     <filename class="headerfile">forward_list</filename>,
 479     <filename class="headerfile">initializer_list</filename>,
 480     <filename class="headerfile">mutex</filename>,
 481     <filename class="headerfile">ratio</filename>,
 482     <filename class="headerfile">thread</filename>
 483   </para>
 484 </listitem>
 485
 486 <listitem>
 487   <para>
 488     Updated and improved.
 489   </para>
 490   <para>
 491     <filename class="headerfile">algorithm</filename>,
 492     <filename class="headerfile">system_error</filename>,
 493     <filename class="headerfile">type_traits</filename>
 494   </para>
 495 </listitem>
 496
 497 <listitem>
 498   <para>
 499     Use of the GNU extension namespace association converted to inline namespaces.
 500   </para>
 501 </listitem>
 502
 503 <listitem>
 504   <para>
 505     Preliminary support for <classname>initializer_list</classname>
 506     and defaulted and deleted constructors in container classes.
 507   </para>
 508 </listitem>
 509
 510 <listitem>
 511   <para>
 512     <classname>unique_ptr</classname>.
 513   </para>
 514 </listitem>
 515
 516 <listitem>
 517   <para>
 518     Support for new character types <type>char16_t</type>
 519     and <type>char32_t</type> added
 520     to <classname>char_traits</classname>, <classname>basic_string</classname>, <classname>numeric_limits</classname>,
 521     and assorted compile-time type traits.
 522   </para>
 523 </listitem>
 524
 525 <listitem>
 526   <para>
 527     Support for string conversions <function>to_string</function>
 528     and <function>to_wstring</function>.
 529   </para>
 530 </listitem>
 531
 532 <listitem>
 533   <para>
 534     Member functions taking string arguments were added to iostreams
 535     including <classname>basic_filebuf</classname>, <classname>basic_ofstream</classname>,
 536     and <classname>basic_ifstream</classname>.
 537   </para>
 538 </listitem>
 539
 540 <listitem>
 541   <para>
 542     Exception propagation support,
 543     including <classname>exception_ptr</classname>, <function>current_exception</function>, <function>copy_exception</function>,
 544     and <function>rethrow_exception</function>.
 545   </para>
 546 </listitem>
 547 </itemizedlist>
 548
 549
 550   <para>
 551 Uglification of <literal>try</literal> to <literal>__try</literal>
 552 and <literal>catch</literal> to <literal>__catch</literal>.
 553   </para>
 554
 555   <para>
 556 Audit of internal mutex usage, conversion to functions returning static
 557 local mutex.
 558   </para>
 559
 560 <para> Extensions
 561 added: <filename class="headerfile">ext/pointer.h</filename>
 562 and <filename class="headerfile">ext/extptr_allocator.h</filename>. Support
 563 for non-standard pointer types has been added
 564 to <classname>vector</classname>
 565 and <classname>forward_list</classname>.
 566 </para>
 567 </section>
 568
 569 <section xml:id="api.rel_450"><info><title><constant>4.5</constant></title></info>
 570
 571   <para>
 572   </para>
 573
 574 <para>
 575 C++0X features.
 576 </para>
 577
 578 <itemizedlist>
 579 <listitem>
 580   <para>
 581     Added.
 582   </para>
 583   <para>
 584     <filename class="headerfile">functional</filename>,
 585     <filename class="headerfile">future</filename>,
 586     <filename class="headerfile">random</filename>
 587   </para>
 588 </listitem>
 589
 590 <listitem>
 591   <para>
 592     Updated and improved.
 593   </para>
 594   <para>
 595     <filename class="headerfile">atomic</filename>,
 596     <filename class="headerfile">system_error</filename>,
 597     <filename class="headerfile">type_traits</filename>
 598   </para>
 599 </listitem>
 600
 601 <listitem>
 602   <para>
 603     Add support for explicit operators and standard layout types.
 604   </para>
 605 </listitem>
 606 </itemizedlist>
 607
 608 <para>
 609 Profile mode first appears.
 610 </para>
 611
 612 <para>
 613 Support for decimal floating-point arithmetic, including <classname>decimal32</classname>, <classname>decimal64</classname>, and <classname>decimal128</classname>.
 614 </para>
 615
 616 <para>
 617 Python pretty-printers are added for use with appropriately-advanced versions of <command>gdb</command>.
 618 </para>
 619
 620 <para>
 621 Audit for application of function attributes nothrow, const, pure, and noreturn.
 622 </para>
 623
 624 <para>
 625 The default behavior for comparing typeinfo names changed, so
 626 in <filename class="headerfile">typeinfo</filename>, <literal>__GXX_MERGED_TYPEINFO_NAMES</literal>
 627 now defaults to zero.
 628 </para>
 629
 630 <para> Extensions modified: <filename class="headerfile">ext/throw_allocator.h</filename>.
 631 </para>
 632 </section>
 633
 634 <section xml:id="api.rel_460"><info><title><constant>4.6</constant></title></info>
 635
 636 <para>
 637   Use constexpr and nullptr where appropriate throughout the library.
 638 </para>
 639
 640 <para>
 641   The library was updated to avoid including
 642   <filename class="headerfile">stddef.h</filename> in order
 643   to reduce namespace pollution.
 644 </para>
 645
 646 <para>Reference-count annotations to assist data race detectors.
 647 </para>
 648
 649 <para>
 650   Added <function>make_exception_ptr</function> as an alias of
 651   <function>copy_exception</function>.
 652 </para>
 653
 654 </section>
 655
 656 <section xml:id="api.rel_470"><info><title><constant>4.7</constant></title></info>
 657
 658 <para>Use of noexcept throughout library.</para>
 659
 660 <para>Partial support for C++11 allocators first appears.</para>
 661
 662 <para>
 663   <classname>monotonic_clock</classname> renamed to
 664   <classname>steady_clock</classname> as required by the final C++11
 665   standard.
 666 </para>
 667
 668 <para>A new clocale model for newlib is available.</para>
 669
 670 <para>
 671   The library was updated to avoid including
 672   <filename class="headerfile">unistd.h</filename> in order
 673   to reduce namespace pollution.
 674 </para>
 675
 676 <para>Debug Mode was improved for unordered containers. </para>
 677
 678 </section>
 679
 680 <section xml:id="api.rel_480"><info><title><constant>4.8</constant></title></info>
 681
 682 <para>
 683   New random number engines and distributions.
 684   Optimisations for random.
 685 </para>
 686
 687 <para>New --enable-libstdcxx-verbose configure option</para>
 688
 689 <para>
 690   The --enable-libstdcxx-time configure option becomes unnecessary given a
 691   sufficiently recent glibc.
 692 </para>
 693
 694 </section>
 695
 696 <section xml:id="api.rel_490"><info><title><constant>4.9</constant></title></info>
 697
 698 <para> Implementation of <classname>regex</classname> completed. </para>
 699
 700 <para> C++14 library and TS implementations are added. </para>
 701
 702 <para> <function>copy_exception</function> deprecated. </para>
 703
 704 <para> <classname>__gnu_cxx::array_allocator</classname> deprecated. </para>
 705
 706 </section>
 707
 708 <section xml:id="api.rel_50"><info><title><constant>5</constant></title></info>
 709
 710 <para>
 711   ABI transition adds new implementations of several components, using the
 712   <code>abi_tag</code> attribute and the <code>__cxx11</code> inline
 713   namespace to distinguish the new entities from the old ones.
 714 </para>
 715
 716 <itemizedlist>
 717 <listitem>
 718   <para>
 719     Use of the new or old ABI can be selected per-translation unit with the
 720     <symbol>_GLIBCXX_USE_CXX11_ABI</symbol> macro.
 721   </para>
 722 </listitem>
 723 <listitem>
 724   <para>
 725     New non-reference-counted <classname>string</classname> implementation.
 726   </para>
 727 </listitem>
 728 <listitem>
 729   <para>
 730     New <classname>list</classname> implementation containing a new
 731     data member in order to provide O(1) <function>size()</function>.
 732   </para>
 733 </listitem>
 734 </itemizedlist>
 735
 736 <para>
 737   C++11 support completed (movable iostreams, new I/O manipulators,
 738   Unicode conversion utilities, atomic operations for
 739   <classname>shared_ptr</classname>, functions for notifying condition
 740   variables and making futures ready at thread exit).
 741 </para>
 742
 743 <para>
 744    Changed formatting of floating point types when
 745    <code>ios_base::fixed|ios_base::scientific</code> is set in a stream's
 746    format flags.
 747 </para>
 748
 749 <para> Improved C++14 support and TS implementations. </para>
 750
 751 <para> New random number engines and distributions. </para>
 752
 753 <para>
 754   GDB Xmethods for containers and <classname>unique_ptr</classname> added.
 755 </para>
 756
 757 <para>
 758   <classname>has_trivial_default_constructor</classname>,
 759   <classname>has_trivial_copy_constructor</classname> and
 760   <classname>has_trivial_copy_assign</classname> deprecated.
 761 </para>
 762
 763 </section>
 764 </section>