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 <para>
  17 A list of user-visible changes, in chronological order
  18 </para>
  19
  20 <section xml:id="api.rel_300"><info><title><constant>3.0</constant></title></info>
  21
  22
  23   <para>
  24 Extensions moved to <filename class="directory">include/ext</filename>.
  25   </para>
  26
  27 <para>
  28 Include files from the SGI/HP sources that pre-date the ISO standard
  29 are added. These files are placed into
  30 the <filename class="directory">include/backward</filename> directory and a deprecated warning
  31 is added that notifies on inclusion (<literal>-Wno-deprecated</literal>
  32 deactivates the warning.)
  33 </para>
  34
  35 <para>Deprecated include <filename class="headerfile">&lt;backward/strstream&gt;</filename> added.</para>
  36
  37 <para>Removal of include <filename class="headerfile">&lt;builtinbuf.h&gt;</filename>, <filename class="headerfile">&lt;indstream.h&gt;</filename>, <filename class="headerfile">&lt;parsestream.h&gt;</filename>, <filename class="headerfile">&lt;PlotFile.h&gt;</filename>, <filename class="headerfile">&lt;SFile.h&gt;</filename>, <filename class="headerfile">&lt;stdiostream.h&gt;</filename>, and <filename class="headerfile">&lt;stream.h&gt;</filename>.
  38 </para>
  39
  40
  41
  42 </section>
  43
  44 <section xml:id="api.rel_310"><info><title><constant>3.1</constant></title></info>
  45
  46   <para>
  47   </para>
  48
  49 <para>
  50 Extensions from SGI/HP moved from <code>namespace std</code>
  51 to <code>namespace __gnu_cxx</code>. As part of this, the following
  52 new includes are
  53 added: <filename class="headerfile">&lt;ext/algorithm&gt;</filename>, <filename class="headerfile">&lt;ext/functional&gt;</filename>, <filename class="headerfile">&lt;ext/iterator&gt;</filename>, <filename class="headerfile">&lt;ext/memory&gt;</filename>, and <filename class="headerfile">&lt;ext/numeric&gt;</filename>.
  54 </para>
  55
  56 <para>
  57 Extensions to <code>basic_filebuf</code> introduced: <code>__gnu_cxx::enc_filebuf</code>, and <code>__gnu_cxx::stdio_filebuf</code>.
  58 </para>
  59
  60 <para>
  61 Extensions to tree data structures added in <filename class="headerfile">&lt;ext/rb_tree&gt;</filename>.
  62 </para>
  63
  64 <para>
  65 Removal of <filename class="headerfile">&lt;ext/tree&gt;</filename>, moved to <filename class="headerfile">&lt;backward/tree.h&gt;</filename>.
  66 </para>
  67
  68 </section>
  69
  70 <section xml:id="api.rel_320"><info><title><constant>3.2</constant></title></info>
  71
  72   <para>
  73   </para>
  74 <para>Symbol versioning introduced for shared library.</para>
  75
  76 <para>Removal of include <filename class="headerfile">&lt;backward/strstream.h&gt;</filename>.</para>
  77
  78 <para>Allocator changes. Change <code>__malloc_alloc</code> to <code>malloc_allocator</code> and <code>__new_alloc</code> to <code>new_allocator</code>. </para>
  79
  80    <para> For GCC releases from 2.95 through the 3.1 series, defining
  81    <literal>__USE_MALLOC</literal> on the gcc command line would change the
  82    default allocation strategy to instead use <code>malloc</code> and
  83    <code>free</code>. For the 3.2 and 3.3 release series the same
  84    functionality was spelled <literal>_GLIBCXX_FORCE_NEW</literal>. From
  85    GCC 3.4 onwards the default allocator uses <code>new</code> anyway,
  86    but for the optional pooling allocators the functionality is enabled by
  87    setting <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">&lt;ext/pod_char_traits.h&gt;</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">&lt;ext/bitmap_allocator.h&gt;</filename>, <filename class="headerfile">&lt;ext/debug_allocator.h&gt;</filename>, <filename class="headerfile">&lt;ext/mt_allocator.h&gt;</filename>, <filename class="headerfile">&lt;ext/malloc_allocator.h&gt;</filename>,<filename class="headerfile">&lt;ext/new_allocator.h&gt;</filename>, <filename class="headerfile">&lt;ext/pool_allocator.h&gt;</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">&lt;ext/new_allocator.h&gt;</filename></entry>
 190     <entry><classname>std::__new_alloc</classname></entry>
 191     <entry><filename class="headerfile">&lt;memory&gt;</filename></entry>
 192   </row>
 193   <row>
 194     <entry><classname>__gnu_cxx::malloc_allocator&lt;T&gt;</classname></entry>
 195     <entry><filename class="headerfile">&lt;ext/malloc_allocator.h&gt;</filename></entry>
 196     <entry><classname>std::__malloc_alloc_template&lt;int&gt;</classname></entry>
 197     <entry><filename class="headerfile">&lt;memory&gt;</filename></entry>
 198   </row>
 199   <row>
 200     <entry><classname>__gnu_cxx::debug_allocator&lt;T&gt;</classname></entry>
 201     <entry><filename class="headerfile">&lt;ext/debug_allocator.h&gt;</filename></entry>
 202     <entry><classname>std::debug_alloc&lt;T&gt;</classname></entry>
 203     <entry><filename class="headerfile">&lt;memory&gt;</filename></entry>
 204   </row>
 205   <row>
 206     <entry><classname>__gnu_cxx::__pool_alloc&lt;T&gt;</classname></entry>
 207     <entry><filename class="headerfile">&lt;ext/pool_allocator.h&gt;</filename></entry>
 208     <entry><classname>std::__default_alloc_template&lt;bool,int&gt;</classname></entry>
 209     <entry><filename class="headerfile">&lt;memory&gt;</filename></entry>
 210   </row>
 211   <row>
 212     <entry><classname>__gnu_cxx::__mt_alloc&lt;T&gt;</classname></entry>
 213     <entry><filename class="headerfile">&lt;ext/mt_allocator.h&gt;</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">&lt;ext/bitmap_allocator.h&gt;</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">&lt;ext/array_allocator.h&gt;</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">&lt;ext/throw_allocator.h&gt;</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">&lt;ext/stdio_sync_filebuf.h&gt;</filename> added.
 279 </para>
 280
 281 <para>
 282 Extension <filename class="headerfile">&lt;ext/demangle.h&gt;</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">&lt;ext/array_allocator.h&gt;</filename> added.
 298 </para>
 299
 300 <para>
 301 Extension <code>codecvt</code> specializations moved to <filename class="headerfile">&lt;ext/codecvt_specializations.h&gt;</filename>.
 302 </para>
 303
 304 <para>
 305 Removal of <filename class="headerfile">&lt;ext/demangle.h&gt;</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">&lt;cassert&gt;</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">&lt;ext/typelist.h&gt;</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">&lt;ext/vstring.h&gt;</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">&lt;random&gt;</filename>, <filename class="headerfile">&lt;complex&gt;</filename>, and C compatibility headers added.</para>
 345
 346 <para> Extensions for concurrent programming consolidated
 347 into <filename class="headerfile">&lt;ext/concurrence.h&gt;</filename> and <filename class="headerfile">&lt;ext/atomicity.h&gt;</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">&lt;ext/type_traits.h&gt;</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">&lt;ext/typelist.h&gt;</filename>
 366 and <filename class="headerfile">&lt;ext/throw_allocator.h&gt;</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">&lt;regex&gt;</filename> and <filename class="headerfile">&lt;cmath&gt;</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">&lt;algobase.h&gt;</filename> <filename class="headerfile">&lt;algo.h&gt;</filename> <filename class="headerfile">&lt;alloc.h&gt;</filename> <filename class="headerfile">&lt;bvector.h&gt;</filename> <filename class="headerfile">&lt;complex.h&gt;</filename>
 392 <filename class="headerfile">&lt;defalloc.h&gt;</filename> <filename class="headerfile">&lt;deque.h&gt;</filename> <filename class="headerfile">&lt;fstream.h&gt;</filename> <filename class="headerfile">&lt;function.h&gt;</filename> <filename class="headerfile">&lt;hash_map.h&gt;</filename> <filename class="headerfile">&lt;hash_set.h&gt;</filename>
 393 <filename class="headerfile">&lt;hashtable.h&gt;</filename> <filename class="headerfile">&lt;heap.h&gt;</filename> <filename class="headerfile">&lt;iomanip.h&gt;</filename> <filename class="headerfile">&lt;iostream.h&gt;</filename> <filename class="headerfile">&lt;istream.h&gt;</filename> <filename class="headerfile">&lt;iterator.h&gt;</filename>
 394 <filename class="headerfile">&lt;list.h&gt;</filename> <filename class="headerfile">&lt;map.h&gt;</filename> <filename class="headerfile">&lt;multimap.h&gt;</filename> <filename class="headerfile">&lt;multiset.h&gt;</filename> <filename class="headerfile">&lt;new.h&gt;</filename> <filename class="headerfile">&lt;ostream.h&gt;</filename> <filename class="headerfile">&lt;pair.h&gt;</filename> <filename class="headerfile">&lt;queue.h&gt;</filename> <filename class="headerfile">&lt;rope.h&gt;</filename> <filename class="headerfile">&lt;set.h&gt;</filename> <filename class="headerfile">&lt;slist.h&gt;</filename> <filename class="headerfile">&lt;stack.h&gt;</filename> <filename class="headerfile">&lt;streambuf.h&gt;</filename> <filename class="headerfile">&lt;stream.h&gt;</filename> <filename class="headerfile">&lt;tempbuf.h&gt;</filename>
 395 <filename class="headerfile">&lt;tree.h&gt;</filename> <filename class="headerfile">&lt;vector.h&gt;</filename>
 396   </para>
 397   </listitem>
 398   <listitem>
 399     <para>Added</para>
 400   <para>
 401   <filename class="headerfile">&lt;hash_map&gt;</filename> and <filename class="headerfile">&lt;hash_set&gt;</filename>
 402   </para>
 403   </listitem>
 404   <listitem>
 405     <para>Added in C++11</para>
 406   <para>
 407     <filename class="headerfile">&lt;auto_ptr.h&gt;</filename> and <filename class="headerfile">&lt;binders.h&gt;</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">&lt;algorithm&gt;</filename> no longer includes <filename class="headerfile">&lt;climits&gt;</filename>, <filename class="headerfile">&lt;cstring&gt;</filename>, or <filename class="headerfile">&lt;iosfwd&gt;</filename> </para></listitem>
 419   <listitem><para><filename class="headerfile">&lt;bitset&gt;</filename> no longer includes <filename class="headerfile">&lt;istream&gt;</filename> or <filename class="headerfile">&lt;ostream&gt;</filename>, adds <filename class="headerfile">&lt;iosfwd&gt;</filename> </para></listitem>
 420   <listitem><para><filename class="headerfile">&lt;functional&gt;</filename> no longer includes <filename class="headerfile">&lt;cstddef&gt;</filename></para></listitem>
 421   <listitem><para><filename class="headerfile">&lt;iomanip&gt;</filename> no longer includes <filename class="headerfile">&lt;istream&gt;</filename>, <filename class="headerfile">&lt;istream&gt;</filename>, or <filename class="headerfile">&lt;functional&gt;</filename>, adds <filename class="headerfile">&lt;ioswd&gt;</filename> </para></listitem>
 422   <listitem><para><filename class="headerfile">&lt;numeric&gt;</filename> no longer includes <filename class="headerfile">&lt;iterator&gt;</filename></para></listitem>
 423   <listitem><para><filename class="headerfile">&lt;string&gt;</filename> no longer includes <filename class="headerfile">&lt;algorithm&gt;</filename> or <filename class="headerfile">&lt;memory&gt;</filename></para></listitem>
 424
 425   <listitem><para><filename class="headerfile">&lt;valarray&gt;</filename> no longer includes <filename class="headerfile">&lt;numeric&gt;</filename> or <filename class="headerfile">&lt;cstdlib&gt;</filename></para></listitem>
 426   <listitem><para><filename class="headerfile">&lt;tr1/hashtable&gt;</filename> no longer includes <filename class="headerfile">&lt;memory&gt;</filename> or <filename class="headerfile">&lt;functional&gt;</filename></para></listitem>
 427   <listitem><para><filename class="headerfile">&lt;tr1/memory&gt;</filename> no longer includes <filename class="headerfile">&lt;algorithm&gt;</filename></para></listitem>
 428   <listitem><para><filename class="headerfile">&lt;tr1/random&gt;</filename> no longer includes <filename class="headerfile">&lt;algorithm&gt;</filename> or <filename class="headerfile">&lt;fstream&gt;</filename></para></listitem>
 429 </itemizedlist>
 430
 431 <para>
 432 Debug mode for <filename class="headerfile">&lt;unordered_map&gt;</filename> and <filename class="headerfile">&lt;unordered_set&gt;</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">&lt;tuple&gt;</filename> and
 440     <filename class="headerfile">&lt;functional&gt;</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">&lt;atomic&gt;</filename>,
 476     <filename class="headerfile">&lt;chrono&gt;</filename>,
 477     <filename class="headerfile">&lt;condition_variable&gt;</filename>,
 478     <filename class="headerfile">&lt;forward_list&gt;</filename>,
 479     <filename class="headerfile">&lt;initializer_list&gt;</filename>,
 480     <filename class="headerfile">&lt;mutex&gt;</filename>,
 481     <filename class="headerfile">&lt;ratio&gt;</filename>,
 482     <filename class="headerfile">&lt;thread&gt;</filename>
 483   </para>
 484 </listitem>
 485
 486 <listitem>
 487   <para>
 488     Updated and improved.
 489   </para>
 490   <para>
 491     <filename class="headerfile">&lt;algorithm&gt;</filename>,
 492     <filename class="headerfile">&lt;system_error&gt;</filename>,
 493     <filename class="headerfile">&lt;type_traits&gt;</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">&lt;ext/pointer.h&gt;</filename>
 562 and <filename class="headerfile">&lt;ext/extptr_allocator.h&gt;</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">&lt;functional&gt;</filename>,
 585     <filename class="headerfile">&lt;future&gt;</filename>,
 586     <filename class="headerfile">&lt;random&gt;</filename>
 587   </para>
 588 </listitem>
 589
 590 <listitem>
 591   <para>
 592     Updated and improved.
 593   </para>
 594   <para>
 595     <filename class="headerfile">&lt;atomic&gt;</filename>,
 596     <filename class="headerfile">&lt;system_error&gt;</filename>,
 597     <filename class="headerfile">&lt;type_traits&gt;</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">&lt;typeinfo&gt;</filename>, <literal>__GXX_MERGED_TYPEINFO_NAMES</literal>
 627 now defaults to zero.
 628 </para>
 629
 630 <para> Extensions modified: <filename class="headerfile">&lt;ext/throw_allocator.h&gt;</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">&lt;stddef.h&gt;</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">&lt;unistd.h&gt;</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_51"><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     <xref linkend="manual.intro.using.macros"><symbol>_GLIBCXX_USE_CXX11_ABI</symbol>
 721     macro</xref>.
 722   </para>
 723 </listitem>
 724 <listitem>
 725   <para>
 726     New non-reference-counted <classname>string</classname> implementation.
 727   </para>
 728 </listitem>
 729 <listitem>
 730   <para>
 731     New <classname>list</classname> implementation containing a new
 732     data member in order to provide O(1) <function>size()</function>.
 733   </para>
 734 </listitem>
 735 <listitem>
 736   <para>
 737     New <classname>ios_base::failure</classname> implementation inheriting
 738     from <classname>system_error</classname>.
 739   </para>
 740 </listitem>
 741 </itemizedlist>
 742
 743 <para>
 744   C++11 support completed (movable iostreams, new I/O manipulators,
 745   Unicode conversion utilities, atomic operations for
 746   <classname>shared_ptr</classname>, functions for notifying condition
 747   variables and making futures ready at thread exit).
 748 </para>
 749
 750 <para>
 751    Changed formatting of floating point types when
 752    <code>ios_base::fixed|ios_base::scientific</code> is set in a stream's
 753    format flags.
 754 </para>
 755
 756 <para> Improved C++14 support and TS implementations. </para>
 757
 758 <para> New random number engines and distributions. </para>
 759
 760 <para>
 761   GDB Xmethods for containers and <classname>unique_ptr</classname> added.
 762 </para>
 763
 764 <para>
 765   <classname>has_trivial_default_constructor</classname>,
 766   <classname>has_trivial_copy_constructor</classname> and
 767   <classname>has_trivial_copy_assign</classname> deprecated.
 768 </para>
 769
 770 <section xml:id="api.rel_53"><info><title><constant>5.3</constant></title></info>
 771 <para> Experimental implementation of the C++ Filesystem TS added. </para>
 772
 773 </section>
 774
 775 </section>
 776
 777 <section xml:id="api.rel_61"><info><title><constant>6</constant></title></info>
 778
 779 <para> C++14 support completed. </para>
 780
 781 <para>
 782   Support for mathematical special functions (ISO/IEC 29124:2010) added.
 783 </para>
 784
 785 <para>
 786   Assertions to check function preconditions can be enabled by defining the
 787   <link linkend="manual.intro.using.macros"><symbol>_GLIBCXX_ASSERTIONS</symbol>
 788   macro</link>.
 789   The initial set of assertions are a subset of the checks enabled by
 790   the Debug Mode, but without the ABI changes and changes to algorithmic
 791   complexity that are caused by enabling the full Debug Mode.
 792 </para>
 793
 794 </section>
 795
 796 <section xml:id="api.rel_71"><info><title><constant>7</constant></title></info>
 797
 798 <para>
 799   The type of exception thrown by iostreams changed to the <code>cxx11</code>
 800   ABI version of <classname>std::ios_base::failure</classname>.
 801 </para>
 802
 803 <para>
 804   Experimental C++17 support added, including most new library features.
 805   The meaning of <classname>shared_ptr&lt;T[]&gt;</classname> changed to
 806   match the C++17 semantics.
 807 </para>
 808
 809 <para>
 810   <xref linkend="manual.intro.using.macros"><symbol>_GLIBCXX_RELEASE</symbol>
 811   macro</xref> added.
 812 </para>
 813
 814 <para>
 815   <classname>has_trivial_default_constructor</classname>,
 816   <classname>has_trivial_copy_constructor</classname> and
 817   <classname>has_trivial_copy_assign</classname> removed.
 818 </para>
 819
 820 <para> Profile Mode was deprecated. </para>
 821
 822 <section xml:id="api.rel_72"><info><title><constant>7.2</constant></title></info>
 823
 824 <para>
 825   Library Fundamentals TS header
 826   <filename class="headerfile">&lt;experimental/source_location&gt;</filename>
 827   added.
 828 </para>
 829
 830 </section>
 831
 832 <section xml:id="api.rel_73"><info><title><constant>7.3</constant></title></info>
 833
 834 <para>
 835   Including new C++14 or C++17 headers without a suitable <option>-std</option>
 836   no longer causes compilation to fail via <literal>#error</literal>.
 837   Instead the header is simply empty and doesn't define anything.
 838 </para>
 839
 840 </section>
 841
 842 </section>
 843
 844 <section xml:id="api.rel_81"><info><title><constant>8</constant></title></info>
 845
 846 <para>
 847   The exceptions thrown by iostreams can now be caught by handlers for either
 848   version of <classname>std::ios_base::failure</classname>.
 849 </para>
 850
 851 <para>
 852   Improved experimental C++17 support. Headers
 853   <filename class="headerfile">&lt;charconv&gt;</filename> and
 854   <filename class="headerfile">&lt;filesystem&gt;</filename>.
 855   Experimental implementation of the C++17 Filesystem library added.
 856 </para>
 857
 858 <para>
 859   Experimental C++2a support
 860   (<function>to_address</function> and <classname>endian</classname>).
 861 </para>
 862
 863 <para>
 864   AddressSanitizer annotations added to <classname>std::vector</classname>
 865   to detect out-of-range accesses to the unused capacity of a vector.
 866 </para>
 867
 868 <para>
 869   <function>std::char_traits&lt;char16_t&gt;::to_int_type(u'\uFFFF')</function>
 870   now returns <literal>0xFFFD</literal>, as <literal>0xFFFF</literal> is
 871   used for <function>std::char_traits&lt;char16_t&gt;::eof()</function>.
 872 </para>
 873
 874 <para>
 875   The extension allowing arithmetic on
 876   <classname>std::atomic&lt;void*&gt;</classname> and types like
 877   <classname>std::atomic&lt;R(*)()&gt;</classname> was deprecated.
 878 </para>
 879
 880 <para>
 881   The <function>std::uncaught_exception</function> function was deprecated
 882   for C++17 mode.
 883 </para>
 884
 885 <para>
 886   The nested typedefs <type>std::hash::result_type</type> and
 887   <type>std::hash::argument_type</type> were deprecated for C++17 mode.
 888 </para>
 889
 890 <para>
 891   The deprecated iostream members <type>ios_base::io_state</type>,
 892   <type>ios_base::open_mode</type>, <type>ios_base::seek_dir</type>, and
 893   <function>basic_streambuf::stossc</function> were removed for C++17 mode.
 894 </para>
 895
 896 <para>
 897   The non-standard C++0x <function>std::copy_exception</function> function
 898   was removed.
 899 </para>
 900
 901 <para>
 902   For <option>-std=c++11</option>, <option>-std=c++14</option>, and
 903   <option>-std=c++17</option> modes the <filename>&lt;complex.h&gt;</filename>
 904   header no longer includes the C99 <filename>&lt;complex.h&gt;</filename>
 905   header.
 906 </para>
 907
 908 <para>
 909   For the non-default <option>--enable-symvers=gnu-versioned-namespace</option>
 910   configuration, the shared library SONAME has been changed to
 911   <filename>libstdc++.so.8</filename>.
 912 </para>
 913
 914 </section>
 915
 916 <section xml:id="api.rel_91"><info><title><constant>9</constant></title></info>
 917
 918 <para>
 919   C++17 header
 920   <filename class="headerfile">&lt;memory_resource&gt;</filename>
 921   added.
 922 </para>
 923
 924 <para>
 925   Experimental C++2a support improved, with new headers
 926   <filename class="headerfile">&lt;bit&gt;</filename> and
 927   <filename class="headerfile">&lt;version&gt;</filename> added.
 928   Support for new character type <type>char8_t</type> added
 929   to <classname>char_traits</classname>, <classname>basic_string</classname>,
 930   <classname>numeric_limits</classname>,
 931   and relevant locale facets and type traits.
 932 </para>
 933
 934 <para>
 935   Experimental implementation of the Networking TS library added,
 936   with new headers
 937   <filename class="headerfile">&lt;experimental/buffer&gt;</filename>,
 938   <filename class="headerfile">&lt;experimental/executor&gt;</filename>,
 939   <filename class="headerfile">&lt;experimental/internet&gt;</filename>,
 940   <filename class="headerfile">&lt;experimental/io_context&gt;</filename>,
 941   <filename class="headerfile">&lt;experimental/net&gt;</filename>,
 942   <filename class="headerfile">&lt;experimental/netfwd&gt;</filename>,
 943   <filename class="headerfile">&lt;experimental/socket&gt;</filename>,
 944   and
 945   <filename class="headerfile">&lt;experimental/timer&gt;</filename>.
 946 </para>
 947
 948 </section>
 949
 950 <section xml:id="api.rel_101"><info><title><constant>10</constant></title></info>
 951 <para> Deprecated features removed:
 952 <itemizedlist>
 953 <listitem> Profile Mode </listitem>
 954 <listitem> <classname>__gnu_cxx::array_allocator</classname> </listitem>
 955 </itemizedlist>
 956 </para>
 957
 958 <para>
 959   The non-standard <function>std::__is_nullptr_t</function> type trait
 960   was deprecated.
 961 </para>
 962
 963 <para>
 964   The <classname>std::packaged_task</classname> constructors taking
 965   an allocator argument are only defined for C++11 and C++14.
 966 </para>
 967
 968 <para>
 969   Several members of <classname>std::allocator</classname> were removed
 970   for C++20 mode. The removed functionality has been provided by
 971   <classname>std::allocator_traits</classname> since C++11 and that should
 972   be used instead.
 973 </para>
 974
 975 <para>
 976   The type of the <classname>std::iterator</classname> base class of
 977   <classname>std::istreambuf_iterator</classname> was changed to be
 978   consistent for all <option>-std</option> modes.
 979   Before GCC 10.1 the base class had one type in C++98 mode and a
 980   different type in C++11 and later modes. The type in C++98 mode
 981   was changed to be the same as for C++11 and later.
 982 </para>
 983
 984 <para>
 985   Experimental C++2a support improved, with new headers
 986   <filename class="headerfile">&lt;concepts&gt;</filename>,
 987   <filename class="headerfile">&lt;ranges&gt;</filename>,
 988   <filename class="headerfile">&lt;compare&gt;</filename>,
 989   <filename class="headerfile">&lt;coroutine&gt;</filename>,
 990   <filename class="headerfile">&lt;numbers&gt;</filename>,
 991   <filename class="headerfile">&lt;span&gt;</filename>,
 992   and
 993   <filename class="headerfile">&lt;stop_token&gt;</filename>
 994   added.
 995 </para>
 996
 997 </section>
 998
 999 <section xml:id="api.rel_111"><info><title><constant>11</constant></title></info>
1000
1001 <para>
1002   The <option>--enable-cheaders=c_std</option> configuration
1003   was deprecated.
1004 </para>
1005
1006 <para>
1007   When compiling as C++20, the <function>operator&gt;&gt;</function> overloads
1008   for extracting strings into character buffers only work with arrays,
1009   not raw pointers.
1010 </para>
1011
1012 <para>
1013   <code>std::string::reserve(n)</code> will no longer reduce
1014   the string's capacity.
1015   Calling <function>reserve()</function> with no arguments is equivalent
1016   to <function>shrink_to_fit()</function>, but is deprecated.
1017   <function>shrink_to_fit()</function> should be used instead.
1018 </para>
1019
1020 </section>
1021
1022 <section xml:id="api.rel_121"><info><title><constant>12</constant></title></info>
1023
1024 <para>
1025 The <function>std::random_shuffle</function> algorithms are deprecated
1026 for C++14 and later. The C++11 <function>std::shuffle</function> algorithm
1027 can be used instead.
1028 </para>
1029
1030 <para>
1031 The <function>std::unexpected</function> function and related typedef and
1032 accessors for the unexpected handler are deprecated for C++11 and later.
1033 Dynamic exception specifications should be replaced with <code>noexcept</code>.
1034 </para>
1035
1036 <para>
1037 The <literal>bitmap</literal>, <literal>mt</literal>, and <literal>pool</literal>
1038 options for <option>--enable-libstdcxx-allocator</option> were removed.
1039 For the <literal>new</literal> option, <classname>std::allocator</classname>
1040 no longer derives from <classname>__gnu_cxx::new_allocator</classname>;
1041 they both derive from <classname>std::__new_allocator</classname> instead.
1042 </para>
1043
1044 </section>
1045
1046 </section>