1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>API Evolution and Deprecation History</title><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><meta name="keywords" content="ISO C++, api, evolution, deprecation, history" /><meta name="keywords" content="ISO C++, library" /><meta name="keywords" content="ISO C++, runtime, library" /><link rel="home" href="../index.html" title="The GNU C++ Library" /><link rel="up" href="appendix_porting.html" title="Appendix B. Porting and Maintenance" /><link rel="prev" href="abi.html" title="ABI Policy and Guidelines" /><link rel="next" href="backwards.html" title="Backwards Compatibility" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">API Evolution and Deprecation History</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="abi.html">Prev</a> </td><th width="60%" align="center">Appendix B. 3 Porting and Maintenance 4 5</th><td width="20%" align="right"> <a accesskey="n" href="backwards.html">Next</a></td></tr></table><hr /></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="appendix.porting.api"></a>API Evolution and Deprecation History</h2></div></div></div><p> 6A list of user-visible changes, in chronological order 7</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_300"></a><code class="constant">3.0</code></h3></div></div></div><p> 8Extensions moved to <code class="filename">include/ext</code>. 9 </p><p> 10Include files from the SGI/HP sources that pre-date the ISO standard 11are added. These files are placed into 12the <code class="filename">include/backward</code> directory and a deprecated warning 13is added that notifies on inclusion (<code class="literal">-Wno-deprecated</code> 14deactivates the warning.) 15</p><p>Deprecated include <code class="filename"><backward/strstream></code> added.</p><p>Removal of include <code class="filename"><builtinbuf.h></code>, <code class="filename"><indstream.h></code>, <code class="filename"><parsestream.h></code>, <code class="filename"><PlotFile.h></code>, <code class="filename"><SFile.h></code>, <code class="filename"><stdiostream.h></code>, and <code class="filename"><stream.h></code>. 16</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_310"></a><code class="constant">3.1</code></h3></div></div></div><p> 17 </p><p> 18Extensions from SGI/HP moved from <code class="code">namespace std</code> 19to <code class="code">namespace __gnu_cxx</code>. As part of this, the following 20new includes are 21added: <code class="filename"><ext/algorithm></code>, <code class="filename"><ext/functional></code>, <code class="filename"><ext/iterator></code>, <code class="filename"><ext/memory></code>, and <code class="filename"><ext/numeric></code>. 22</p><p> 23Extensions to <code class="code">basic_filebuf</code> introduced: <code class="code">__gnu_cxx::enc_filebuf</code>, and <code class="code">__gnu_cxx::stdio_filebuf</code>. 24</p><p> 25Extensions to tree data structures added in <code class="filename"><ext/rb_tree></code>. 26</p><p> 27Removal of <code class="filename"><ext/tree></code>, moved to <code class="filename"><backward/tree.h></code>. 28</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_320"></a><code class="constant">3.2</code></h3></div></div></div><p> 29 </p><p>Symbol versioning introduced for shared library.</p><p>Removal of include <code class="filename"><backward/strstream.h></code>.</p><p>Allocator changes. Change <code class="code">__malloc_alloc</code> to <code class="code">malloc_allocator</code> and <code class="code">__new_alloc</code> to <code class="code">new_allocator</code>. </p><p> For GCC releases from 2.95 through the 3.1 series, defining 30 <code class="literal">__USE_MALLOC</code> on the gcc command line would change the 31 default allocation strategy to instead use <code class="code">malloc</code> and 32 <code class="code">free</code>. For the 3.2 and 3.3 release series the same 33 functionality was spelled <code class="literal">_GLIBCXX_FORCE_NEW</code>. From 34 GCC 3.4 onwards the default allocator uses <code class="code">new</code> anyway, 35 but for the optional pooling allocators the functionality is enabled by 36 setting <code class="literal">GLIBCXX_FORCE_NEW</code> in the environment, see 37 <a class="link" href="mt_allocator.html" title="Chapter 19. The mt_allocator">the mt allocator chapter</a> 38 for details. 39 </p><p>Error handling in iostreams cleaned up, made consistent. </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_330"></a><code class="constant">3.3</code></h3></div></div></div><p> 40 </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_340"></a><code class="constant">3.4</code></h3></div></div></div><p> 41 </p><p> 42Large file support. 43</p><p> Extensions for generic characters and <code class="code">char_traits</code> added in <code class="filename"><ext/pod_char_traits.h></code>. 44</p><p> 45Support for <code class="code">wchar_t</code> specializations of <code class="code">basic_filebuf</code> enhanced to support <code class="code">UTF-8</code> and <code class="code">Unicode</code>, depending on host. More hosts support basic <code class="code">wchar_t</code> functionality. 46</p><p> 47Support for <code class="code">char_traits</code> beyond builtin types. 48</p><p> 49Conformant <code class="code">allocator</code> class and usage in containers. As 50part of this, the following extensions are 51added: <code class="filename"><ext/bitmap_allocator.h></code>, <code class="filename"><ext/debug_allocator.h></code>, <code class="filename"><ext/mt_allocator.h></code>, <code class="filename"><ext/malloc_allocator.h></code>,<code class="filename"><ext/new_allocator.h></code>, <code class="filename"><ext/pool_allocator.h></code>. 52</p><p> 53This is a change from all previous versions, and may require 54source-level changes due to allocator-related changes to structures 55names and template parameters, filenames, and file locations. Some, 56like <code class="code">__simple_alloc, __allocator, __alloc, </code> and <code class="code"> 57_Alloc_traits</code> have been removed. 58</p><p>Default behavior of <code class="code">std::allocator</code> has changed.</p><p> 59 Previous versions prior to 3.4 cache allocations in a memory 60 pool, instead of passing through to call the global allocation 61 operators (i.e., <code class="classname">__gnu_cxx::pool_allocator</code>). More 62 recent versions default to the 63 simpler <code class="classname">__gnu_cxx::new_allocator</code>. 64</p><p> Previously, all allocators were written to the SGI 65 style, and all STL containers expected this interface. This 66 interface had a traits class called <code class="code">_Alloc_traits</code> that 67 attempted to provide more information for compile-time allocation 68 selection and optimization. This traits class had another allocator 69 wrapper, <code class="code">__simple_alloc<T,A></code>, which was a 70 wrapper around another allocator, A, which itself is an allocator 71 for instances of T. But wait, there's more: 72 <code class="code">__allocator<T,A></code> is another adapter. Many of 73 the provided allocator classes were SGI style: such classes can be 74 changed to a conforming interface with this wrapper: 75 <code class="code">__allocator<T, __alloc></code> is thus the same as 76 <code class="code">allocator<T></code>. 77 </p><p> The class <code class="classname">allocator</code> used the typedef 78 <span class="type">__alloc</span> to select an underlying allocator that 79 satisfied memory allocation requests. The selection of this 80 underlying allocator was not user-configurable. 81 </p><div class="table"><a id="table.extension_allocators"></a><p class="title"><strong>Table B.6. Extension Allocators</strong></p><div class="table-contents"><table class="table" summary="Extension Allocators" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Allocator (3.4)</th><th align="left">Header (3.4)</th><th align="left">Allocator (3.[0-3])</th><th align="left">Header (3.[0-3])</th></tr></thead><tbody><tr><td align="left"><code class="classname">__gnu_cxx::new_allocator<T></code></td><td align="left"><code class="filename"><ext/new_allocator.h></code></td><td align="left"><code class="classname">std::__new_alloc</code></td><td align="left"><code class="filename"><memory></code></td></tr><tr><td align="left"><code class="classname">__gnu_cxx::malloc_allocator<T></code></td><td align="left"><code class="filename"><ext/malloc_allocator.h></code></td><td align="left"><code class="classname">std::__malloc_alloc_template<int></code></td><td align="left"><code class="filename"><memory></code></td></tr><tr><td align="left"><code class="classname">__gnu_cxx::debug_allocator<T></code></td><td align="left"><code class="filename"><ext/debug_allocator.h></code></td><td align="left"><code class="classname">std::debug_alloc<T></code></td><td align="left"><code class="filename"><memory></code></td></tr><tr><td align="left"><code class="classname">__gnu_cxx::__pool_alloc<T></code></td><td align="left"><code class="filename"><ext/pool_allocator.h></code></td><td align="left"><code class="classname">std::__default_alloc_template<bool,int></code></td><td align="left"><code class="filename"><memory></code></td></tr><tr><td align="left"><code class="classname">__gnu_cxx::__mt_alloc<T></code></td><td align="left"><code class="filename"><ext/mt_allocator.h></code></td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left"><code class="classname">__gnu_cxx::bitmap_allocator<T></code></td><td align="left"><code class="filename"><ext/bitmap_allocator.h></code></td><td align="left"> </td><td align="left"> </td></tr></tbody></table></div></div><br class="table-break" /><p> Releases after gcc-3.4 have continued to add to the collection 82 of available allocators. All of these new allocators are 83 standard-style. The following table includes details, along with 84 the first released version of GCC that included the extension allocator. 85 </p><div class="table"><a id="table.extension_allocators2"></a><p class="title"><strong>Table B.7. Extension Allocators Continued</strong></p><div class="table-contents"><table class="table" summary="Extension Allocators Continued" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /></colgroup><thead><tr><th align="left">Allocator</th><th align="left">Include</th><th align="left">Version</th></tr></thead><tbody><tr><td align="left"><code class="classname">__gnu_cxx::array_allocator<T></code></td><td align="left"><code class="filename"><ext/array_allocator.h></code></td><td align="left">4.0.0</td></tr><tr><td align="left"><code class="classname">__gnu_cxx::throw_allocator<T></code></td><td align="left"><code class="filename"><ext/throw_allocator.h></code></td><td align="left">4.2.0</td></tr></tbody></table></div></div><br class="table-break" /><p> 86Debug mode first appears. 87</p><p> 88Precompiled header support <acronym class="acronym">PCH</acronym> support. 89</p><p> 90Macro guard for changed, from <code class="literal">_GLIBCPP_</code> to <code class="literal">_GLIBCXX_</code>. 91</p><p> 92Extension <code class="filename"><ext/stdio_sync_filebuf.h></code> added. 93</p><p> 94Extension <code class="filename"><ext/demangle.h></code> added. 95</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_400"></a><code class="constant">4.0</code></h3></div></div></div><p> 96 </p><p> 97TR1 features first appear. 98</p><p> 99Extension allocator <code class="filename"><ext/array_allocator.h></code> added. 100</p><p> 101Extension <code class="code">codecvt</code> specializations moved to <code class="filename"><ext/codecvt_specializations.h></code>. 102</p><p> 103Removal of <code class="filename"><ext/demangle.h></code>. 104</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_410"></a><code class="constant">4.1</code></h3></div></div></div><p> 105 </p><p> 106Removal of <code class="filename"><cassert></code> from all standard headers: now has to be explicitly included for <code class="code">std::assert</code> calls. 107</p><p> Extensions for policy-based data structures first added. New includes, 108types, namespace <code class="code">pb_assoc</code>. 109</p><p> Extensions for typelists added in <code class="filename"><ext/typelist.h></code>. 110</p><p> Extension for policy-based <code class="code">basic_string</code> first added: <code class="code">__gnu_cxx::__versa_string</code> in <code class="filename"><ext/vstring.h></code>. 111</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_420"></a><code class="constant">4.2</code></h3></div></div></div><p> 112 </p><p> Default visibility attributes applied to <code class="code">namespace std</code>. Support for <code class="code">-fvisibility</code>. 113</p><p>TR1 <code class="filename"><random></code>, <code class="filename"><complex></code>, and C compatibility headers added.</p><p> Extensions for concurrent programming consolidated 114into <code class="filename"><ext/concurrence.h></code> and <code class="filename"><ext/atomicity.h></code>, 115including change of namespace to <code class="code">__gnu_cxx</code> in some 116cases. Added types 117include <code class="code">_Lock_policy</code>, <code class="code">__concurrence_lock_error</code>, <code class="code">__concurrence_unlock_error</code>, <code class="code">__mutex</code>, <code class="code">__scoped_lock</code>.</p><p> Extensions for type traits consolidated 118into <code class="filename"><ext/type_traits.h></code>. Additional traits are added 119(<code class="code">__conditional_type</code>, <code class="code">__enable_if</code>, others.) 120</p><p> Extensions for policy-based data structures revised. New includes, 121types, namespace moved to <code class="code">__pb_ds</code>. 122</p><p> Extensions for debug mode modified: now nested in <code class="code">namespace 123std::__debug</code> and extensions in <code class="code">namespace 124__gnu_cxx::__debug</code>.</p><p> Extensions added: <code class="filename"><ext/typelist.h></code> 125and <code class="filename"><ext/throw_allocator.h></code>. 126</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_430"></a><code class="constant">4.3</code></h3></div></div></div><p> 127 </p><p> 128C++0X features first appear. 129</p><p>TR1 <code class="filename"><regex></code> and <code class="filename"><cmath></code>'s mathematical special function added. 130</p><p> 131Backward include edit. 132</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Removed</p><p> 133<code class="filename"><algobase.h></code> <code class="filename"><algo.h></code> <code class="filename"><alloc.h></code> <code class="filename"><bvector.h></code> <code class="filename"><complex.h></code> 134<code class="filename"><defalloc.h></code> <code class="filename"><deque.h></code> <code class="filename"><fstream.h></code> <code class="filename"><function.h></code> <code class="filename"><hash_map.h></code> <code class="filename"><hash_set.h></code> 135<code class="filename"><hashtable.h></code> <code class="filename"><heap.h></code> <code class="filename"><iomanip.h></code> <code class="filename"><iostream.h></code> <code class="filename"><istream.h></code> <code class="filename"><iterator.h></code> 136<code class="filename"><list.h></code> <code class="filename"><map.h></code> <code class="filename"><multimap.h></code> <code class="filename"><multiset.h></code> <code class="filename"><new.h></code> <code class="filename"><ostream.h></code> <code class="filename"><pair.h></code> <code class="filename"><queue.h></code> <code class="filename"><rope.h></code> <code class="filename"><set.h></code> <code class="filename"><slist.h></code> <code class="filename"><stack.h></code> <code class="filename"><streambuf.h></code> <code class="filename"><stream.h></code> <code class="filename"><tempbuf.h></code> 137<code class="filename"><tree.h></code> <code class="filename"><vector.h></code> 138 </p></li><li class="listitem"><p>Added</p><p> 139 <code class="filename"><hash_map></code> and <code class="filename"><hash_set></code> 140 </p></li><li class="listitem"><p>Added in C++11</p><p> 141 <code class="filename"><auto_ptr.h></code> and <code class="filename"><binders.h></code> 142 </p></li></ul></div><p> 143Header dependency streamlining. 144</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><code class="filename"><algorithm></code> no longer includes <code class="filename"><climits></code>, <code class="filename"><cstring></code>, or <code class="filename"><iosfwd></code> </p></li><li class="listitem"><p><code class="filename"><bitset></code> no longer includes <code class="filename"><istream></code> or <code class="filename"><ostream></code>, adds <code class="filename"><iosfwd></code> </p></li><li class="listitem"><p><code class="filename"><functional></code> no longer includes <code class="filename"><cstddef></code></p></li><li class="listitem"><p><code class="filename"><iomanip></code> no longer includes <code class="filename"><istream></code>, <code class="filename"><istream></code>, or <code class="filename"><functional></code>, adds <code class="filename"><ioswd></code> </p></li><li class="listitem"><p><code class="filename"><numeric></code> no longer includes <code class="filename"><iterator></code></p></li><li class="listitem"><p><code class="filename"><string></code> no longer includes <code class="filename"><algorithm></code> or <code class="filename"><memory></code></p></li><li class="listitem"><p><code class="filename"><valarray></code> no longer includes <code class="filename"><numeric></code> or <code class="filename"><cstdlib></code></p></li><li class="listitem"><p><code class="filename"><tr1/hashtable></code> no longer includes <code class="filename"><memory></code> or <code class="filename"><functional></code></p></li><li class="listitem"><p><code class="filename"><tr1/memory></code> no longer includes <code class="filename"><algorithm></code></p></li><li class="listitem"><p><code class="filename"><tr1/random></code> no longer includes <code class="filename"><algorithm></code> or <code class="filename"><fstream></code></p></li></ul></div><p> 145Debug mode for <code class="filename"><unordered_map></code> and <code class="filename"><unordered_set></code>. 146</p><p> 147Parallel mode first appears. 148</p><p>Variadic template implementations of items in <code class="filename"><tuple></code> and 149 <code class="filename"><functional></code>. 150</p><p>Default <code class="code">what</code> implementations give more elaborate 151 exception strings for <code class="code">bad_cast</code>, 152 <code class="code">bad_typeid</code>, <code class="code">bad_exception</code>, and 153 <code class="code">bad_alloc</code>. 154</p><p> 155PCH binary files no longer installed. Instead, the source files are installed. 156</p><p> 157Namespace pb_ds moved to __gnu_pb_ds. 158</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_440"></a><code class="constant">4.4</code></h3></div></div></div><p> 159 </p><p> 160C++0X features. 161</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> 162 Added. 163 </p><p> 164 <code class="filename"><atomic></code>, 165 <code class="filename"><chrono></code>, 166 <code class="filename"><condition_variable></code>, 167 <code class="filename"><forward_list></code>, 168 <code class="filename"><initializer_list></code>, 169 <code class="filename"><mutex></code>, 170 <code class="filename"><ratio></code>, 171 <code class="filename"><thread></code> 172 </p></li><li class="listitem"><p> 173 Updated and improved. 174 </p><p> 175 <code class="filename"><algorithm></code>, 176 <code class="filename"><system_error></code>, 177 <code class="filename"><type_traits></code> 178 </p></li><li class="listitem"><p> 179 Use of the GNU extension namespace association converted to inline namespaces. 180 </p></li><li class="listitem"><p> 181 Preliminary support for <code class="classname">initializer_list</code> 182 and defaulted and deleted constructors in container classes. 183 </p></li><li class="listitem"><p> 184 <code class="classname">unique_ptr</code>. 185 </p></li><li class="listitem"><p> 186 Support for new character types <span class="type">char16_t</span> 187 and <span class="type">char32_t</span> added 188 to <code class="classname">char_traits</code>, <code class="classname">basic_string</code>, <code class="classname">numeric_limits</code>, 189 and assorted compile-time type traits. 190 </p></li><li class="listitem"><p> 191 Support for string conversions <code class="function">to_string</code> 192 and <code class="function">to_wstring</code>. 193 </p></li><li class="listitem"><p> 194 Member functions taking string arguments were added to iostreams 195 including <code class="classname">basic_filebuf</code>, <code class="classname">basic_ofstream</code>, 196 and <code class="classname">basic_ifstream</code>. 197 </p></li><li class="listitem"><p> 198 Exception propagation support, 199 including <code class="classname">exception_ptr</code>, <code class="function">current_exception</code>, <code class="function">copy_exception</code>, 200 and <code class="function">rethrow_exception</code>. 201 </p></li></ul></div><p> 202Uglification of <code class="literal">try</code> to <code class="literal">__try</code> 203and <code class="literal">catch</code> to <code class="literal">__catch</code>. 204 </p><p> 205Audit of internal mutex usage, conversion to functions returning static 206local mutex. 207 </p><p> Extensions 208added: <code class="filename"><ext/pointer.h></code> 209and <code class="filename"><ext/extptr_allocator.h></code>. Support 210for non-standard pointer types has been added 211to <code class="classname">vector</code> 212and <code class="classname">forward_list</code>. 213</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_450"></a><code class="constant">4.5</code></h3></div></div></div><p> 214 </p><p> 215C++0X features. 216</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> 217 Added. 218 </p><p> 219 <code class="filename"><functional></code>, 220 <code class="filename"><future></code>, 221 <code class="filename"><random></code> 222 </p></li><li class="listitem"><p> 223 Updated and improved. 224 </p><p> 225 <code class="filename"><atomic></code>, 226 <code class="filename"><system_error></code>, 227 <code class="filename"><type_traits></code> 228 </p></li><li class="listitem"><p> 229 Add support for explicit operators and standard layout types. 230 </p></li></ul></div><p> 231Profile mode first appears. 232</p><p> 233Support for decimal floating-point arithmetic, including <code class="classname">decimal32</code>, <code class="classname">decimal64</code>, and <code class="classname">decimal128</code>. 234</p><p> 235Python pretty-printers are added for use with appropriately-advanced versions of <span class="command"><strong>gdb</strong></span>. 236</p><p> 237Audit for application of function attributes nothrow, const, pure, and noreturn. 238</p><p> 239The default behavior for comparing typeinfo names changed, so 240in <code class="filename"><typeinfo></code>, <code class="literal">__GXX_MERGED_TYPEINFO_NAMES</code> 241now defaults to zero. 242</p><p> Extensions modified: <code class="filename"><ext/throw_allocator.h></code>. 243</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_460"></a><code class="constant">4.6</code></h3></div></div></div><p> 244 Use constexpr and nullptr where appropriate throughout the library. 245</p><p> 246 The library was updated to avoid including 247 <code class="filename"><stddef.h></code> in order 248 to reduce namespace pollution. 249</p><p>Reference-count annotations to assist data race detectors. 250</p><p> 251 Added <code class="function">make_exception_ptr</code> as an alias of 252 <code class="function">copy_exception</code>. 253</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_470"></a><code class="constant">4.7</code></h3></div></div></div><p>Use of noexcept throughout library.</p><p>Partial support for C++11 allocators first appears.</p><p> 254 <code class="classname">monotonic_clock</code> renamed to 255 <code class="classname">steady_clock</code> as required by the final C++11 256 standard. 257</p><p>A new clocale model for newlib is available.</p><p> 258 The library was updated to avoid including 259 <code class="filename"><unistd.h></code> in order 260 to reduce namespace pollution. 261</p><p>Debug Mode was improved for unordered containers. </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_480"></a><code class="constant">4.8</code></h3></div></div></div><p> 262 New random number engines and distributions. 263 Optimisations for random. 264</p><p>New --enable-libstdcxx-verbose configure option</p><p> 265 The --enable-libstdcxx-time configure option becomes unnecessary given a 266 sufficiently recent glibc. 267</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_490"></a><code class="constant">4.9</code></h3></div></div></div><p> Implementation of <code class="classname">regex</code> completed. </p><p> C++14 library and TS implementations are added. </p><p> <code class="function">copy_exception</code> deprecated. </p><p> <code class="classname">__gnu_cxx::array_allocator</code> deprecated. </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_51"></a><code class="constant">5</code></h3></div></div></div><p> 268 ABI transition adds new implementations of several components, using the 269 <code class="code">abi_tag</code> attribute and the <code class="code">__cxx11</code> inline 270 namespace to distinguish the new entities from the old ones. 271</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> 272 Use of the new or old ABI can be selected per-translation unit with the 273 <a class="xref" href="using_macros.html" title="Macros">Macros</a>. 274 </p></li><li class="listitem"><p> 275 New non-reference-counted <code class="classname">string</code> implementation. 276 </p></li><li class="listitem"><p> 277 New <code class="classname">list</code> implementation containing a new 278 data member in order to provide O(1) <code class="function">size()</code>. 279 </p></li><li class="listitem"><p> 280 New <code class="classname">ios_base::failure</code> implementation inheriting 281 from <code class="classname">system_error</code>. 282 </p></li></ul></div><p> 283 C++11 support completed (movable iostreams, new I/O manipulators, 284 Unicode conversion utilities, atomic operations for 285 <code class="classname">shared_ptr</code>, functions for notifying condition 286 variables and making futures ready at thread exit). 287</p><p> 288 Changed formatting of floating point types when 289 <code class="code">ios_base::fixed|ios_base::scientific</code> is set in a stream's 290 format flags. 291</p><p> Improved C++14 support and TS implementations. </p><p> New random number engines and distributions. </p><p> 292 GDB Xmethods for containers and <code class="classname">unique_ptr</code> added. 293</p><p> 294 <code class="classname">has_trivial_default_constructor</code>, 295 <code class="classname">has_trivial_copy_constructor</code> and 296 <code class="classname">has_trivial_copy_assign</code> deprecated. 297</p><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="api.rel_53"></a><code class="constant">5.3</code></h4></div></div></div><p> Experimental implementation of the C++ Filesystem TS added. </p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_61"></a><code class="constant">6</code></h3></div></div></div><p> C++14 support completed. </p><p> 298 Support for mathematical special functions (ISO/IEC 29124:2010) added. 299</p><p> 300 Assertions to check function preconditions can be enabled by defining the 301 <a class="link" href="using_macros.html" title="Macros"><span class="symbol">_GLIBCXX_ASSERTIONS</span> 302 macro</a>. 303 The initial set of assertions are a subset of the checks enabled by 304 the Debug Mode, but without the ABI changes and changes to algorithmic 305 complexity that are caused by enabling the full Debug Mode. 306</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_71"></a><code class="constant">7</code></h3></div></div></div><p> 307 The type of exception thrown by iostreams changed to the <code class="code">cxx11</code> 308 ABI version of <code class="classname">std::ios_base::failure</code>. 309</p><p> 310 Experimental C++17 support added, including most new library features. 311 The meaning of <code class="classname">shared_ptr<T[]></code> changed to 312 match the C++17 semantics. 313</p><p> 314 <a class="xref" href="using_macros.html" title="Macros">Macros</a> added. 315</p><p> 316 <code class="classname">has_trivial_default_constructor</code>, 317 <code class="classname">has_trivial_copy_constructor</code> and 318 <code class="classname">has_trivial_copy_assign</code> removed. 319</p><p> 320Calling a <code class="code">std::bind</code> result as volatile was deprecated for C++17. 321</p><p> Profile Mode was deprecated. </p><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="api.rel_72"></a><code class="constant">7.2</code></h4></div></div></div><p> 322 Library Fundamentals TS header 323 <code class="filename"><experimental/source_location></code> 324 added. 325</p></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="api.rel_73"></a><code class="constant">7.3</code></h4></div></div></div><p> 326 Including new C++14 or C++17 headers without a suitable <code class="option">-std</code> 327 no longer causes compilation to fail via <code class="literal">#error</code>. 328 Instead the header is simply empty and doesn't define anything. 329</p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_81"></a><code class="constant">8</code></h3></div></div></div><p> 330 The exceptions thrown by iostreams can now be caught by handlers for either 331 version of <code class="classname">std::ios_base::failure</code>. 332</p><p> 333 Improved experimental C++17 support. Headers 334 <code class="filename"><charconv></code> and 335 <code class="filename"><filesystem></code>. 336 Experimental implementation of the C++17 Filesystem library added. 337</p><p> 338 Experimental C++2a support 339 (<code class="function">to_address</code> and <code class="classname">endian</code>). 340</p><p> 341 AddressSanitizer annotations added to <code class="classname">std::vector</code> 342 to detect out-of-range accesses to the unused capacity of a vector. 343</p><p> 344 <code class="function">std::char_traits<char16_t>::to_int_type(u'\uFFFF')</code> 345 now returns <code class="literal">0xFFFD</code>, as <code class="literal">0xFFFF</code> is 346 used for <code class="function">std::char_traits<char16_t>::eof()</code>. 347</p><p> 348 The extension allowing arithmetic on 349 <code class="classname">std::atomic<void*></code> and types like 350 <code class="classname">std::atomic<R(*)()></code> was deprecated. 351</p><p> 352 The <code class="function">std::uncaught_exception</code> function was deprecated 353 for C++17 mode. 354</p><p> 355 The nested typedefs <span class="type">std::hash::result_type</span> and 356 <span class="type">std::hash::argument_type</span> were deprecated for C++17 mode. 357</p><p> 358 The deprecated iostream members <span class="type">ios_base::io_state</span>, 359 <span class="type">ios_base::open_mode</span>, <span class="type">ios_base::seek_dir</span>, and 360 <code class="function">basic_streambuf::stossc</code> were removed for C++17 mode. 361</p><p> 362 The non-standard C++0x <code class="function">std::copy_exception</code> function 363 was removed. 364</p><p> 365 For <code class="option">-std=c++11</code>, <code class="option">-std=c++14</code>, and 366 <code class="option">-std=c++17</code> modes the <code class="filename"><complex.h></code> 367 header no longer includes the C99 <code class="filename"><complex.h></code> 368 header. 369</p><p> 370 For the non-default <code class="option">--enable-symvers=gnu-versioned-namespace</code> 371 configuration, the shared library SONAME has been changed to 372 <code class="filename">libstdc++.so.8</code>. 373</p><p> 374 The extension allowing containers to be instantiated with an allocator 375 that doesn't match the container's value type is no longer allowed in 376 strict (<code class="option">-std=c++NN</code>) modes, only in 377 <code class="option">-std=gnu++NN</code> modes. 378</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_91"></a><code class="constant">9</code></h3></div></div></div><p> 379 C++17 header 380 <code class="filename"><memory_resource></code> 381 added. 382</p><p> 383 Experimental C++2a support improved, with new headers 384 <code class="filename"><bit></code> and 385 <code class="filename"><version></code> added. 386 Support for new character type <span class="type">char8_t</span> added 387 to <code class="classname">char_traits</code>, <code class="classname">basic_string</code>, 388 <code class="classname">numeric_limits</code>, 389 and relevant locale facets and type traits. 390</p><p> 391 Experimental implementation of the Networking TS library added, 392 with new headers 393 <code class="filename"><experimental/buffer></code>, 394 <code class="filename"><experimental/executor></code>, 395 <code class="filename"><experimental/internet></code>, 396 <code class="filename"><experimental/io_context></code>, 397 <code class="filename"><experimental/net></code>, 398 <code class="filename"><experimental/netfwd></code>, 399 <code class="filename"><experimental/socket></code>, 400 and 401 <code class="filename"><experimental/timer></code>. 402</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_101"></a><code class="constant">10</code></h3></div></div></div><p> Deprecated features removed: 403</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> Profile Mode </li><li class="listitem"><code class="classname">__gnu_cxx::array_allocator</code></li></ul></div><p> 404</p><p> 405 The non-standard <code class="function">std::__is_nullptr_t</code> type trait 406 was deprecated. 407</p><p> 408 The <code class="classname">std::packaged_task</code> constructors taking 409 an allocator argument are only defined for C++11 and C++14. 410</p><p> 411 Several members of <code class="classname">std::allocator</code> were removed 412 for C++20 mode. The removed functionality has been provided by 413 <code class="classname">std::allocator_traits</code> since C++11 and that should 414 be used instead. 415</p><p> 416 The type of the <code class="classname">std::iterator</code> base class of 417 <code class="classname">std::istreambuf_iterator</code> was changed to be 418 consistent for all <code class="option">-std</code> modes. 419 Before GCC 10.1 the base class had one type in C++98 mode and a 420 different type in C++11 and later modes. The type in C++98 mode 421 was changed to be the same as for C++11 and later. 422</p><p> 423 Experimental C++2a support improved, with new headers 424 <code class="filename"><concepts></code>, 425 <code class="filename"><ranges></code>, 426 <code class="filename"><compare></code>, 427 <code class="filename"><coroutine></code>, 428 <code class="filename"><numbers></code>, 429 <code class="filename"><span></code>, 430 and 431 <code class="filename"><stop_token></code> 432 added. 433</p><p> 434 The extension allowing containers to be instantiated with an allocator 435 that doesn't match the container's value type is no longer allowed in 436 C++20 mode, even in non-strict <code class="option">-std=gnu++20</code> mode. 437</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_111"></a><code class="constant">11</code></h3></div></div></div><p> 438 The <code class="option">--enable-cheaders=c_std</code> configuration 439 was deprecated. 440</p><p> 441 When compiling as C++20, the <code class="function">operator>></code> overloads 442 for extracting strings into character buffers only work with arrays, 443 not raw pointers. 444</p><p> 445 <code class="code">std::string::reserve(n)</code> will no longer reduce 446 the string's capacity. 447 Calling <code class="function">reserve()</code> with no arguments is equivalent 448 to <code class="function">shrink_to_fit()</code>, but is deprecated. 449 <code class="function">shrink_to_fit()</code> should be used instead. 450</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_121"></a><code class="constant">12</code></h3></div></div></div><p> 451The <code class="function">std::random_shuffle</code> algorithms are deprecated 452for C++14 and later. The C++11 <code class="function">std::shuffle</code> algorithm 453can be used instead. 454</p><p> 455The <code class="function">std::unexpected</code> function and related typedef and 456accessors for the unexpected handler are deprecated for C++11 and later. 457Dynamic exception specifications should be replaced with <code class="code">noexcept</code>. 458</p><p> 459C++98 adaptable function utilities 460(<code class="code">std::bind1st</code>, <code class="code">std::unary_function</code>, 461<code class="code">std::ptr_fun</code>, <code class="code">std::mem_fun_ref</code> etc.) 462were deprecated for C++11. 463<code class="code">std::iterator</code>, <code class="code">std::raw_storage_iterator</code>, 464<code class="code">get_temporary_buffer</code>, and <code class="code">std::not_fun</code> 465were deprecated for C++17. 466</p><p> 467Non-standard <code class="code">std::pair</code> constructors were deprecated. 468A non-standard default argument for 469<code class="code">vector<bool>::insert(const_iterator, const bool&)</code> 470was deprecated. 471</p><p> 472The <code class="literal">bitmap</code>, <code class="literal">mt</code>, and <code class="literal">pool</code> 473options for <code class="option">--enable-libstdcxx-allocator</code> were removed. 474For the <code class="literal">new</code> option, <code class="classname">std::allocator</code> 475no longer derives from <code class="classname">__gnu_cxx::new_allocator</code>; 476they both derive from <code class="classname">std::__new_allocator</code> instead. 477</p><p> 478<code class="function">std::condition_variable::wait</code> changed to be 479<code class="code">noexcept(false)</code> to allow thread cancellation exceptions to 480be thrown from <code class="function">pthread_cond_wait</code> without aborting 481the process. 482</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_123"></a><code class="constant">12.3</code></h3></div></div></div><p> 483Calling a <code class="code">std::bind</code> result as volatile is ill-formed for C++20 484and later. 485</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="abi.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="appendix_porting.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="backwards.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ABI Policy and Guidelines </td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> Backwards Compatibility</td></tr></table></div></body></html>