| <section xmlns="http://docbook.org/ns/docbook" version="5.0" |
| xml:id="status.iso.2017" xreflabel="Status C++ 2017"> |
| <?dbhtml filename="status_iso_cxx2017.html"?> |
| |
| <info><title>C++ 2017</title> |
| <keywordset> |
| <keyword>ISO C++</keyword> |
| <keyword>2017</keyword> |
| </keywordset> |
| </info> |
| |
| <para> |
| In this implementation the <literal>-std=gnu++17</literal> or |
| <literal>-std=c++17</literal> flag must be used to enable language |
| and library |
| features. See <link linkend="manual.intro.using.flags">dialect</link> |
| options. The pre-defined symbol |
| <constant>__cplusplus</constant> is used to check for the |
| presence of the required flag. |
| </para> |
| |
| <para> |
| This section describes the C++17 and library TS support in the GCC 9 series. |
| </para> |
| |
| <para> |
| The following table lists new library features that are included in |
| the C++17 standard. The "Proposal" column provides a link to the |
| ISO C++ committee proposal that describes the feature, while the "Status" |
| column indicates the first version of GCC that contains an implementation of |
| this feature (if it has been implemented). |
| The "SD-6 Feature Test" column shows the corresponding macro or header from |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations">SD-6: |
| Feature-testing recommendations for C++</link>. |
| </para> |
| |
| <table frame="all" xml:id="table.cxx17_status"> |
| <title>C++ 2017 Implementation Status</title> |
| |
| <tgroup cols="4" align="left" colsep="0" rowsep="1"> |
| <colspec colname="c1"/> |
| <colspec colname="c2"/> |
| <colspec colname="c3"/> |
| <colspec colname="c4"/> |
| <thead> |
| <row> |
| <entry>Library Feature</entry> |
| <entry>Proposal</entry> |
| <entry>Status</entry> |
| <entry>SD-6 Feature Test</entry> |
| </row> |
| </thead> |
| |
| <tbody> |
| |
| <row> |
| <?dbhtml bgcolor="#C8B0B0" ?> |
| <entry> |
| <code>constexpr std::hardware_{constructive,destructive}_interference_size</code> |
| </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0154r1.html"> |
| P0154R1 |
| </link> |
| </entry> |
| <entry align="center"> No </entry> |
| <entry> <code>__cpp_lib_hardware_interference_size >= 201603</code> </entry> |
| </row> |
| |
| <row> |
| <entry> Core Issue 1776: Replacement of class objects containing reference members</entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0137r1.html"> |
| P0137R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code>__cpp_lib_launder >= 201606</code> </entry> |
| </row> |
| |
| <row> |
| <entry>Wording for <code>std::uncaught_exceptions</code></entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/JTC1/sc22/WG21/docs/papers/2014/n4259.pdf"> |
| N4259 |
| </link> |
| </entry> |
| <entry align="center">6.1</entry> |
| <entry><code>__cpp_lib_uncaught_exceptions >= 201411</code></entry> |
| </row> |
| |
| <row> |
| <entry> C++17 should refer to C11 instead of C99 </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0063r3.html"> |
| P0063R3 |
| </link> |
| </entry> |
| <entry align="center"> 9.1 </entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <entry> Variant: a type-safe union for C++17 </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0088r3.html"> |
| P0088R3 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code>__has_include(<variant>)</code>, |
| <code>__cpp_lib_variant >= 201603</code> |
| (since 7.3, see Note 1) |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Library Fundamentals V1 TS Components: <code>optional</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html"> |
| P0220R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code>__has_include(<optional>)</code>, |
| <code>__cpp_lib_optional >= 201603</code> |
| (since 7.3, see Note 1) |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Library Fundamentals V1 TS Components: <code>any</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html"> |
| P0220R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code>__has_include(<any>)</code>, |
| <code>__cpp_lib_any >= 201603</code> |
| (since 7.3, see Note 1) |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Library Fundamentals V1 TS Components: <code>string_view</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html"> |
| P0220R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code>__has_include(<string_view>)</code>, |
| <code>__cpp_lib_string_view >= 201603</code> |
| (since 7.3, see Note 1) |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Library Fundamentals V1 TS Components: <code>memory_resource</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html"> |
| P0220R1 |
| </link> |
| </entry> |
| <entry align="center"> 9.1 </entry> |
| <entry> <code>__has_include(<memory_resource>)</code>, |
| <code>__cpp_lib_memory_resource >= 201603</code> |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Library Fundamentals V1 TS Components: <code>apply</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html"> |
| P0220R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code>__cpp_lib_apply >= 201603</code> </entry> |
| </row> |
| |
| <row> |
| <entry> Library Fundamentals V1 TS Components: <code>shared_ptr<T[]></code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html"> |
| P0220R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code>__cpp_lib_shared_ptr_arrays >= 201603</code> </entry> |
| </row> |
| |
| <row> |
| <entry> Library Fundamentals V1 TS Components: Searchers </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html"> |
| P0220R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code>__cpp_lib_boyer_moore_searcher >= 201603</code> </entry> |
| </row> |
| |
| <row> |
| <entry> Library Fundamentals V1 TS Components: Sampling </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html"> |
| P0220R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code>__cpp_lib_sample >= 201603</code> </entry> |
| </row> |
| |
| <row> |
| <entry> Constant View: A proposal for a <code>std::as_const</code> helper function template </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href=""> |
| P0007R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_as_const >= 201510 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Improving pair and tuple </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4387"> |
| N4387 |
| </link> |
| </entry> |
| <entry align="center"> 6.1 </entry> |
| <entry> N/A </entry> |
| </row> |
| |
| <row> |
| <entry> <code>make_from_tuple</code>: apply for construction </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0209r2.pdf"> |
| P0209R2 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_make_from_tuple >= 201606 </code></entry> |
| </row> |
| |
| <row> |
| <?dbhtml bgcolor="#C8B0B0" ?> |
| <entry> |
| Removing <code>auto_ptr</code>, <code>random_shuffle()</code>, |
| And Old <code><functional></code> Stuff |
| </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4190.htm"> |
| N4190 |
| </link> |
| </entry> |
| <entry align="center">No (kept for backwards compatibility)</entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <?dbhtml bgcolor="#C8B0B0" ?> |
| <entry> Deprecating Vestigial Library Parts in C++17 </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0174r2.html"> |
| P0174R2 |
| </link> |
| </entry> |
| <entry align="center"> No (kept for backwards compatibility)</entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <entry> Making <code>std::owner_less</code> more flexible </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0074r0.html"> |
| P0074R0 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_transparent_operators >= 201510 </code></entry> |
| </row> |
| |
| <row> |
| <entry> <code>std::addressof</code> should be constexpr </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0304r0.html#2296"> |
| LWG2296 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_addressof_constexpr >= 201603 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Safe conversions in <code>unique_ptr<T[]></code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4089.pdf"> |
| N4089 |
| </link> |
| </entry> |
| <entry align="center"> 6 </entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <entry> LWG 2228: Missing SFINAE rule in unique_ptr templated assignment </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4366.html"> |
| N4366 |
| </link> |
| </entry> |
| <entry align="center"> 6 </entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <entry> Re-enabling <code>shared_from_this</code></entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0033r1.html"> |
| P0033R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code>__cpp_lib_enable_shared_from_this >= 201603</code></entry> |
| </row> |
| |
| <row> |
| <entry> A proposal to add <code>invoke</code> function template </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4169.html"> |
| N4169 |
| </link> |
| </entry> |
| <entry align="center"> 6.1 </entry> |
| <entry><code> __cpp_lib_invoke >= 201411 </code></entry> |
| </row> |
| |
| <row> |
| <entry>TriviallyCopyable <code>reference_wrapper</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4277.html"> |
| N4277 |
| </link> |
| </entry> |
| <entry align="center"> 5.1 </entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <entry> Adopt <code>not_fn</code> from Library Fundamentals 2 for C++17 </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0005r4.html"> |
| P0005R4 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code>__cpp_lib_not_fn >= 201603</code></entry> |
| </row> |
| |
| <row> |
| <entry> Fixes for <code>not_fn</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0358r1.html"> |
| P0358R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <entry> Fixing a design mistake in the searchers interface in Library Fundamentals </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0253r1.pdf"> |
| P0253R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <entry> Extending memory management tools </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0040r3.html"> |
| P0040R3 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code>__cpp_lib_raw_memory_algorithms >= 201606L</code></entry> |
| </row> |
| |
| <row> |
| <entry> <code>shared_ptr::weak_type</code></entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0163r0.html"> |
| P0163R0 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_shared_ptr_weak_type >= 201606</code></entry> |
| </row> |
| |
| <row> |
| <entry>Transformation Trait Alias <code>void_t</code></entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/JTC1/sc22/WG21/docs/papers/2014/n3911.pdf"> |
| N3911 |
| </link> |
| </entry> |
| <entry align="center">6.1</entry> |
| <entry><code> __cpp_lib_void_t >= 201411</code></entry> |
| </row> |
| |
| <row> |
| <entry> Wording for <code>bool_constant</code>, revision 1 </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4389.html"> |
| N4389 |
| </link> |
| </entry> |
| <entry align="center">6.1</entry> |
| <entry><code> __cpp_lib_bool_constant >= 201505</code></entry> |
| </row> |
| |
| <row> |
| <entry> Adopt Type Traits Variable Templates from Library Fundamentals TS for C++17</entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0006r0.html"> |
| P0006R0 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_type_trait_variable_templates >= 201510 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Logical Operator Type Traits</entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0013r1.html"> |
| P0013R1 |
| </link> |
| </entry> |
| <entry align="center"> 6.1 </entry> |
| <entry><code> __cpp_lib_logical_traits >= 201510 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Adding [nothrow-]swappable traits </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0185r1.html"> |
| P0185R1 |
| </link> |
| </entry> |
| <entry align="center"> 7 (<code>__is_swappable</code> available since 6.1)</entry> |
| <entry><code> __cpp_lib_is_swappable >= 201603 </code></entry> |
| </row> |
| |
| <row> |
| <entry> <code>is_callable</code>, the missing INVOKE related trait</entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0077r2.html"> |
| P0077R2 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_is_callable >= 201603 </code></entry> |
| </row> |
| |
| <row> |
| <entry> has_unique_object_representations </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0258r2.html"> |
| P0258R2 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_has_unique_object_representations >= 201606 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Polishing <code><chrono></code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0092r1.html"> |
| P0092R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_chrono >= 201510 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Adding more constexpr to <code><chrono></code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0505r0.html"> |
| P0505R0 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_chrono >= 201611 </code> |
| (since 7.3, see Note 2) |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Constexpr for <code>std::char_traits</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0426r1.html"> |
| P0426R1 |
| </link> |
| </entry> |
| <entry align="center"> 8.1 </entry> |
| <entry><code> __cpp_lib_constexpr_char_traits >= 201611 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Integrating <code>std::string_view</code> and <code>std::string</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0254r2.pdf"> |
| P0254R2 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> </code></entry> |
| </row> |
| |
| <row> |
| <entry> Give 'std::string' a non-const '.data()' member function </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0272r1.html"> |
| P0272R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> </code></entry> |
| </row> |
| |
| <row> |
| <entry>Cleaning-up noexcept in the Library</entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4258.pdf"> |
| N4258 |
| </link> |
| </entry> |
| <entry align="center">6.1</entry> |
| <entry><code> __cpp_lib_allocator_traits_is_always_equal >= 201411 </code></entry> |
| </row> |
| |
| <row> |
| <entry>Contiguous Iterators </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4284.html"> |
| N4284 |
| </link> |
| </entry> |
| <entry align="center">N/A</entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <entry> Minimal incomplete type support for standard containers </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4510.html"> |
| N4510 |
| </link> |
| </entry> |
| <entry align="center"> 3.0 </entry> |
| <entry><code> __cpp_lib_incomplete_container_elements >= 201505 </code> |
| (since 6.2, see Note 2) |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Emplace return type </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0084r2.pdf"> |
| P0084R2 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry/> |
| </row> |
| |
| <row> |
| <entry>Improved insertion interface for unique-key maps</entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4279.html"> |
| N4279 |
| </link> |
| </entry> |
| <entry align="center"> 6.1 </entry> |
| <entry><code> __cpp_lib_map_try_emplace >= 201411</code>, |
| <code> __cpp_lib_unordered_map_try_emplace >= 201411</code> |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Splicing Maps and Sets </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0083r3.pdf"> |
| P0083R3 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_node_extract >= 201606 </code></entry> |
| </row> |
| |
| <row> |
| <entry>Non-member <code>size()</code> and more</entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4280.pdf"> |
| N4280 |
| </link> |
| </entry> |
| <entry align="center"> 6.1 </entry> |
| <entry><code> __cpp_lib_nonmember_container_access >= 201411 </code></entry> |
| </row> |
| |
| <row> |
| <entry> A Proposal to Add Constexpr Modifiers to <code>reverse_iterator</code>, <code>move_iterator</code>, <code>array</code> and Range Access </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0031r0.html"> |
| P0031R0 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_array_constexpr >= 201603 </code></entry> |
| </row> |
| |
| <row> |
| <?dbhtml bgcolor="#B0B0B0" ?> |
| <entry> The Parallelism TS Should be Standardized </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0024r2.html"> |
| P0024R2 |
| </link> |
| </entry> |
| <entry align="center"> 9.1 </entry> |
| <entry><code> __has_include(<execution>) </code>, |
| <code> __cpp_lib_execution >= 201603 </code>, |
| <code> __cpp_lib_parallel_algorithm >= 201603 </code> |
| (requires linking with <code>-ltbb</code>, see Note 3) |
| </entry> |
| </row> |
| |
| <row> |
| <entry> An algorithm to "clamp" a value between a pair of boundary values </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0025r0.html"> |
| P0025R0 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_clamp >= 201603 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Adopt Selected Library Fundamentals V2 Components for C++17 </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0295r0.pdf"> |
| P0295R0 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_gcd_lcm >= 201606 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Proposal to Introduce a 3-Argument Overload to <code>std::hypot</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0030r1.pdf"> |
| P0030R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_hypot >= 201603 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Mathematical Special Functions for C++17 </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0226r1.pdf"> |
| P0226R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_math_special_functions >= 201603 </code> |
| (see Note 4) |
| </entry> |
| </row> |
| |
| <row> |
| <entry>Adopt the File System TS for C++17 </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0218r1.html"> |
| P0218R1 |
| </link> |
| </entry> |
| <entry align="center"> 8.1 </entry> |
| <entry><code> __has_include(<filesystem>) </code>, |
| <code> __cpp_lib_filesystem >= 201603 </code> |
| (GCC 8.x requires linking with <code>-lstdc++fs</code>) |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Relative Paths for Filesystem</entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0219r1.html"> |
| P0219R1 |
| </link> |
| </entry> |
| <entry align="center"> 8.1 </entry> |
| <entry><code> __cpp_lib_filesystem >= 201606 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Adapting string_view by filesystem paths </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0392r0.pdf"> |
| P0392R0 |
| </link> |
| </entry> |
| <entry align="center"> 8.1 </entry> |
| <entry><code> __cpp_lib_filesystem >= 201606 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Directory Entry Caching for Filesystem </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0317r1.html"> |
| P0317R1 |
| </link> |
| </entry> |
| <entry align="center"> 8.1 </entry> |
| <entry><code> __cpp_lib_filesystem >= 201703 </code></entry> |
| </row> |
| |
| <row> |
| <entry> constexpr <code>atomic<T>::is_always_lock_free</code> </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0152r1.html"> |
| P0152R1 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_atomic_is_always_lock_free >= 201603 </code></entry> |
| </row> |
| |
| <row> |
| <entry>A proposal to add <code>shared_mutex</code> (untimed) (Revision 4)</entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4508.html"> |
| N4508 |
| </link> |
| </entry> |
| <entry align="center"> 6.1 </entry> |
| <entry><code> __cpp_lib_shared_mutex >= 201505 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Variadic <code>lock_guard</code> (Rev. 5) </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0156r2.html"> |
| P0156R2 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_scoped_lock >= 201703 </code></entry> |
| </row> |
| |
| <row> |
| <entry> A byte type definition </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0298r3.pdf"> |
| P0298R3 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry><code> __cpp_lib_byte >= 201603 </code> (since 7.3, see Note 2) |
| </entry> |
| </row> |
| |
| <row> |
| <?dbhtml bgcolor="#B0B0B0" ?> |
| <entry> Elementary string conversions </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0067r5.html"> |
| P0067R5 |
| </link> |
| </entry> |
| <entry align="center"> 8.1 (only integral types supported) </entry> |
| <entry><code> __has_include(<charconv>) </code> |
| <code> __cpp_lib_to_chars >= 201611 </code></entry> |
| </row> |
| |
| <row> |
| <entry> Homogeneous interface for variant, any and optional </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0032r3.pdf"> |
| P0032R3 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> |
| <code> __cpp_lib_any >= 201606 </code>, |
| <code> __cpp_lib_optional >= 201606 </code>, |
| <code> __cpp_lib_variant >= 201606 </code> |
| </entry> |
| </row> |
| |
| <row> |
| <entry> Making Optional Greater Equal Again </entry> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0307r2.pdf"> |
| P0307R2 |
| </link> |
| </entry> |
| <entry align="center"> 7.1 </entry> |
| <entry> <code> __cpp_lib_optional >= 201606 </code> </entry> |
| </row> |
| |
| </tbody> |
| </tgroup> |
| </table> |
| |
| <para> |
| Note 1: This feature is supported in GCC 7.1 and 7.2 but before GCC 7.3 the |
| <code>__cpp_lib</code> macro is not defined, and compilation will fail if the |
| header is included without using <option>-std</option> to enable C++17 support. |
| </para> |
| |
| <para> |
| Note 2: This feature is supported in older releases but the |
| <code>__cpp_lib</code> macro is not defined to the right value |
| (or not defined at all) until the version shown in parentheses. |
| </para> |
| |
| <para> |
| Note 3: The Parallel Algorithms have an external dependency on Intel TBB 2018 |
| or later. If the <filename class="headerfile"><execution></filename> |
| header is included then <code>-ltbb</code> must be used to link to TBB. |
| </para> |
| |
| <para> |
| Note 4: The mathematical special functions are enabled in C++17 mode from |
| GCC 7.1 onwards. For GCC 6.x or for C++11/C++14 define |
| <code>__STDCPP_WANT_MATH_SPEC_FUNCS__</code> to a non-zero value |
| and test for <code>__STDCPP_MATH_SPEC_FUNCS__ >= 201003L</code>. |
| </para> |
| |
| <table frame="all" xml:id="table.cxx17_ts_status"> |
| <title>C++ Technical Specifications Implementation Status</title> |
| |
| <tgroup cols="4" align="left" colsep="0" rowsep="1"> |
| <colspec colname="c1"/> |
| <colspec colname="c2"/> |
| <colspec colname="c3"/> |
| <colspec colname="c4"/> |
| <thead> |
| <row> |
| <entry>Paper</entry> |
| <entry>Title</entry> |
| <entry>Status</entry> |
| <entry>Comments</entry> |
| </row> |
| </thead> |
| |
| <tbody> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4076.html"> |
| N4076 |
| </link> |
| </entry> |
| <entry>A generalized callable negator</entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4273.htm"> |
| N4273 |
| </link> |
| </entry> |
| <entry>Uniform Container Erasure</entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4061.pdf"> |
| N4061 |
| </link> |
| </entry> |
| <entry>Greatest Common Divisor and Least Common Multiple</entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4066.htm"> |
| N4066 |
| </link> |
| </entry> |
| <entry>Delimited iterators</entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4282.pdf"> |
| N4282 |
| </link> |
| </entry> |
| <entry>The World's Dumbest Smart Pointer</entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4388.html"> |
| N4388 |
| </link> |
| </entry> |
| <entry>Const-Propagating Wrapper</entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4391.html"> |
| N4391 |
| </link> |
| </entry> |
| <entry> <code>make_array</code>, revision 4 </entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4502.pdf"> |
| N4502 |
| </link> |
| </entry> |
| <entry> Support for the C++ Detection Idiom, V2 </entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4519.pdf"> |
| N4519 |
| </link> |
| </entry> |
| <entry> Source-Code Information Capture </entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <?dbhtml bgcolor="#C8B0B0" ?> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4521.html"> |
| N4521 |
| </link> |
| </entry> |
| <entry> Merge Fundamentals V1 into V2 </entry> |
| <entry> |
| N (components from V1 are still in namespace |
| <code>fundamentals_v1</code>) |
| </entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://open-std.org/JTC1/SC22/WG21/docs/papers/2015/p0013r1.html"> |
| P0013R1 |
| </link> |
| </entry> |
| <entry>Logical Operator Type Traits (revision 1)</entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| <row> |
| <entry> |
| <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4531.html"> |
| N4531 |
| </link> |
| </entry> |
| <entry>std::rand replacement, revision 3</entry> |
| <entry>Y</entry> |
| <entry>Library Fundamentals 2 TS</entry> |
| </row> |
| |
| </tbody> |
| </tgroup> |
| </table> |
| |
| <section xml:id="iso.2017.specific" xreflabel="Implementation Specific"><info><title>Implementation Specific Behavior</title></info> |
| |
| <para>For behaviour which is also specified by previous standards, |
| see <link linkend="iso.1998.specific">C++ 1998/2003 Implementation |
| Specific Behavior</link> and <link linkend="iso.2011.specific">C++ |
| 2011 Implementation Specific Behavior</link>. This section only |
| documents behaviour which is new in the 2017 standard. |
| </para> |
| |
| <para> |
| <emphasis>20.5.1.2 [headers]</emphasis> |
| Whether names from Annex K are declared by C++ headers depends on |
| whether the underlying C library supports Annex K and declares the |
| names. For the GNU C library, there is no Annex K support and so |
| none of its names are declared by C++ headers. |
| </para> |
| |
| <para> |
| <emphasis>23.6.5 [optional.bad_optional_access]</emphasis> |
| <code>what()</code> returns <literal>"bad optional access"</literal>. |
| </para> |
| |
| <para> |
| <emphasis>23.7.3 [variant.variant]</emphasis> |
| <classname>variant</classname> supports over-aligned types. |
| </para> |
| |
| <para> |
| <emphasis>23.7.10 [variant.bad.access]</emphasis> |
| <code>what()</code> returns <literal>"Unexpected index"</literal>. |
| </para> |
| |
| <para> |
| <emphasis>23.12.5.2 [memory.resource.pool.options]</emphasis> |
| Let S equal <code>numeric_limits<size_t>::digits</code>. |
| The limit for maximum number of blocks in a chunk is given by |
| <inlineequation><mathphrase>2<superscript>N</superscript>-1</mathphrase></inlineequation>, |
| where N is <inlineequation><mathphrase>min(19, 3 + S/2)</mathphrase></inlineequation>. |
| The largest allocation size that will be allocated from a pool is |
| <inlineequation><mathphrase>2<superscript>22</superscript></mathphrase></inlineequation> |
| when <inlineequation><mathphrase>S > 20</mathphrase></inlineequation>, |
| otherwise 3072 when <inlineequation><mathphrase>S > 16</mathphrase></inlineequation>, |
| otherwise 768. |
| </para> |
| |
| <para> |
| <emphasis>23.12.6.1 [memory.resource.monotonic.buffer.ctor]</emphasis> |
| The default <code>next_buffer_size</code> is <code>128 * sizeof(void*)</code>. |
| The default growth factor is <code>1.5</code>. |
| </para> |
| |
| <para> |
| <emphasis>23.15.4.3 [meta.unary.prop]</emphasis> |
| The predicate condition for |
| <code>has_unique_object_representations</code> is true for all scalar |
| types except floating point types. |
| </para> |
| |
| <para> |
| <emphasis>23.19.3 [execpol.type], |
| 28.4.3 [algorithms.parallel.exec]</emphasis> |
| There are no implementation-defined execution policies. |
| </para> |
| |
| <para> |
| <emphasis>24.4.2 [string.view.template]</emphasis> |
| <classname>basic_string_view<C, T>::iterator</classname> is |
| <code>C*</code> and |
| <classname>basic_string_view<C, T>::const_iterator</classname> is |
| <code>const C*</code>. |
| </para> |
| |
| |
| <para> |
| <emphasis>28.4.3 [algorithms.parallel.exec]</emphasis> |
| Threads of execution created by <classname>std::thread</classname> |
| provide concurrent forward progress guarantees, so threads of execution |
| implicitly created by the library will provide parallel forward |
| progress guarantees. |
| </para> |
| |
| <para> |
| <emphasis>29.4.1 [cfenv.syn]</emphasis> |
| The effects of the <filename><cfenv></filename> functions |
| depends on whether the <code>FENV_ACCESS</code> pragma is supported, |
| and on the C library that provides the header. |
| </para> |
| |
| <para> |
| <emphasis>29.6.9 [c.math.rand]</emphasis> |
| Whether the <function>rand</function> function may introduce data |
| races depends on the target C library that provides the function. |
| </para> |
| |
| <para> |
| <emphasis>29.9.5 [sf.cmath]</emphasis> |
| The effect of calling the mathematical special functions with large |
| inputs should be documented here. |
| </para> |
| |
| <para> |
| <emphasis>30.10.2.1 [fs.conform.9945]</emphasis> |
| The behavior of the filesystem library implementation will depend on |
| the target operating system. Some features will not be supported |
| on some targets. |
| </para> |
| |
| <para> |
| <emphasis>30.10.5 [fs.filesystem.syn]</emphasis> |
| The clock used for file times is an unspecified type |
| with a signed 64-bit representation, capable of representing |
| timestamps with nanosecond resolution. The clock's epoch is |
| unspecified, but is not the same as the system clock's epoch. |
| </para> |
| |
| <para> |
| <emphasis>30.10.7.1 [fs.path.generic]</emphasis> |
| dot-dot in the root-directory refers to the root-directory itself. |
| On Windows, a drive specifier such as <code>"C:"</code> or |
| <code>"z:"</code> is treated as a root-name. On Cygwin, a path |
| that begins with two successive directory separators is a |
| root-name. Otherwise (for POSIX-like systems other than Cygwin), |
| the implementation-defined root-name is an unspecified string |
| which does not appear in any pathnames. |
| </para> |
| |
| <para> |
| <emphasis>30.10.10.1 [fs.enum.path.format]</emphasis> |
| The character sequence is always interpreted in the native pathname |
| format. |
| </para> |
| |
| <para> |
| <emphasis>30.10.15.4 [fs.op.file_size]</emphasis> |
| If <code>!is_regular_file(p)</code>, an error is reported. |
| </para> |
| |
| |
| </section> |
| |
| </section> |
