C++20

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

C++20 is the name for the revision of the ISO/IEC standard for the C++ programming language following C++17.[1] The standard became technically finalized[2] by WG21 at the meeting in Prague in February 2020.[3] C++20 is currently undergoing final editorial work, after a draft was approved on 4th September 2020.[4][5]

C++20 adds more new major features than C++14 or C++17.[6] Below is a partial list of changes that have been accepted into or have been discussed for inclusion into C++20.[7]

New features[edit]

C++20 introduced many new features. The following lists may be incomplete.

Language[edit]

  • concepts,[8] with terse syntax[9]
  • modules[10]
  • designated initializers[11] (based on the C99 feature, and common G++ extension)
  • [=, this] as a lambda capture[12]
  • template parameter lists on lambdas[13]
  • three-way comparison using the "spaceship operator", operator <=>
  • initialization of an additional variable within a range-based for statement[14]
  • lambdas in unevaluated contexts[15][16]
  • default constructible and assignable stateless lambdas[15][17]
  • allow pack expansions in lambda init-capture[15][18]
  • string literals as template parameters[15][19]
  • removing the need for typename in certain circumstances[20]
  • new standard attributes [[no_unique_address]],[21] [[likely]] and [[unlikely]][22]
  • conditional explicit, allowing the explicit modifier to be contingent on a boolean expression[23]
  • expanded constexpr: virtual functions,[24] union,[25] try and catch,[26] dynamic_cast and typeid,[27] std::pointer_traits[28]
  • immediate functions using the new consteval keyword[29]
  • signed integers are now defined to be represented using two's complement (signed integer overflow remains undefined behavior)[30]
  • a revised memory model[31]
  • various improvements to structured bindings (interaction with lambda captures, static and thread_local storage duration)[32][33]
  • coroutines[34]
  • using on scoped enums[35]
  • constinit keyword[36]

Library[edit]

  • ranges (The One Ranges Proposal)[37]
  • std::make_shared and std::allocate_shared for arrays[38]
  • atomic smart pointers (such as std::atomic<shared_ptr<T>> and std::atomic<weak_ptr<T>>)[39]
  • std::to_address to convert a pointer to a raw pointer[40]
  • calendar and time-zone additions to <chrono>[41]
  • std::span, providing a view to a contiguous array (analogous to std::string_view but span can mutate the referenced sequence)[42]
  • <version> header[43]
  • std::bit_cast<> for type casting of object representations, with less verbosity than memcpy() and more ability to exploit compiler internals[44]
  • feature test macros[45]
  • various constexpr library bits[46]
  • smart pointer creation with default initialization[47]
  • std::map::contains method[48]
  • bit operations, such as leading/trailing zero/one count,[49] and log2 operations[50][51][52]
  • std::bind_front[53]

Deprecation[edit]

  • Use of comma operator in subscript expressions has been deprecated[54]
  • (most of) volatile has been deprecated[55]

New (and changed) keywords[edit]

Many new keywords added (and the new "spaceship operator", operator <=>), such as concept, constinit,[36] consteval, co_await, co_return, co_yield, requires (plus changed meaning for export), and char8_t.[56] And explicit can take an expression since C++20.[57] Most of the uses of the volatile keyword have been deprecated.[55]

In addition to keywords, there are identifiers with special meaning, including new import and module.

New attributes in C++20: [[likely]], [[unlikely]], and [[no_unique_address]][58]

Removed features[edit]

C++20 also removed some features.[59]

  • The C-derived headers <ccomplex>, <ciso646>, <cstdalign>, <cstdbool> and <ctgmath> were removed, as they serve no purpose in C++. (The corresponding <*.h> headers remain, for compatibility with C.)
  • The use of throw() as an exception specification was removed.
  • Some previously deprecated library features were removed, including std::uncaught_exception, std::raw_storage_iterator, std::is_literal_type, std::is_literal_type_v, std::result_of and std::result_of_t.

History of changes[edit]

Changes applied to the C++20 working draft in July 2017 (Toronto) include:[60]

  • concepts
  • designated initializers
  • [=, this] as a lambda capture
  • template parameter lists on lambdas
  • std::make_shared and std::allocate_shared for arrays

Changes applied to the C++20 working draft in the fall meeting in November 2017 (Albuquerque) include:[61][62]

  • three-way comparison using the "spaceship operator", operator <=>
  • initialization of an additional variable within a range-based for statement
  • lambdas in unevaluated contexts
  • default constructible and assignable stateless lambdas
  • allow pack expansions in lambda init-capture
  • string literals as template parameters
  • atomic smart pointers (such as std::atomic<shared_ptr<T>> and std::atomic<weak_ptr<T>>)
  • std::to_address to convert a pointer to a raw pointer

Changes applied to the C++20 working draft in March 2018 (Jacksonville) include:[63]

  • removing the need for typename in certain circumstances
  • new standard attributes [[no_unique_address]], [[likely]] and [[unlikely]]
  • calendar and time-zone additions to <chrono>
  • std::span, providing a view to a contiguous array (analogous to std::string_view but span can mutate the referenced sequence)
  • <version> header

Changes applied to the C++20 working draft in the summer meeting in June 2018 (Rapperswil) include:[64]

  • contracts (later deferred to a later standard)[65]
  • feature test macros
  • bit-casting of object representations, with less verbosity than memcpy() and more ability to exploit compiler internals
  • conditional explicit, allowing the explicit modifier to be contingent on a boolean expression
  • constexpr virtual functions

Changes applied to the C++20 working draft in the fall meeting in November 2018 (San Diego) include:

  • ranges (The One Ranges Proposal)
  • concept terse syntax
  • constexpr union, try and catch, dynamic_cast, typeid and std::pointer_traits.
  • various constexpr library bits
  • immediate functions using the new consteval keyword
  • signed integers are now defined to be represented using two's complement (signed integer overflow remains undefined behavior)
  • refinements of the contracts facility (access control in contract conditions)[66] (see list of features deferred to a later standard)
  • a revised memory model
  • Smart pointer creation with default initialization

Changes applied to the C++20 working draft in the winter meeting in February 2019 (Kona) include:[67][68]

  • coroutines
  • modules
  • various improvements to structured bindings (interaction with lambda captures, static and thread_local storage duration)

Changes applied to the C++20 working draft in the summer meeting in July 2019 (Cologne) include:[69][70][71]

  • contracts were removed (see list of features deferred to a later standard)[72]
  • use of comma operator in subscript expressions has been deprecated[73]
  • constexpr additions (trivial default initialization,[74] unevaluated inline-assembly[75])
  • using scoped enums[76]
  • various changes to the spaceship operator[77][78]
  • DR: minor changes to modules[79]
  • constinit keyword
  • changes to concepts (removal of -> Type return-type-requirements[80])
  • (most of) volatile has been deprecated[55]
  • DR: [[nodiscard]] effects on constructors[81]
  • The new standard library concepts will not use PascalCase (rather standard_case, as the rest of the standard library)[82]
  • text formatting[83][84] (chrono integration,[85] corner case fixes[86])
  • bit operations[87]
  • constexpr INVOKE[88]
  • math constants[89]
  • consistency additions to atomics (std::atomic_ref<T>,[90] std::atomic<std::shared_ptr<T>>[91])
  • add the <=> operator to the standard library[92]
  • header units for the standard library[93]
  • synchronization facilities[94] (merged from: Efficient atomic waiting and semaphores,[95] latches and barriers,[96] Improving atomic_flag,[97] Don't Make C++ Unimplementable On Small CPUs[98])
  • std::source_location[99]
  • constexpr containers (std::string,[100] std::vector[101])
  • std::stop_token and joining thread (std::jthread)[102]

Changes applied during the NB comment resolution in the fall meeting in November 2019 (Belfast) include:[103][104][105]

  • Class Types in Non-Type Template Parameters (NTTP): The restriction of no user-defined operator== allowed has been removed as the meaning of template argument equality has been divorced from operator==.[106] This allows also for array members in class-type NTTP.
  • Floating-point types,[107] pointers and references and unions and union-like classes (class types containing anonymous unions) are now allowed as NTTP.
  • Function identity now also includes trailing requires-clauses (P1971)
  • Constrained non-template functions have been removed
  • <compare> is now available in freestanding implementations[108]
  • std::spans typedef was changed from index_type to size_type to be consistent with the rest of the standard library[109]
  • Concept traits have been renamed to follow the renaming of the concepts as a result from the Cologne meeting
  • Several fixes and additions to ranges (P1456R1: Move-only views,[110] P1391R4: Range constructor for std::string_view (constructor from iterator-pair of characters),[111] P1394R4: Range constructor for std::span<ref>,[112] P1870R1: forwarding-range<T> is too subtle[113])
  • Initialization for std::atomic<T> has been changed to make it work with default and list initialization,[114] std::latch and std::barrier can now report the maximum number of threads that the implementation supports through the new member function max()
  • std::weak_equality and std::strong_equality have been removed as they are not used anymore
  • Algorithms in <numeric> have been made constexpr
  • Missing feature-test macros for new or changed features of C++20 have been added[115]

Features published as Technical Specifications[edit]

Features deferred to a later standard[edit]

  • Contracts – a new study group (SG21) has been formed to work on a new proposal[120]
  • Reflection[121][122]
  • Metaclasses[123]
  • Executors[124]
  • Networking extensions,[125][126] including async, basic I/O services, timers, buffers and buffer-oriented streams, sockets, and Internet protocols (blocked by executors)
  • Properties[127]
  • Extended futures[128]

Compiler support[edit]

Developers of major compilers have prepared for the final C++20 standard by implementing experimental support for various features from the C++20 drafts.

  • Clang has partial C++20 support that can be enabled with the option -std=c++20 (version 10 and later) or -std=c++2a (version 9 and earlier).[129]
  • EDG eccp started implementing C++20 features in version 5.0 and as of version 6.1 supports most C++20 core language features.[130]
  • GCC added partial, experimental C++20 support in 2017[131] in version 8 through the option -std=c++2a. Like Clang, GCC replaced this option with -std=c++20 in version 10. It also has an option to enable GNU extensions in addition to the experimental C++20 support, -std=gnu++20.[132]
  • Microsoft Visual Studio supports some C++20 features through its std:c++latest option. An option /std:c++20 to enable C++20 mode is expected as soon as the compiler is C++20 feature complete.[133]

See also[edit]

References[edit]

  1. ^ "The Standard". isocpp.org. Retrieved 7 September 2020.
  2. ^ Sutter, Herb (2019-10-01). "P1000R3: C++ IS schedule" (PDF). Retrieved 2020-02-13.
  3. ^ Dusíková, Hana (2019-11-06). "N4817: 2020 Prague Meeting Invitation and Information" (PDF). Retrieved 2020-02-13.
  4. ^ "Current Status". isocpp.org. Retrieved 7 September 2020.
  5. ^ "C++20 Approved -- Herb Sutter". isocpp.org. Retrieved 8 September 2020.
  6. ^ "Why does the C++ standard ship every three years?".
  7. ^ "P0592R0: To boldly suggest an overall plan for C++20".
  8. ^ "P0606R0: Concepts Are Ready" (PDF).
  9. ^ "P1141R1 - Yet another approach for constrained declarations".
  10. ^ "N4720: Working Draft, Extensions to C++ for Modules" (PDF).
  11. ^ Tim Shen; Richard Smith. "Designated Initialization Wording".
  12. ^ Thomas Köppe. "Allow lambda capture [=, this]".
  13. ^ "Familiar template syntax for generic lambdas".
  14. ^ "Range-based for statements with initializer".
  15. ^ a b c d "Trip Report: C++ Standards Meeting in Albuquerque, November 2017". There's Waldo!. 2017-11-20. Retrieved 2017-12-11.
  16. ^ "Wording for lambdas in unevaluated contexts" (PDF).
  17. ^ "Default constructible and assignable stateless lambdas" (PDF).
  18. ^ "Pack expansion in lambda init-capture". www.open-std.org. Retrieved 2017-12-11.
  19. ^ "String literals as non-type template parameters" (PDF).
  20. ^ Nina Ranns; Daveed Vandevoorde. "Down with typename!".
  21. ^ "Language support for empty objects".
  22. ^ "Proposed wording for likely and unlikely attributes (Revision 5)".
  23. ^ "explicit(bool)". www.open-std.org. Retrieved 2018-11-13.
  24. ^ "Allowing Virtual Function Calls in Constant Expressions". www.open-std.org. Retrieved 2019-03-11.
  25. ^ "P1330R0 - Changing the active member of a union inside constexpr".
  26. ^ "P1002R0 - Try-catch blocks in constexpr functions" (PDF).
  27. ^ "P1327R0 - Allowing dynamic_cast, polymorphic typeid in Constant Expressions".
  28. ^ "P1006R1 - Constexpr in std::pointer_traits" (PDF).
  29. ^ "P1073R2 - Immediate functions".
  30. ^ "P1236R0: Alternative Wording for P0907R4 Signed Integers are Two's Complement".
  31. ^ "P0668R4: Revising the C++ memory model".
  32. ^ "P1091R1: Extending structured bindings to be more like variable declarations". www.open-std.org. Retrieved 2019-02-24.
  33. ^ "P1091R2: Extending structured bindings to be more like variable declarations". www.open-std.org. Retrieved 2019-02-24.
  34. ^ "N4649: Working Draft, Technical Specification on C++ Extensions for Coroutines" (PDF).
  35. ^ "P1099R5: Using Enum". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  36. ^ a b "P1143R2: Adding the constinit keyword". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  37. ^ "P0896R3" (PDF).
  38. ^ "Extending make_shared to Support Arrays".
  39. ^ Meredith, Alisdair; Sutter, Herb. "Revising atomic_shared_ptr for C++20". JTC1/SC22/WG21 - The C++ Standards Committee - ISOCPP. ISO. Retrieved 27 December 2018.
  40. ^ "Utility to convert a pointer to a raw pointer".
  41. ^ Howard E. Hinnant; Tomasz Kamiński. "Extending <chrono> to Calendars and Time Zones".
  42. ^ Neil MacIntosh; Stephan T. Lavavej. "span: bounds-safe views for sequences of objects".
  43. ^ Alan Talbot. "<version>".
  44. ^ "Bit-casting object representations". www.open-std.org. Retrieved 2018-11-10.
  45. ^ "Integrating feature-test macros into the C++ WD". www.open-std.org. Retrieved 2018-11-10.
  46. ^ "P1032R1 - Misc constexpr bits".
  47. ^ "Smart pointer creation with default initialization".
  48. ^ "std::map::contains - cppreference.com". en.cppreference.com. Retrieved 2020-05-12.
  49. ^ "P0553R4: Bit operations". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  50. ^ "P0556R3: Integral power-of-2 operations". www.open-std.org. 2018-06-06. Retrieved 2020-08-08.
  51. ^ "P1355R2 Exposing a narrow contract for ceil2". www.open-std.org. 2019-06-11. Retrieved 2020-08-08.
  52. ^ "On the names of low-level bit manipulation functions" (PDF). www.open-std.org. 2020-02-11. Retrieved 2020-08-08.
  53. ^ Tomasz Kamiński (2017-11-09). "Simplified partial function application".
  54. ^ "P1161R2: Deprecate uses of the comma operator in subscripting expressions". www.open-std.org. Retrieved 2019-07-20.
  55. ^ a b c "P1152R4: Deprecating volatile". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  56. ^ "C++ keywords - cppreference.com". en.cppreference.com. Retrieved 2019-08-04.
  57. ^ "explicit specifier - cppreference.com". en.cppreference.com. Retrieved 2019-08-04.
  58. ^ "attribute specifier sequence(since C++11) - cppreference.com". en.cppreference.com. Retrieved 2019-08-04.
  59. ^ "Working Draft, Standard for Programming Language C++ (Annex C, §C.1)" (PDF).
  60. ^ Herb Sutter. "Trip report: Summer ISO C++ standards meeting (Toronto)".
  61. ^ Herb Sutter. "Trip report: Fall ISO C++ standards meeting (Albuquerque)".
  62. ^ Smith, Richard; Perchik, Dawn; Köppe, Thomas. "N4714 Editors' Report -- Programming Languages -- C++". C++ standards drafts. GitHub. Retrieved 27 December 2018.
  63. ^ Botond Ballo. "Trip Report: C++ Standards Meeting in Jacksonville, March 2018".
  64. ^ Herb Sutter. "Trip report: Summer ISO C++ standards meeting (Rapperswil)".
  65. ^ "Support for contract based programming in C++". www.open-std.org. Retrieved 2018-11-10.
  66. ^ "P1289R0 - Access control in contract conditions" (PDF).
  67. ^ "r/cpp - 2019-02 Kona ISO C++ Committee Trip Report (C++20 design is complete; Modules in C++20; Coroutines in C++20; Reflection TS v1 published; work begins on a C++ Ecosystem Technical Report)". reddit. Retrieved 2019-02-24.
  68. ^ "Trip report: Winter ISO C++ standards meeting (Kona)". Sutter's Mill. 2019-02-23. Retrieved 2019-02-24.
  69. ^ "r/cpp - 2019-07 Cologne ISO C++ Committee Trip Report — 🚀 The C++20 Eagle has Landed 🚀 (C++20 Committee Draft shipped; Contracts Moved From C++20 to a Study Group; 'std::format' in C++20; C++20 Synchronization Library)". reddit. Retrieved 2019-09-15.
  70. ^ Botond Ballo. "Trip Report: C++ Standards Meeting in Cologne, July 2019".
  71. ^ Sutter, Herb. "Trip report: Summer ISO C++ standards meeting (Cologne)".
  72. ^ Josuttis, Nicolai. "P1823R0: Remove Contracts from C++20" (PDF).
  73. ^ "P1161R2: Deprecate uses of the comma operator in subscripting expressions". www.open-std.org. Retrieved 2019-07-20.
  74. ^ "Permitting trivial default initialization in constexpr contexts" (PDF).
  75. ^ "P1668R1: Enabling Constexpr Intrinsics By Permitting Unevaluated inline-asm in Constexpr Functions". www.open-std.org. Retrieved 2019-07-20.
  76. ^ "P1099R5: Using Enum". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  77. ^ "P1186R3: When do you actually use <=>?". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  78. ^ "P1630R1: Spaceship needs a tune-up". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  79. ^ "P1766R1: Mitigating minor modules maladies". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  80. ^ "P1452R2: On the non-uniform semantics of return-type-requirements". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  81. ^ "P1771R1: nodiscard for constructors" (PDF). www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  82. ^ "P1754R1: Rename concepts to standard_case for C++20, while we still can" (PDF). www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  83. ^ "P0645R10: Text Formatting". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  84. ^ "std::format in C++20". www.zverovich.net. 2019-07-23. Retrieved 2019-09-15.
  85. ^ "P1361R2: Integration of chrono with text formatting" (PDF). www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  86. ^ "P1652R1: Printf corner cases in std::format". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  87. ^ "P0553R4: Bit operations". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  88. ^ "P1965R2: constexpr INVOKE". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  89. ^ "P0631R8: Math Constants" (PDF). www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  90. ^ "P1643R1: Add wait/notify to atomic_ref<T>". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  91. ^ "P1664R0: Add wait/notify to atomic<shared_ptr<T>>". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  92. ^ "P1614R2: The Mothership has Landed - Adding <=> to the Library". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  93. ^ "P1502R1: Standard library header units for C++20". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  94. ^ "P1135R6: The C++20 Synchronization Library". www.open-std.org. 2019-07-20. Retrieved 2019-07-20.
  95. ^ "P0514R4: Efficient concurrent waiting for C++20" (PDF).
  96. ^ "P0666R2: Revised Latches and Barriers for C++20" (PDF).
  97. ^ "P0995R1: Improving atomic_flag".
  98. ^ "P1285R0: Don't Make C++ Unimplementable On Small CPUs".
  99. ^ "P1208R6: Adopt source_location from Library Fundamentals V3 for C++20" (PDF).
  100. ^ "P0980R1: Making std::string constexpr" (PDF).
  101. ^ "P1004R2: Making std::vector constexpr" (PDF).
  102. ^ "P0660R10: Stop Token and Joining Thread" (PDF).
  103. ^ "r/cpp - 2019-11 Belfast ISO C++ Committee Trip Report — Started Processing Feedback on the C++20 Committee Draft; ABI Review Group Formed". reddit. Retrieved 2019-11-09.
  104. ^ Sutter, Herb (2019-11-09). "Trip report: Autumn ISO C++ standards meeting (Belfast)". Sutter's Mill. Retrieved 2019-11-09.
  105. ^ botondballo (2019-11-15). "Trip Report: C++ Standards Meeting in Belfast, November 2019". There's Waldo!. Retrieved 2019-11-24.
  106. ^ "P1907R0: Inconsistencies with non-type template parameters". www.open-std.org. 2019-10-07. Retrieved 2019-11-09.
  107. ^ "P1714: NTTP are incomplete without float, double, and long double! (Revision 1)". www.open-std.org. 2019-07-19. Retrieved 2019-11-09.
  108. ^ "P1855R=: Make <compare> freestanding". www.open-std.org. 2019-10-05. Retrieved 2019-11-09.
  109. ^ "P1872R0: span should have size_type not index_type" (PDF). www.open-std.org. 2019-09-16. Retrieved 2019-11-09.
  110. ^ "P1456: Move-only views" (PDF). www.open-std.org. 2019-01-25. Retrieved 2019-11-09.
  111. ^ "P1391: Range constructor for std::string_view" (PDF). www.open-std.org. Retrieved 2019-11-09.
  112. ^ "P1394: Range constructor for std::span" (PDF). www.open-std.org. 2019-08-02. Retrieved 2019-11-09.
  113. ^ "P1870R1: forwarding-range<T> is too subtle". www.open-std.org. Retrieved 2019-11-09.
  114. ^ "P0883: Fixing Atomic Initialization" (PDF). www.open-std.org. 2018-06-05. Retrieved 2019-11-09.
  115. ^ "Missing feature-test macros 2018-2019". www.open-std.org. 2019-10-06. Retrieved 2019-11-09.
  116. ^ "C++ Extensions for Parallelism Version 2".
  117. ^ "Task Blocks".
  118. ^ "C++ Extensions for Networking".
  119. ^ "C++ Extensions for Reflection".
  120. ^ Sutter, Herb (2019-07-20). "Trip report: Summer ISO C++ standards meeting (Cologne)". Sutter's Mill. Retrieved 2019-07-21.
  121. ^ "Reflections on the reflection proposals - Meeting C++". meetingcpp.com. Retrieved 2017-06-30.
  122. ^ "Static reflection". www.open-std.org. Retrieved 2018-11-10.
  123. ^ Herb Sutter. "Metaclasses" (PDF).
  124. ^ "A Unified Executors Proposal for C++". www.open-std.org. Retrieved 2019-02-24.
  125. ^ "N4771: Working Draft, C++ Extensions for Networking" (PDF).
  126. ^ "ISO/IEC TS 19216:2018 Programming Languages -- C++ Extensions for Networking".
  127. ^ "A General Property Customization Mechanism". www.open-std.org. Retrieved 2019-02-24.
  128. ^ "A Unified Futures Proposal for C++".
  129. ^ https://clang.llvm.org/cxx_status.html
  130. ^ https://en.cppreference.com/w/cpp/compiler_support
  131. ^ https://gcc.gnu.org/legacy-ml/gcc-patches/2017-07/msg01234.html
  132. ^ https://gcc.gnu.org/projects/cxx-status.html
  133. ^ https://github.com/MicrosoftDocs/cpp-docs/blob/master/docs/overview/cpp-conformance-improvements.md

External links[edit]

  • JTC1/SC22/WG21 – the ISO/IEC C++ Standard Working Group (a.k.a. the C++ Standards Committee)
  • Ranges (range-v3) github repository, by Eric Niebler