C23 (C standard revision) explained

C23, formally ISO/IEC 9899:2024, is the current open standard for the C programming language, which supersedes C17 (standard ISO/IEC 9899:2018).^[1] It was started in 2016 informally as C2x,^[2] and was published on October 31, 2024.^[3] The freely available draft most similar to the one published is document N3220 (see Available texts, below). The first WG14 meeting for the C2x draft was held in October 2019,^[4] virtual remote meetings were held in 2020 due to the COVID-19 pandemic, then various teleconference meetings continued to occur through 2024.

In C23, the value of __STDC_VERSION__ changes from 201710L to 202311L. The common names "C17" and "C23" reflect these values, which are frozen prior to final adoption, rather than the years in the ISO standards identifiers (9899:2018 and 9899:2024).

Features

Changes integrated into the latest working draft of C23 are listed below.^[5]

Standard Library

New functions

• Add memset_explicit function in <[[string.h]]> to erase sensitive data, where memory store must always be performed regardless of optimizations.^[6]
• Add [[memccpy]] function in <string.h> to efficiently concatenate strings – similar to POSIX and SVID C extensions.^[7]
• Add [[strdup]] and strndup functions in <string.h> to allocate a copy of a string – similar to POSIX and SVID C extensions.^[8]
• Add memalignment function in <[[stdlib.h]]> to determine the byte alignment of a pointer.^[9]
• Add bit utility functions / macros / types in new header <[[stdbit.h]]> to examine many integer types. All start with stdc_ to minimize conflict with legacy code and 3rd party libraries.^[10]
  • In the following, replace * with uc, us, ui, ul, ull for five function names, or blank for a type-generic macro.^[10]
  • Add stdc_count_ones* and stdc_count_zeros* to count number of 1 or 0 bits in value.^[10]
  • Add stdc_leading_ones* and stdc_leading_zeros* to count leading 1 or 0 bits in value.^[10]
  • Add stdc_trailing_ones* and stdc_trailing_zeros* to count trailing 1 or 0 bits in value.^[10]
  • Add stdc_first_leading_one* and stdc_first_leading_zero* to find first leading bit with 1 or 0 in value.^[10]
  • Add stdc_first_trailing_one* and stdc_first_trailing_zero* to find first trailing bit with 1 or 0 in value.^[10]
  • Add stdc_has_single_bit* to determine if value is an exact power of 2 (return true if and only if there is a single 1 bit).^[10]
  • Add stdc_bit_floor* to determine the largest integral power of 2 that is not greater than value.^[10]
  • Add stdc_bit_ceil* to determine the smallest integral power of 2 that is not less than value.^[10]
  • Add stdc_bit_width* to determine number of bits to represent a value.^[10]
• Add timegm function in <[[time.h]]> to convert time structure into calendar time value - similar to function in glibc and musl libraries.^[11]
• New <[[math.h]]> functions based on IEEE 754-2019 recommendations, such as trigonometry functions operating on units of

\pi x and exp10.^[12]

Existing functions

• Add %b binary conversion specifier to printf function family.^[13]
• Add %b binary conversion specifier to scanf function family.^[13]
• Add 0b and 0B binary conversion support to strtol and wcstol function families.^[13]
• Make the functions [[bsearch]], [[bsearch|bsearch_s]], [[memchr]], [[strchr]], [[strpbrk]], [[strrchr]], [[strstr]], and their wide counterparts [[wmemchr]], [[wcschr]], [[wcspbrk]], [[wcsrchr]], [[wcsstr]] return a const qualified object if one was passed to them.^[14]

Preprocessor

• Add and directives,^[15] which are essentially equivalent to and . Both directives were added to standard and GCC 12.^[16]
• Add directive for binary resource inclusion and allowing the availability of a resource to be checked by preprocessor directives.^[17]
• Add directive for diagnostics.^[18]
• Add allowing the availability of a header to be checked by preprocessor directives.^[19]
• Add allowing the availability of an attribute to be checked by preprocessor directives.^[20] (see " compatibility" group for new attribute feature)
• Add functional macro for variadic macros which expands to its argument only if a variadic argument has been passed to the containing macro.^[21]

Types

• Add, a null pointer type.
• Add and types for bit-precise integers. Add macro for maximum bit width.^{[22] [23]}
• Add ckd_add, ckd_sub, ckd_mul macros for checked integer operations.^[24]
• Variably-modified types (but not VLAs which are automatic variables allocated on the stack) become a mandatory feature.^[25]
• Better support for using [[Const_(computer_programming)|const]] with arrays.^[26]
• Standardization of the [[typeof]](...) operator.^[27]
• The meaning of the keyword was changed to cause type inference while also retaining its old meaning of a storage class specifier if used alongside a type. Unlike C++, C23 allows type inference only for object definitions (no inferring function return type or function parameter type).^[28]
• Compatibility rules for structure, union, and enumerated types were changed to allow a redeclaration of a compatible type with the same tag.^[29]
• Exact-width integer may now exceed (N2888).^[30]

Constants

• Add constant for nullptr_t type.^[31]
• Add wb and uwb integer literal suffixes for and types,^[32] such as yields an unsigned _BitInt(3), and yields a signed _BitInt(4) which has three value bits and one sign bit.
• Add 0b and 0B binary literal constant prefixes,^[33] such as (equating to 0xAA).
• Add ' digit separator to literal constants,^[34] such as (equating to 0xFEDCBA98), (equating to 299792458), (equating to 1.414213562).
• Add the ability to specify the underlying type of an [[enumerated type|enum]].^[35]
• Allow s with no fixed underlying type to store values that are not representable by .^[36]

Keywords

• Add and keywords.^[37]
• Add,,,, keywords. Previously defined keywords become alternative spellings:,,,, .^[38]
• Add keyword (see "types" group)
• Add and keywords (see "types" group)
• Add keyword (see "constants" group)
• Add keyword (see "other" group)
• Add,, keywords for (optional) decimal floating-point arithmetic (see "other" group)

Syntax

• Labels can appear before declarations and at the end of compound statements.^[39]
• Unnamed parameters in function definitions.^[40]
• Zero initialization with {} (including initialization of VLAs).^[41]
• Variadic functions no longer need a named argument before the ellipsis and the macro no longer needs a second argument nor does it evaluate any argument after the first one if present.^[42]
• Add C++11 style attribute syntax^[43] using double square brackets . In addition to C++11 attributes listed below, add new attributes:
  • <nowiki>[[unsequenced]]</nowiki>^[44] allows compiler optimizations for functions producing repeatable outputs only based on their parameters
  • <nowiki>[[reproducible]]</nowiki>, similar to <nowiki>[[unsequenced]]</nowiki>, but for functions whose call order also matters
• Add single-argument [[Assert.h#static assert|_Static_assert]] for compatibility with C++17.^[45]
• Functions with no arguments listed in the prototype void foo are understood as taking no arguments (see removal of K&R function declarations)

C++ compatibility

• Various syntax changes improve compatibility with C++, such as labels before declarations, unnamed function arguments, zero initialization with {}, variadic functions without named argument, C++11 style attributes, [[Assert.h#static assert|_Static_assert]] (see Syntax). For labels at the end of compound statements a corresponding change was made to C++23.^[46]
• Add C++-style attributes (see Syntax). Add attributes^[47],^[48],^[49],^[50],^[51] and attribute for compatibility with C++11, then deprecate,, header <stdnoreturn.h> features introduced in C11.^[52] Duplicate attributes are allowed for compatibility with C++23.^[53] All standard attributes can also be surrounded by double underscores (e.g. is equivalent to).
• Add u8 prefix for character literals to represent UTF-8 encoding for compatibility with C++17.^{[54] [55]}
• Add and preprocessing directives for compatibility with C++23.^[15] (see "preprocessor" group)

Other features

• Support for the ISO/IEC 60559:2020, the current version of the IEEE 754 standard for floating-point arithmetic, with extended binary floating-point arithmetic and (optional) decimal floating-point arithmetic.^{[56] [57]}
• The [[constexpr]] specifier for objects but not functions, unlike C++'s equivalent.^[58]
• Add type for storing UTF-8 encoded data and change the type of u8 character constants and string literals to . Also, the functions mbrtoc8 and c8rtomb to convert a narrow multibyte character to UTF-8 encoding and a single code point from UTF-8 to a narrow multibyte character representation respectively.^[59]
• Clarify that all strings and literals shall be UTF-16 encoded, and all strings and literals shall be UTF-32 encoded, unless otherwise explicitly specified.^[60]
• Allow storage class specifiers to appear in compound literal definition.^[61]

Obsolete features

Some old obsolete features are either removed or deprecated from the working draft of C23:

• Remove trigraphs.^[62]

• Remove K&R function definitions/declarations (with no information about the function arguments).^{[63] [64]}

• Remove representations for signed integers other than two's complement. Two's complement signed integer representation will be required.^[65]

• The macros in <float.h> are obsolescent features.^[66]

Compiler support

The following compilers implement an experimental compiler flag to support this standard:

• GCC 9,^[67]
• Clang 9.0,^[68]
• Pelles C 11.00^[69]

Available texts

Like other editions of the C standard, the official ISO text of the standard is not freely available.

The latest working draft pre-C23 that was made public was N3096,^[5] dated 2023-04-01. In the months that followed this draft, hundreds of changes^[70] were made before producing the working draft N3149 dated 2023-07-09 and the official draft standard N3219 dated 2024-02-22.^[71] Neither of these later drafts is public.^{[70] [71]}

On the same date that the draft standard N3219 was announced, a new working draft N3220^[72] was made public. While this document is officially described^[71] as a draft of the future version "C2Y" of the standard, the accompanying "Editor's Report" specifies that N3220 differs from the draft C23 standard N3219 only by a fix to one footnote in Annex K.^[71]

See also

• C++23, C++20, C++17, C++14, C++11, C++03, C++98, versions of the C++ programming language standard
• Compatibility of C and C++

Further reading

• N3096 (last freely-available working draft before C23); WG14; April 2023. (free download)
• N3149 (working draft of C23 standard); WG14; July 2023. (not available to public)
• N3219 (ISO/IEC 9899:2023 DIS Draft); WG14; February 2024. (ISO draft available but not free)
• ISO/IEC 9899:2024 (official C23 standard); ISO; 2024. (planning for release in 2024)
• N3220 (first working draft after C23; differs from draft standard N3219 only in one footnote^[73]); WG14; February 2024. (free download)

External links

• C Language WG14 (Working Group 14)

• WG14 Document Repository

• WG14 Meetings - agenda and minutes

• WG14 Charters: C2x Charter, C23 Charter, Interpreting the C23 Charter, C Standard Charter

Notes and References

1. Web site: History of C . cppreference.com . https://web.archive.org/web/20221019191546/https://en.cppreference.com/w/c/language/history . October 19, 2022 . 2022-06-27 . live.
2. Web site: WG14-N2086: C2x Charter . open-std.org . https://web.archive.org/web/20221222213708/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2086.htm . December 22, 2022 . 2016-09-20 . live.
3. Web site: ISO/IEC PRF 9899 . iso.org . http://web.archive.org/web/20240919185914/https://www.iso.org/standard/82075.html . September 19, 2024 . live.
4. Web site: WG14-N2437: Agenda for October 2019 . open-std.org . https://web.archive.org/web/20210305073426/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2437.htm . March 5, 2021 . 2019-10-21 . live.
5. Web site: WG14-N3096: Draft for ISO/IEC 9899:2024 . open-std.org . https://web.archive.org/web/20230402172459/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf . April 2, 2023 . April 1, 2023 . live.
6. Web site: WG14-N2897: memset_explicit . open-std.org . https://web.archive.org/web/20221025074215/https://open-std.org/jtc1/sc22/wg14/www/docs/n2897.htm . October 25, 2022 . 2021-12-27 . live.
7. Web site: WG14-N2349: Toward more efficient string copying and concatenation . open-std.org . https://web.archive.org/web/20220930092258/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2349.htm . September 30, 2022 . 2019-03-18 . live.
8. Web site: WG14-N2353: strdup and strndup . open-std.org . https://web.archive.org/web/20221224063709/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2353.htm . December 24, 2022 . 2019-03-18 . live.
9. Web site: WG14-N2974: Queryable pointer alignment . open-std.org . https://web.archive.org/web/20221013182240/https://www.open-std.org/jtc1/sc22/WG14/www/docs/n2974.pdf . October 13, 2022 . 2022-04-15 . live.
10. Web site: WG14-N3022: Modern Bit Utilities . open-std.org . https://web.archive.org/web/20221224194734/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3022.htm . December 24, 2022 . 2022-07-06 . live.
11. Web site: WG14-N2833: Add timegm as non-optional part of time.h . open-std.org . https://web.archive.org/web/20211201062452/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2833.htm . December 1, 2021 . 2021-10-07 . live.
12. See N3096 § B.11 for a useful overview. The functions were added in separate documents: N2488, its updated versions, and its refs.
13. Web site: WG14-N2630: formatted input/output of binary integer numbers . open-std.org . https://web.archive.org/web/20221214154315/https://open-std.org/JTC1/SC22/WG14/www/docs/n2630.pdf . December 14, 2022 . 2021-01-01 . live.
14. Web site: WG14-N3020: Qualifier-preserving standard library functions . open-std.org . https://web.archive.org/web/20221013190826/https://www.open-std.org/jtc1/sc22/WG14/www/docs/n3020.pdf . October 13, 2022 . 2022-06-13 . live.
15. Web site: WG14-N2645: Add support for preprocessing directives #elifdef and #elifndef . open-std.org . https://web.archive.org/web/20221128133337/https://open-std.org/JTC1/SC22/WG14/www/docs/n2645.pdf . November 28, 2022 . 2020-01-25 . live.
16. Web site: GCC 12 Adds Support For New #elifdef #elifndef Directives . phoronix . https://web.archive.org/web/20221227050002/https://www.phoronix.com/news/GCC-12-elifdef-elifndef . December 27, 2022 . May 12, 2021 . live.
17. Web site: WG14-N3017: #embed - a scannable, tooling-friendly binary resource inclusion mechanism . open-std.org . https://web.archive.org/web/20221224045304/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3017.htm . December 24, 2022 . 2022-06-27 . live.
18. Web site: WG14-N2686: #warning . open-std.org . https://web.archive.org/web/20221128133337/https://open-std.org/JTC1/SC22/WG14/www/docs/n2686.pdf . November 28, 2022 . 2022-07-22 . live.
19. Web site: WG14-N2799: __has_include for C . open-std.org . https://web.archive.org/web/20221224103617/https://open-std.org/JTC1/SC22/WG14/www/docs/n2799.pdf . December 24, 2022 . 2021-08-30 . live.
20. Web site: WG14-N2553: Querying attribute support . open-std.org . https://web.archive.org/web/20221014221314/https://open-std.org/JTC1/SC22/WG14/www/docs/n2553.pdf . October 14, 2022 . 2020-08-04 . live.
21. Web site: WG14-N3033: Comma omission and comma deletion . open-std.org . https://web.archive.org/web/20221227031727/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3033.htm . December 27, 2022 . 2022-07-20 . live.
22. Web site: WG14-N2763: Adding a Fundamental Type for N-bit integers . open-std.org . https://web.archive.org/web/20221227055250/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2763.pdf . December 27, 2022 . 2021-06-21 . live.
23. Web site: WG14-N3035: _BitInt Fixes . open-std.org . https://web.archive.org/web/20221013182206/https://www.open-std.org/jtc1/sc22/WG14/www/docs/n3035.pdf . October 13, 2022 . 2022-07-21 . live.
24. Web site: WG14-N2867: Checked N-Bit Integers . open-std.org . https://web.archive.org/web/20221214154907/https://open-std.org/JTC1/SC22/WG14/www/docs/n2867.pdf . December 14, 2022 . 2021-11-28 . live.
25. Web site: WG14-N2778: Variably-Modified Types . open-std.org . https://web.archive.org/web/20221222053411/https://open-std.org/jtc1/sc22/wg14/www/docs/n2778.pdf . December 22, 2022 . 2021-07-11 . live.
26. Web site: WG14-N2607: Compatibility of Pointers to Arrays with Qualifiers . open-std.org . https://web.archive.org/web/20221013182946/https://www.open-std.org/jtc1/sc22/WG14/www/docs/n2607.pdf . October 13, 2022 . 2020-10-31 . live.
27. Web site: WG14-N2899: Not-so-magic - typeof for C . open-std.org . https://web.archive.org/web/20221224044528/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2899.htm . December 24, 2022 . 2022-01-21 . live.
28. Web site: WG14-N3007: Type inference for object definitions . open-std.org . https://web.archive.org/web/20221224105654/https://open-std.org/JTC1/SC22/WG14/www/docs/n3007.htm . December 24, 2022 . 2022-06-10 . live.
29. Web site: WG14-N3037: Improved Rules for Tag Compatibility (updates N3032) .
30. Web site: C23 is Finished: Here is What is on the Menu . The Pasture . en . 31 July 2022.
31. Web site: WR14-N3042: Introduce the nullptr constant . open-std.org . https://web.archive.org/web/20221224043228/https://open-std.org/JTC1/SC22/WG14/www/docs/n3042.htm . December 24, 2022 . 2022-07-22 . live.
32. Web site: WG14-N2775: Literal suffixes for bit-precise integers . open-std.org . https://web.archive.org/web/20221227014728/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2775.pdf . December 27, 2022 . 2021-07-13 . live.
33. Web site: WG14-N2549: Allow for binary integer constants . open-std.org . https://web.archive.org/web/20221222192818/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2549.pdf . December 22, 2022 . 2020-07-30 . live.
34. Web site: WG14-N2626: Digit separators . open-std.org . https://web.archive.org/web/20221219215425/https://open-std.org/JTC1/SC22/WG14/www/docs/n2626.pdf . December 19, 2022 . 2020-12-15 . live.
35. Web site: WG14-N3030: Enhancements to Enumerations . open-std.org . https://web.archive.org/web/20221126132709/https://open-std.org/JTC1/SC22/WG14/www/docs/n3030.htm . November 26, 2022 . 2022-07-19 . live.
36. Web site: WG14-N3029: Improved Normal Enumerations . open-std.org . https://web.archive.org/web/20230129180341/https://open-std.org/JTC1/SC22/WG14/www/docs/n3029.htm . January 29, 2023 . 2022-07-19 . live.
37. Web site: WG14-N2935: Make false and true first-class language features . open-std.org . https://web.archive.org/web/20221121123457/https://open-std.org/JTC1/SC22/WG14/www/docs/n2935.pdf . November 21, 2022 . 2022-02-15 . live.
38. Web site: WG14-N2934: Revise spelling of keywords . open-std.org . https://web.archive.org/web/20221224132455/https://open-std.org/JTC1/SC22/WG14/www/docs/n2934.pdf . December 24, 2022 . 2022-02-15 . live.
39. Web site: WG14-N2508: Free Positioning of Labels Inside Compound Statements . open-std.org . https://web.archive.org/web/20221227183107/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2508.pdf . December 27, 2022 . 2020-03-28 . live.
40. Web site: WG14-N2510: Allowing unnamed parameters in a function definition . open-std.org . https://web.archive.org/web/20221224075948/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2510.pdf . December 24, 2022 . 2020-04-09 . live.
41. Web site: WG14-N2900: Consistent, Warningless, and Intuitive Initialization with . open-std.org . https://web.archive.org/web/20221227181452/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2900.htm . December 27, 2022 . 2022-01-01 . live.
42. Web site: WG14-N2975: Relax requirements for variadic parameter lists . open-std.org . https://web.archive.org/web/20221128133337/https://open-std.org/JTC1/SC22/WG14/www/docs/n2975.pdf . November 28, 2022 . 2022-04-15 . live.
43. Web site: WG14-N2335: Attributes in C . open-std.org . https://web.archive.org/web/20221026060722/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2335.pdf . October 26, 2022 . 2019-03-09 . live.
44. Web site: Unsequenced functions . 2024-07-18 . open-std.org.
45. Web site: WG14-N2265: Harmonizing static_assert with C++ . open-std.org . https://web.archive.org/web/20230328064918/https://open-std.org/JTC1/SC22/WG14/www/docs/n2265.pdf . March 28, 2023 . 2018-07-06 . live.
46. Web site: Labels at the end of compound statements (C compatibility). 2022-01-13.
47. Web site: WG14-N2554: Minor attribute wording cleanups . open-std.org . https://web.archive.org/web/20221128133337/https://open-std.org/JTC1/SC22/WG14/www/docs/n2554.pdf . November 28, 2022 . 2020-08-04 . live.
48. Web site: WG14-N2334: The deprecated attribute . open-std.org . https://web.archive.org/web/20221019131835/https://open-std.org/JTC1/SC22/WG14/www/docs/n2334.pdf . October 19, 2022 . 2019-01-22 . live.
49. Web site: WG14-N2408: The fallthrough attribute . open-std.org . https://web.archive.org/web/20221225070709/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2408.pdf . December 25, 2022 . 2019-08-11 . live.
50. Web site: WG14-N2270: The maybe_unused attribute . open-std.org . https://web.archive.org/web/20221225070836/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2270.pdf . December 25, 2022 . 2018-07-06 . live.
51. Web site: WG14-N2267: The nodiscard attribute . open-std.org . https://web.archive.org/web/20221019131846/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2267.pdf . October 19, 2022 . 2018-07-06 . live.
52. Web site: WG14-N2764: The noreturn attribute . open-std.org . https://web.archive.org/web/20221225063437/https://open-std.org/JTC1/SC22/WG14/www/docs/n2764.pdf . December 25, 2022 . 2021-06-21 . live.
53. Web site: WG14-N2557: Allow Duplicate Attributes . open-std.org . https://web.archive.org/web/20221128133337/https://open-std.org/JTC1/SC22/WG14/www/docs/n2557.pdf . November 28, 2022 . 2020-09-01 . live.
54. Web site: WG14-N2418: Adding the u8 character prefix . open-std.org . https://web.archive.org/web/20230113210023/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2418.pdf . January 13, 2023 . 2019-09-02 . live.
55. https://stackoverflow.com/questions/31970111/what-is-the-point-of-the-utf-8-character-literals-proposed-for-c17#31970297 What is the point of the UTF-8 character literals proposed for C++17?; Stack Overflow.
56. Web site: WG14-N2341: ISO/IEC TS 18661-2 - Floating-point extensions for C - Part 2: Decimal floating-point arithmetic . open-std.org . https://web.archive.org/web/20221121122559/https://open-std.org/JTC1/SC22/WG14/www/docs/n2341.pdf . November 21, 2022 . February 26, 2019 . live.
57. Web site: WG14-N2601: Annex X - IEC 60559 interchange and extended types . open-std.org . https://web.archive.org/web/20221014221322/https://open-std.org/JTC1/SC22/WG14/www/docs/n2601.pdf . October 14, 2022 . October 15, 2020 . live.
58. Web site: WG14-N3018: The constexpr specifier for object definitions . open-std.org . https://web.archive.org/web/20221224074302/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3018.htm . December 24, 2022 . 2022-07-06 . live.
59. Web site: WG14-N2653: char8_t: A type for UTF-8 characters and strings (Revision 1) . open-std.org . https://web.archive.org/web/20230527110842/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2653.htm . May 27, 2023 . 2021-06-04 . live.
60. Web site: WG14-N2728: char16_t & char32_t string literals shall be UTF-16 & UTF-32 . open-std.org . https://web.archive.org/web/20230527110756/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2728.htm . May 27, 2023 . 2021-05-15 . live.
61. Web site: WG14-N3038: Introduce storage-class specifiers for compound literals . open-std.org . https://web.archive.org/web/20221126130057/https://open-std.org/JTC1/SC22/WG14/www/docs/n3038.htm . November 26, 2022 . 2022-07-21 . live.
62. Web site: WG14-N2940: Removing trigraphs??! . open-std.org . https://web.archive.org/web/20221026005747/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2940.pdf . October 26, 2022 . 2022-03-02 . live.
63. Web site: WG14-N2432: Remove support for function definitions with identifier lists proposal . open-std.org . https://web.archive.org/web/20221227012244/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2432.pdf . December 27, 2022 . September 25, 2019 . live.
64. Web site: WG14-N2841: No function declarators without prototypes . open-std.org . https://web.archive.org/web/20221112154740/https://www9.open-std.org/jtc1/sc22/wg14/www/docs/n2841.htm . November 12, 2022 . 2021-10-10 . live.
65. Web site: WG14-N2412: Two's complement sign representation . open-std.org . https://web.archive.org/web/20221227174224/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2412.pdf . December 27, 2022 . August 11, 2019 . live.
66. Web site: WG14-N2993: Make *_HAS_SUBNORM be obsolescent . open-std.org . https://web.archive.org/web/20221205194635/https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2993.htm . December 5, 2022 . 2022-06-06 . live.
67. Web site: GCC 9 Release Notes . live . https://web.archive.org/web/20221227032646/https://gcc.gnu.org/gcc-9/changes.html . December 27, 2022 . GNU Project.
68. Web site: May 14, 2019 . Clang 9.0 - add new language mode for C2x . live . https://web.archive.org/web/20221227032640/https://github.com/llvm/llvm-project/commit/d06f3917913d2558b771ccc48d838f8cd8993c01 . December 27, 2022 . LLVM Project Repository.
69. Web site: Pelles C - major changes between 10.00 and 11.00 . live . https://web.archive.org/web/20221227032644/http://www.smorgasbordet.com/pellesc/changes_1000_1100.htm . December 27, 2022 . smorgasbordet.com.
70. Web site: N3150 - Editor's Report, Post January-February 2023 Meeting . open-std.org . 2023-07-08.
71. Web site: N3221 - Editor's Report, Post January 2024 Meeting . open-std.org . 2024-02-15.
72. Web site: ISO/IEC 9899:2024 (en) — N3220 working draft . open-std.org . 2024-02-22.
73. Web site: N3221 - Editor's Report, Post January 2024 Meeting . open-std.org . 2024-02-15.