Difference between revisions of "cpp/23"
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See: {{stddoc|P1000R5|The current IS schedule for C++23}} (2023-05-10). | See: {{stddoc|P1000R5|The current IS schedule for C++23}} (2023-05-10). | ||
− | {{todo}} | + | {{todo|Check that all significant features are mentioned (using the Compiler Support tables below). Add more links and maybe regroup some lines.}} |
==New language features== | ==New language features== | ||
− | |||
* New [[cpp/feature test#Language features|language feature testing macros]] | * New [[cpp/feature test#Language features|language feature testing macros]] | ||
* {{ls|cpp/language/function#Explicit object parameter}}, {{lsd|cpp/language/member functions#Explicit object member functions}}, a.k.a. "deducing {{c/core|this}}" ({{stddoc|P0847R7}}) | * {{ls|cpp/language/function#Explicit object parameter}}, {{lsd|cpp/language/member functions#Explicit object member functions}}, a.k.a. "deducing {{c/core|this}}" ({{stddoc|P0847R7}}) | ||
* [[cpp/language/operators#Array subscript operator|Multidimensional subscript operator]] (e.g. {{c|1=v[1, 3, 7] = 42;}}) ({{stddoc|P2128R6}}) | * [[cpp/language/operators#Array subscript operator|Multidimensional subscript operator]] (e.g. {{c|1=v[1, 3, 7] = 42;}}) ({{stddoc|P2128R6}}) | ||
− | * {{c|static operator[]}} ({{stddoc|P2589R1}}), {{c|static operator()}} ({{stddoc|P1169R4}}) | + | * {{c|static operator[]}} ({{stddoc|P2589R1}}), {{c|static operator()}}, and static lambdas ({{stddoc|P1169R4}}) |
* {{c|auto(x)}} and {{c|auto{x}<!---->}}: [[cpp/language/explicit cast#Syntax|decay-copy]] in the language ({{stddoc|P0849R8}}) | * {{c|auto(x)}} and {{c|auto{x}<!---->}}: [[cpp/language/explicit cast#Syntax|decay-copy]] in the language ({{stddoc|P0849R8}}) | ||
* Assumptions via new attribute {{attr|assume|3=(''expression'')}} ({{stddoc|P1774R8}}) | * Assumptions via new attribute {{attr|assume|3=(''expression'')}} ({{stddoc|P1774R8}}) | ||
* Attributes on [[cpp/language/lambda#Syntax|lambda-expressions]] ({{stddoc|P2173R1}}) | * Attributes on [[cpp/language/lambda#Syntax|lambda-expressions]] ({{stddoc|P2173R1}}) | ||
− | * Optional [[cpp/types/floating-point|extended floating-point types]]: {{ | + | * Optional [[cpp/types/floating-point|extended floating-point types]]: {{c/core|std::float{16{{!}}32{{!}}64{{!}}128}_t}}, and {{c/core|std::bfloat16_t}} ({{stddoc|P1467R9}}) |
* New preprocessor directives: [[cpp/preprocessor/conditional|{{tt|#elifdef}}, {{tt|#elifndef}}]] ({{stddoc|P2334R1}}), and {{ltt|cpp/preprocessor/error|#warning}} ({{stddoc|P2437R1}}) | * New preprocessor directives: [[cpp/preprocessor/conditional|{{tt|#elifdef}}, {{tt|#elifndef}}]] ({{stddoc|P2334R1}}), and {{ltt|cpp/preprocessor/error|#warning}} ({{stddoc|P2437R1}}) | ||
− | * [[cpp/language/integer literal#The type of the literal|Literal suffix '{{tt|Z}}'/'{{tt|z}}']] for ({{c/core|signed}}) {{ | + | * [[cpp/language/integer literal#The type of the literal|Literal suffix '{{tt|Z}}'/'{{tt|z}}']] for ({{c/core|signed}}) {{c/core|std::size_t}} literals ({{stddoc|P0330R8}}), e.g. {{c|1=auto ouz = 0uz;}} |
* White-spaces trimming before line splicing. ({{stddoc|P2223R2}}) | * White-spaces trimming before line splicing. ({{stddoc|P2223R2}}) | ||
* Simpler implicit move ({{stddoc|P2266R3}}) | * Simpler implicit move ({{stddoc|P2266R3}}) | ||
* Extending the lifetime of temporaries in range-based for loop initializer ({{stddoc|P2718R0}}) | * Extending the lifetime of temporaries in range-based for loop initializer ({{stddoc|P2718R0}}) | ||
* CTAD from inherited constructors ({{stddoc|P2582R1}}) | * CTAD from inherited constructors ({{stddoc|P2582R1}}) | ||
− | * Labels at the end of compound statements ({{stddoc|P2324R2}}) | + | * Labels at the end of compound statements ({{stddoc|P2324R2}}), e.g.<br> |
− | * Alias declarations ({{c/core|using}}) in init-statements ({{stddoc|P2360R0}}) | + | : {{c multi| |
+ | void f(int& x)| | ||
+ | {| | ||
+ | if (x)| | ||
+ | goto END;| | ||
+ | x {{=}} 42;| | ||
+ | END:| | ||
+ | }<!---->}} | ||
+ | * Alias declarations ({{c/core|using}}) in init-statements ({{stddoc|P2360R0}}), e.g.<br> | ||
+ | : {{c multi | ||
+ | |for (using T {{=}} int; T e : v) | ||
+ | | /* ... */ | ||
+ | }} | ||
* Make {{ttb|()}} more optional for lambda expressions ({{stddoc|P1102R2}}) | * Make {{ttb|()}} more optional for lambda expressions ({{stddoc|P1102R2}}) | ||
* Narrowing contextual conversions to {{c/core|bool}} in {{c/core|static_assert}} and {{c/core|if constexpr}} ({{stddoc|P1401R5}}) | * Narrowing contextual conversions to {{c/core|bool}} in {{c/core|static_assert}} and {{c/core|if constexpr}} ({{stddoc|P1401R5}}) | ||
− | * Make declaration order layout mandated ({{stddoc|P1847R4}}) | + | * Make declaration order layout (of non-static class data members) mandated ({{stddoc|P1847R4}}) |
* Text encoding changes: | * Text encoding changes: | ||
** [[cpp/language/charset|Character sets and encodings]] ({{stddoc|P2314R4}}) | ** [[cpp/language/charset|Character sets and encodings]] ({{stddoc|P2314R4}}) | ||
Line 35: | Line 46: | ||
** [[cpp/language/escape|Delimited escape sequences]], e.g. {{c|"\o{7777}"}}, {{c|"\x{C0DE}"}}, {{c|"\u{CAFE}"}} ({{stddoc|P2290R3}}) | ** [[cpp/language/escape|Delimited escape sequences]], e.g. {{c|"\o{7777}"}}, {{c|"\x{C0DE}"}}, {{c|"\u{CAFE}"}} ({{stddoc|P2290R3}}) | ||
** [[cpp/language/translation_phases#Phase 1|Support for UTF-8 as a portable source file encoding]] ({{stddoc|P2295R6}}) | ** [[cpp/language/translation_phases#Phase 1|Support for UTF-8 as a portable source file encoding]] ({{stddoc|P2295R6}}) | ||
− | * {{ltt|cpp/language/if#Consteval if|if consteval / if not consteval}} ({{stddoc|P1938R3}}) | + | * {{ltt|cpp/language/if#Consteval if|if consteval}} / {{ltt|cpp/language/if#Consteval if|if not consteval}} ({{stddoc|P1938R3}}) |
* {{c/core|constexpr}} changes: | * {{c/core|constexpr}} changes: | ||
** Non-literal variables, labels, and {{c/core|goto}}s in {{c/core|constexpr}} functions ({{stddoc|P2242R3}}) | ** Non-literal variables, labels, and {{c/core|goto}}s in {{c/core|constexpr}} functions ({{stddoc|P2242R3}}) | ||
Line 43: | Line 54: | ||
==New library features== | ==New library features== | ||
− | + | * New [[cpp/feature test#Library features|library feature testing macros]] | |
===New modules=== | ===New modules=== | ||
− | * [[cpp/standard library#Importing modules|{{ | + | * [[cpp/standard library#Importing modules|{{tt|std}} and {{tt|std.compat}}]] ({{stddoc|P2465R3}}) |
===New headers=== | ===New headers=== | ||
Line 59: | Line 70: | ||
C compatibility headers: | C compatibility headers: | ||
− | * {{header|stdatomic.h}} | + | * {{header|stdatomic.h}} ({{stddoc|P0943R6}}) |
===Library features=== | ===Library features=== | ||
− | * | + | =====General Utilities===== |
− | * New [[cpp/algorithm/ranges#Constrained fold operations| | + | * {{c/core|std::expected}}: a new vocabulary type to return a function's result ({{header|expected}}) ({{stddoc|P0323R12}}, {{stddoc|P2549R1}}) |
− | * | + | * {{c/core|std::move_only_function}}: a move-only callable wrapper ({{stddoc|P0288R9}}) |
− | * | + | * {{c/core|std::bind_back}}: a call wrapper ({{stddoc|p2387r3}}) |
− | * {{c/core|std:: | + | * {{c/core|std::byteswap}}: reverses the bytes ({{stddoc|P1272R4}}) |
− | + | * {{c/core|std::forward_like}} ({{stddoc|P2445R1}}) | |
− | * {{ | + | * {{c/core|std::invoke_r}}: invokes a {{named req|Callable}} object ({{stddoc|p2136r3}}) |
− | * | + | * {{c/core|std::to_underlying}}: a utility function to get the underlying value of {{c/core|enum}} ({{stddoc|P1682R3}}) |
− | * {{c/core|std:: | + | * {{c/core|std::unreachable}}: a function to mark unreachable code ({{stddoc|p0627r6}}) |
− | * [[cpp/ | + | * Monadic operations ({{tt|transform}}, {{tt|or_else}}, and {{tt|and_then}}) for {{c/core|std::optional}} ({{stddoc|P0798R8}}) and {{c/core|std::expected}} ({{stddoc|P2505R5}}) |
− | * {{ | + | * {{c/core|std::tuple}} is compatible with other tuple-like objects ({{stddoc|p2165r4}}) |
− | * | + | * Adding default arguments for {{c/core|std::pair}}'s forwarding constructor ({{stddoc|p2718r0}}) |
− | * New | + | * {{c/core|std::basic_common_reference}} specialization for {{c/core|std::reference_wrapper}} yielding reference types ({{stddoc|p2655r3}}) |
− | * | + | |
− | * | + | =====Coroutine Library===== |
− | * | + | * {{c/core|std::generator}}: synchronous {{lt|cpp/language/coroutine}} generator for ranges ({{stddoc|P2502R2}}, {{stddoc|P2787R0}}) |
− | * | + | |
− | * {{c/core|std:: | + | =====Diagnostic===== |
− | + | * {{ls|cpp/utility#Stacktrace}} library ({{stddoc|p0881r7}}) | |
− | * {{c/core|std:: | + | |
− | * {{c/core|std:: | + | =====Algorithm, Iterators, and Ranges===== |
− | * | + | * New range adaptors: |
+ | ** {{c/core|views::adjacent}} and {{c/core|views::adjacent_transform}} ({{stddoc|P2321R2}}) | ||
+ | ** {{c/core|views::as_const}} ({{stddoc|P2278R4}}) | ||
+ | ** {{c/core|views::as_rvalue}} ({{stddoc|P2446R2}}) | ||
+ | ** {{c/core|views::cartesian_product}} ({{stddoc|p2374r4}}) | ||
+ | ** {{c/core|views::chunk_by}} ({{stddoc|P2443R1}}) | ||
+ | ** {{c/core|views::chunk}} ({{stddoc|P2442R1}}) | ||
+ | ** {{c/core|views::enumerate}} ({{stddoc|p2164r9}}) | ||
+ | ** {{c/core|views::join_with}} ({{stddoc|p2441r2}}) | ||
+ | ** {{c/core|views::repeat}} ({{stddoc|p2474r2}}) | ||
+ | ** {{c/core|views::slide}} ({{stddoc|P2442R1}}) | ||
+ | ** {{c/core|views::stride}} ({{stddoc|p1899r3}}) | ||
+ | ** {{c/core|views::zip}}, {{c/core|views::zip_transform}} ({{stddoc|P2321R2}}) | ||
+ | * {{c/core|ranges::range_adaptor_closure}}: a helper for program-defined range adaptor closures ({{stddoc|p2387r3}}) | ||
+ | * {{c/core|ranges::to}}: a range conversion function ({{stddoc|p1206r7}}) | ||
+ | * New constrained ranges algorithm: | ||
+ | ** {{c/core|ranges::starts_with}} and {{c/core|ranges::ends_with}} ({{stddoc|p1659r3}}) | ||
+ | ** {{c/core|ranges::contains}} and {{c/core|ranges::contains_subrange}} ({{stddoc|p2302r4}}) | ||
+ | ** {{c/core|ranges::find_last}}, {{c/core|ranges::find_last_if}}, and {{c/core|ranges::find_last_if_not}} ({{stddoc|p1223r5}}) | ||
+ | ** {{c/core|ranges::iota}}, {{c/core|ranges::shift_left}}, and {{c/core|ranges::shift_right}}: rangified versions of non-constrained algorithms ({{stddoc|p2440r1}}) | ||
+ | ** {{c/core|ranges::fold_left}} etc.: [[cpp/algorithm/ranges#Constrained fold operations|range fold algorithms]] ({{stddoc|p2322r6}}) | ||
+ | * Rectifying constant iterators, sentinels, and ranges, that is, {{c/core|ranges::cbegin}} and other similar utilities returning constant iterators should be fully guaranteed even for shallow-{{c/core|const}} views (such as {{c/core|std::span}}) ({{stddoc|p2278r4}}) | ||
+ | ** Making multi-param constructors of some views explicit ({{stddoc|p2711r1}}) | ||
+ | ** Ranges iterators as inputs to non-ranges algorithms ({{stddoc|p2408r5}}) | ||
+ | ** Relaxing range adaptors to allow for move only types ({{stddoc|p2494r2}}) | ||
+ | |||
+ | =====Containers===== | ||
+ | * {{c/core|std::mdspan}}: a non-owning multidimensional array reference ({{stddoc|P0009R18}}, {{stddoc|P2599R2}}, {{stddoc|P2604R0}}, {{stddoc|P2613R1}}, {{stddoc|P2763R1}}) | ||
+ | * Constructibility and assignability of containers from other compatible ranges ({{stddoc|p1206r7}}) | ||
+ | * {{c/core|std::flat_set}}, {{c/core|std::flat_multiset}} ({{stddoc|P1222R4}}), {{c/core|std::flat_map}}, {{c/core|std::flat_multimap}} ({{stddoc|P0429R9}}): flat sets and flat maps - container adaptors wrapping underlying sorted random-access containers | ||
+ | * Allowing iterator pair construction in {{c/core|std::stack}} and {{c/core|std::queue}} ({{stddoc|p1425r4}}) | ||
+ | * Heterogeneous erasure overloads for associative containers ({{stddoc|p2077r2}}) | ||
+ | * Non-deduction context for allocators in container deduction guides ({{stddoc|p1518r2}}) | ||
+ | * Requiring {{c/core|std::span}} and {{c/core|std::basic_string_view}} to be trivially copyable ({{stddoc|p2251r1}}) | ||
+ | |||
+ | =====Compile-time support===== | ||
+ | * {{c/core|constexpr}} support for: | ||
+ | ** {{c/core|std::bitset}} ({{stddoc|p2417r2}}) | ||
+ | ** {{c/core|std::unique_ptr}} ({{stddoc|p2273r3}}) | ||
+ | ** {{ltt|cpp/types/type_info/operator_cmp|2=std::type_info::operator==}} ({{stddoc|p1328r1}}) | ||
+ | ** Some {{header|cmath}} functions ({{stddoc|p0533r9}}) | ||
+ | ** Integral overloads of {{c/core|std::to_chars}} and {{c/core|std::from_chars}} ({{stddoc|p2291r3}}) | ||
+ | * [[cpp/meta|Metaprogramming]] utilities: | ||
+ | ** Adding move-only types support for comparison concepts ({{stddoc|p2404r3}}) | ||
+ | ** Type traits: | ||
+ | *** {{c/core|std::is_scoped_enum}} ({{stddoc|p1048r1}}) | ||
+ | *** {{c/core|std::is_implicit_lifetime}} ({{stddoc|p2674r1}}) | ||
+ | *** {{c/core|std::reference_constructs_from_temporary}}, and {{c/core|std::reference_converts_from_temporary}} ({{stddoc|p2255r2}}) | ||
+ | |||
+ | =====Memory Management===== | ||
+ | * {{c/core|std::out_ptr}} and {{c/core|std::inout_ptr}}: smart pointer adaptors for C interoperability ({{stddoc|p1132r7}}) | ||
+ | * {{c/core|std::allocate_at_least}} and {{c/core|std::allocator::allocate_at_least}} ({{stddoc|p0401r6}}) | ||
+ | * {{c/core|std::start_lifetime_as}}: an explicit lifetime management function for implicit-lifetime types ({{stddoc|p2590r2}}) | ||
+ | * Disallowing user specialization of {{c/core|std::allocator_traits}} ({{stddoc|p2652r2}}) | ||
+ | |||
+ | =====String and Text Processing===== | ||
+ | * New member functions and changes in string types: | ||
+ | ** {{c/core|std::basic_string::contains}} and {{c/core|std::basic_string_view::contains}} ({{stddoc|p1679r3}}) | ||
+ | ** Disabling construction from {{c|nullptr}} for {{c/core|std::basic_string}} and {{c/core|std::basic_string_view}} ({{stddoc|p2166r1}}) | ||
+ | ** Explicit range constructor for {{c/core|std::basic_string_view}} ({{stddoc|p1989r2}}) | ||
+ | ** {{c/core|std::basic_string::resize_and_overwrite}} ({{stddoc|p1072r10}}) | ||
+ | ** Rvalue reference overload of {{c/core|std::basic_string::substr}} for efficient slicing ({{stddoc|p2438r2}}) | ||
+ | * Formatting ranges, tuples, escaped presentation of characters and strings, {{c/core|std::thread::id}}, and {{lsd|cpp/utility#Stacktrace}}s. ({{stddoc|p2286r8}}) ({{stddoc|p2585r1}}) ({{stddoc|p2693r1}}) | ||
+ | |||
+ | =====I/O and print===== | ||
+ | * Formatted output functions {{c/core|std::print}} and {{c/core|std::println}} provided in header {{header|print}} ({{stddoc|p2093r14}}) | ||
+ | * {{ltt|cpp/spanstream}} library ({{c/core|std::span}}-based string stream) provided in header {{header|spanstream}} ({{stddoc|p0448r4}}) | ||
+ | * Support exclusive mode in {{c/core|std::fstreams}} ({{stddoc|p2467r1}}) | ||
+ | * Support of printing {{c|volatile T*}}: {{c|std::basic_ostream::operator<<(const volatile void*)}} ({{stddoc|P1147R1}}) | ||
==Obsolete== | ==Obsolete== | ||
=====Removed===== | =====Removed===== | ||
− | |||
* Garbage collection support and reachability-based leak detection. ({{stddoc|P2186R2}}) | * Garbage collection support and reachability-based leak detection. ({{stddoc|P2186R2}}) | ||
− | * Mixed wide string literals {{lsd|cpp/language/string literal#Concatenation | + | * Mixed wide string literals {{lsd|cpp/language/string literal#Concatenation}} support, e.g., {{c|1=const auto* no = u"q" U"p"}} is ill-formed. ({{stddoc|P2201R1}}) |
* Non-encodable wide character literals and multicharacter wide character literals, e.g. {{c|1=wchar_t x = 'db'}} is ill-formed. ({{stddoc|P2362R3}}) | * Non-encodable wide character literals and multicharacter wide character literals, e.g. {{c|1=wchar_t x = 'db'}} is ill-formed. ({{stddoc|P2362R3}}) | ||
=====Deprecated===== | =====Deprecated===== | ||
− | + | * {{c/core|std::aligned_storage}} and {{c/core|std::aligned_union}} ({{stddoc|P1413R3}}) | |
− | * {{ | + | * {{c/core|std::numeric_limits::has_denorm}} ({{stddoc|P2614R2}}) |
− | * {{ | + | |
− | =====Reverted | + | =====Reverted deprecations===== |
− | * The {{c | + | * The {{c|operator,}} (comma operator) in subscript expressions (but the semantics has been changed to support overloadable multidimensional subscript {{c|operator[]}}). |
− | * Some C headers ( | + | * Some C headers (the corresponding {{tt|<*.h>}} headers for compatibility with C) ({{stddoc|P2340R1}}) |
==Defect reports== | ==Defect reports== | ||
Line 105: | Line 182: | ||
==Compiler support== | ==Compiler support== | ||
− | Main Article: [[cpp/ | + | Main Article: [[cpp/compiler support#C++23 features|C++23 compiler support]] |
{{cpp/compiler support/23}} | {{cpp/compiler support/23}} | ||
{{cpp/compiler support/note}} | {{cpp/compiler support/note}} | ||
− | |||
===External links=== | ===External links=== | ||
+ | {{elink begin}} | ||
+ | {{elink|{{enwiki|C++23}} - Wikipedia}} | ||
+ | {{elink end}} | ||
+ | <!-- | ||
* [https://github.com/makelinux/examples/blob/HEAD/cpp/23.cpp Working C++23 examples] | * [https://github.com/makelinux/examples/blob/HEAD/cpp/23.cpp Working C++23 examples] | ||
--> | --> | ||
{{langlinks|es|ko|ru|zh}} | {{langlinks|es|ko|ru|zh}} |
Latest revision as of 05:59, 23 September 2024
The next generation of the C++ standard.
See: The current IS schedule for C++23 (2023-05-10).
This section is incomplete Reason: Check that all significant features are mentioned (using the Compiler Support tables below). Add more links and maybe regroup some lines. |
Contents |
[edit] New language features
- New language feature testing macros
- Explicit object parameter, explicit object member functions, a.k.a. "deducing this" (P0847R7)
- Multidimensional subscript operator (e.g. v[1, 3, 7] = 42;) (P2128R6)
- static operator[] (P2589R1), static operator(), and static lambdas (P1169R4)
- auto(x) and auto{x}: decay-copy in the language (P0849R8)
- Assumptions via new attribute
[[assume(expression)]]
(P1774R8) - Attributes on lambda-expressions (P2173R1)
- Optional extended floating-point types: std::float{16|32|64|128}_t, and std::bfloat16_t (P1467R9)
- New preprocessor directives:
#elifdef
,#elifndef
(P2334R1), and #warning (P2437R1) - Literal suffix '
Z
'/'z
' for (signed) std::size_t literals (P0330R8), e.g. auto ouz = 0uz; - White-spaces trimming before line splicing. (P2223R2)
- Simpler implicit move (P2266R3)
- Extending the lifetime of temporaries in range-based for loop initializer (P2718R0)
- CTAD from inherited constructors (P2582R1)
- Labels at the end of compound statements (P2324R2), e.g.
- void f(int& x)
{
if (x)
goto END;
x = 42;
END:
}
- Alias declarations (using) in init-statements (P2360R0), e.g.
- for (using T = int; T e : v)
/* ... */
- Make
()
more optional for lambda expressions (P1102R2) - Narrowing contextual conversions to bool in static_assert and if constexpr (P1401R5)
- Make declaration order layout (of non-static class data members) mandated (P1847R4)
- Text encoding changes:
- Character sets and encodings (P2314R4)
- Consistent character literal encoding (P2316R2)
- Named universal character escapes, e.g. "\N{CAT FACE}" for "🐱" (P2071R2)
- Delimited escape sequences, e.g. "\o{7777}", "\x{C0DE}", "\u{CAFE}" (P2290R3)
- Support for UTF-8 as a portable source file encoding (P2295R6)
- if consteval / if not consteval (P1938R3)
- constexpr changes:
- Non-literal variables, labels, and gotos in constexpr functions (P2242R3)
- Permitting static and thread_local variables in constant expressions in constexpr functions (P2647R1)
- constexpr function does not need its return type and parameter types to be literal type (P2448R2)
- constexpr function for which no invocation satisfies the requirements of a core constant expression (P2448R2)
[edit] New library features
[edit] New modules
[edit] New headers
C compatibility headers:
[edit] Library features
[edit] General Utilities
- std::expected: a new vocabulary type to return a function's result (<expected>) (P0323R12, P2549R1)
- std::move_only_function: a move-only callable wrapper (P0288R9)
- std::bind_back: a call wrapper (P2387R3)
- std::byteswap: reverses the bytes (P1272R4)
- std::forward_like (P2445R1)
- std::invoke_r: invokes a Callable object (P2136R3)
- std::to_underlying: a utility function to get the underlying value of enum (P1682R3)
- std::unreachable: a function to mark unreachable code (P0627R6)
- Monadic operations (
transform
,or_else
, andand_then
) for std::optional (P0798R8) and std::expected (P2505R5) - std::tuple is compatible with other tuple-like objects (P2165R4)
- Adding default arguments for std::pair's forwarding constructor (P2718R0)
- std::basic_common_reference specialization for std::reference_wrapper yielding reference types (P2655R3)
[edit] Coroutine Library
- std::generator: synchronous coroutine generator for ranges (P2502R2, P2787R0)
[edit] Diagnostic
- Stacktrace library (P0881R7)
[edit] Algorithm, Iterators, and Ranges
- New range adaptors:
- views::adjacent and views::adjacent_transform (P2321R2)
- views::as_const (P2278R4)
- views::as_rvalue (P2446R2)
- views::cartesian_product (P2374R4)
- views::chunk_by (P2443R1)
- views::chunk (P2442R1)
- views::enumerate (P2164R9)
- views::join_with (P2441R2)
- views::repeat (P2474R2)
- views::slide (P2442R1)
- views::stride (P1899R3)
- views::zip, views::zip_transform (P2321R2)
- ranges::range_adaptor_closure: a helper for program-defined range adaptor closures (P2387R3)
- ranges::to: a range conversion function (P1206R7)
- New constrained ranges algorithm:
- ranges::starts_with and ranges::ends_with (P1659R3)
- ranges::contains and ranges::contains_subrange (P2302R4)
- ranges::find_last, ranges::find_last_if, and ranges::find_last_if_not (P1223R5)
- ranges::iota, ranges::shift_left, and ranges::shift_right: rangified versions of non-constrained algorithms (P2440R1)
- ranges::fold_left etc.: range fold algorithms (P2322R6)
- Rectifying constant iterators, sentinels, and ranges, that is, ranges::cbegin and other similar utilities returning constant iterators should be fully guaranteed even for shallow-const views (such as std::span) (P2278R4)
[edit] Containers
- std::mdspan: a non-owning multidimensional array reference (P0009R18, P2599R2, P2604R0, P2613R1, P2763R1)
- Constructibility and assignability of containers from other compatible ranges (P1206R7)
- std::flat_set, std::flat_multiset (P1222R4), std::flat_map, std::flat_multimap (P0429R9): flat sets and flat maps - container adaptors wrapping underlying sorted random-access containers
- Allowing iterator pair construction in std::stack and std::queue (P1425R4)
- Heterogeneous erasure overloads for associative containers (P2077R2)
- Non-deduction context for allocators in container deduction guides (P1518R2)
- Requiring std::span and std::basic_string_view to be trivially copyable (P2251R1)
[edit] Compile-time support
- constexpr support for:
- std::bitset (P2417R2)
- std::unique_ptr (P2273R3)
- std::type_info::operator== (P1328R1)
- Some <cmath> functions (P0533R9)
- Integral overloads of std::to_chars and std::from_chars (P2291R3)
- Metaprogramming utilities:
- Adding move-only types support for comparison concepts (P2404R3)
- Type traits:
[edit] Memory Management
- std::out_ptr and std::inout_ptr: smart pointer adaptors for C interoperability (P1132R7)
- std::allocate_at_least and std::allocator::allocate_at_least (P0401R6)
- std::start_lifetime_as: an explicit lifetime management function for implicit-lifetime types (P2590R2)
- Disallowing user specialization of std::allocator_traits (P2652R2)
[edit] String and Text Processing
- New member functions and changes in string types:
- std::basic_string::contains and std::basic_string_view::contains (P1679R3)
- Disabling construction from nullptr for std::basic_string and std::basic_string_view (P2166R1)
- Explicit range constructor for std::basic_string_view (P1989R2)
- std::basic_string::resize_and_overwrite (P1072R10)
- Rvalue reference overload of std::basic_string::substr for efficient slicing (P2438R2)
- Formatting ranges, tuples, escaped presentation of characters and strings, std::thread::id, and stacktraces. (P2286R8) (P2585R1) (P2693R1)
[edit] I/O and print
- Formatted output functions std::print and std::println provided in header <print> (P2093R14)
- spanstream library (std::span-based string stream) provided in header <spanstream> (P0448R4)
- Support exclusive mode in std::fstreams (P2467R1)
- Support of printing volatile T*: std::basic_ostream::operator<<(const volatile void*) (P1147R1)
[edit] Obsolete
[edit] Removed
- Garbage collection support and reachability-based leak detection. (P2186R2)
- Mixed wide string literals concatenation support, e.g., const auto* no = u"q" U"p" is ill-formed. (P2201R1)
- Non-encodable wide character literals and multicharacter wide character literals, e.g. wchar_t x = 'db' is ill-formed. (P2362R3)
[edit] Deprecated
[edit] Reverted deprecations
- The operator, (comma operator) in subscript expressions (but the semantics has been changed to support overloadable multidimensional subscript operator[]).
- Some C headers (the corresponding
<*.h>
headers for compatibility with C) (P2340R1)
[edit] Defect reports
[edit] Compiler support
Main Article: C++23 compiler support
[edit] C++23 core language features
C++23 feature |
Paper(s) |
GCC |
Clang |
MSVC |
Apple Clang |
EDG eccp |
Intel C++ |
IBM XL C++ |
IBM Open XL C++ for AIX |
IBM Open XL C++ for z/OS |
Sun/Oracle C++ |
Embarcadero C++ Builder |
Cray |
Nvidia HPC C++ (ex PGI)* |
Nvidia nvcc |
|
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Literal suffix for (signed) size_t | P0330R8 | 11 | 13 |
13.1.6* |
6.5 | 2022.2 | ||||||||||
Make () more optional for lambdas
|
P1102R2 | 11 | 13 |
13.1.6* |
6.3 | 2022.2 | ||||||||||
if consteval | P1938R3 | 12 | 14 |
14.0.0* |
6.3 | 2022.2 | ||||||||||
Removing Garbage Collection Support | P2186R2 | 12 | N/A | 19.30* | N/A | |||||||||||
Narrowing contextual conversions in static_assert and constexpr if | P1401R5 | 9 | 13 (partial)* 14 |
14.0.0* |
2022.2 | |||||||||||
Trimming whitespaces before line splicing | P2223R2 | Yes | Yes | Yes | 2022.2 | |||||||||||
Make declaration order layout mandated | P1847R4 | Yes | Yes | Yes | Yes | 2022.2 | ||||||||||
Removing mixed wide string literal concatenation | P2201R1 | Yes | Yes | Yes | Yes | Yes | Yes | |||||||||
Explicit object member functions (deducing this) | P0847R7 | 14 | 18 19* |
19.32* (partial)* |
6.3 | |||||||||||
auto(x) and auto{x}
|
P0849R8 | 12 | 15 |
14.0.3* |
6.4 | 2022.2 | ||||||||||
#elifdef and #elifndef
|
P2334R1 | 12 | 13 | 19.40* |
13.1.6* |
6.5 | 2022.2 | |||||||||
Non-literal variables (and labels and gotos) in constexpr functions | P2242R3 | 12 | 15 |
14.0.3* |
6.3 | 2022.2 | ||||||||||
Consistent character literal encoding | P2316R2 | Yes | Yes | 19.30* | Yes | Yes | 2022.2 | |||||||||
Character sets and encodings | P2314R4 | 10 | Yes | Yes | 2022.2 | |||||||||||
Extend init-statement (of for loop) to allow alias-declaration
|
P2360R0 | 12 | 14 |
14.0.0* |
2022.2 | |||||||||||
Multidimensional subscript operator | P2128R6 | 12 | 15 |
14.0.3* |
2022.2 | |||||||||||
Attributes on lambdas | P2173R1 | 9 | 13 |
13.1.6* |
6.6 | 2022.2 | ||||||||||
#warning
|
P2437R1 | Yes* | Yes |
15.0.0* |
6.5 | 2023.2 | ||||||||||
Remove non-encodable wide character literals and multicharacter wide character literals | P2362R3 | 13 | 14 |
15.0.0* |
2023.2 | |||||||||||
Labels at the end of compound statements | P2324R2 | 13 | 16 | 6.5 | 2023.2 | |||||||||||
Delimited escape sequences | P2290R3 | 13 | 15 |
15.0.0* |
2023.2 | |||||||||||
Named universal character escapes | P2071R2 | 13 | 15 |
15.0.0* |
6.7 | 2023.2 | ||||||||||
Relaxing some constexpr restrictions | P2448R2 | 13 | 17 (partial) 19 |
2024.0 (partial) | ||||||||||||
Simpler implicit move | P2266R3 | 13 | 13 | 2022.2 | ||||||||||||
static operator() | P1169R4 | 13 | 16 | 2023.2 | ||||||||||||
Requirements for optional extended floating-point types | P1467R9 | 13 | N/A | 6.4 | ||||||||||||
Class template argument deduction from inherited constructors | P2582R1 | 14 | ||||||||||||||
Attribute [[assume]]
|
P1774R8 | 13 | 19 | |||||||||||||
Support for UTF-8 as a portable source file encoding | P2295R6 | 13* | 15* | 19.0 (Update 2)** |
15.0.0* |
2023.2 | ||||||||||
static operator[] | P2589R1 | 13 | 16 | 6.7 | 2023.2 | |||||||||||
Permitting static constexpr variables in constexpr functions | P2647R1 | 13 | 16 | 2023.2 | ||||||||||||
Extending the lifetime of temporaries in range-based for loop initializer | P2718R0 | 15 | 19 |
| ||||||||||||
DR11: Change scope of lambda trailing-return-type | P2036R3 P2579R0 |
17 | 2023.2 | |||||||||||||
DR20: Meaningful exports | P2615R1 | 15 | 17 (partial) | |||||||||||||
DR20: consteval needs to propagate up | P2564R0 | 14 | 17 | 2024.0 | ||||||||||||
DR98: C++ Identifier Syntax using Unicode Standard Annex 31 | P1949R7 | 12 | 14 |
14.0.0* |
6.4 | 2022.2 | ||||||||||
DR11: Allow duplicate attributes | P2156R1 | 11 | 13 |
13.1.6* |
6.5 | |||||||||||
DR20: Adjusting the value of feature-test macro __cpp_concepts
|
P2493R0 | 12 | 19.32* | 6.4 | ||||||||||||
DR98: Relax requirements on wchar_t to match existing practices | P2460R2 | Yes | Yes |
15.0.0* |
2023.2 | |||||||||||
DR11: Using unknown pointers and references in constant expressions | P2280R4 | 14 | ||||||||||||||
DR20: The Equality Operator You Are Looking For | P2468R2 | 13 | 16 | 2023.2 | ||||||||||||
DR20: char8_t Compatibility and Portability Fix | P2513R4 | 13 | 16 | 19.34* | 2023.2 | |||||||||||
DR98/11: Clarify reporting of diagnostic directives and allow static_assert of non-value-dependent expressions in a template context | CWG2518 | 13 | 17 | 16.0* (partial)* 19.40* |
||||||||||||
C++23 feature |
Paper(s) |
GCC |
Clang |
MSVC |
Apple Clang |
EDG eccp |
Intel C++ |
IBM XL C++ |
IBM Open XL C++ for AIX |
IBM Open XL C++ for z/OS |
Sun/Oracle C++ |
Embarcadero C++ Builder |
Cray |
Nvidia HPC C++ (ex PGI)* |
Nvidia nvcc |
[edit] C++23 library features
C++23 feature |
Paper(s) |
GCC libstdc++ |
Clang libc++ |
MSVC STL |
Apple Clang* |
IBM Open XL C/C++ for AIX* |
Sun/Oracle C++* |
Embarcadero C++ Builder* |
|
---|---|---|---|---|---|---|---|---|---|
Stacktrace library | P0881R7 P2301R1 |
12 (partial)* 14* |
19.34* | ||||||
<stdatomic.h> | P0943R6 | 12 | 15 | 19.31* |
14.0.3* |
||||
std::is_scoped_enum | P1048R1 | 11 | 12 | 19.30* |
13.0.0* |
||||
std::basic_string::contains(), std::basic_string_view::contains() | P1679R3 | 11 | 12 | 19.30* |
13.0.0* |
||||
std::to_underlying | P1682R3 | 11 | 13 | 19.30* |
13.1.6* |
||||
Relaxing requirements for time_point<>::clock | P2212R2 | N/A | N/A | N/A | N/A | ||||
Providing size feedback in the Allocator interface | P0401R6 | 15 | 19.30* |
14.0.3* |
|||||
<spanstream>: string-stream with std::span-based buffer | P0448R4 | 12 | 19.31* | ||||||
std::out_ptr(), std::inout_ptr() | P1132R8 | 14 | 19 | 19.30* | |||||
constexpr type_info::operator==()
|
P1328R1 | 12 | 17 | 19.33** 19.34* |
15.0.0* |
||||
Iterator pair constructors for std::stack and std::queue | P1425R4 | 12 | 14 | 19.31* |
14.0.3* |
||||
Non-deduction context for allocators in container deduction guides | P1518R2 | 12* | 13* | 19.31** |
13.1.6** |
||||
ranges::starts_with() and ranges::ends_with() | P1659R3 | 17 (partial)* 18 |
19.31* | ||||||
Prohibiting std::basic_string and std::basic_string_view construction from nullptr | P2166R1 | 12 | 13 | 19.30* |
13.1.6* |
||||
std::invoke_r() | P2136R3 | 12 | 17 | 19.31* |
15.0.0* |
||||
Range constructor for std::basic_string_view | P1989R2 | 11 | 14 | 19.30* |
14.0.3* |
||||
Default template arguments for std::pair's forwarding constructor | P1951R1 | 14 | 14 | 19.30* |
14.0.3* |
||||
Remove Garbage Collection and Reachability-Based Leak Detection (library support) | P2186R2 | 12 | 14 | 19.30* |
14.0.3* |
||||
zip: views::zip, views::zip_transform, views::adjacent, and views::adjacent_transform | P2321R2 | 13 | 15 (partial)* | 19.33*(partial)*** 19.37* |
14.0.3* |
||||
Heterogeneous erasure overloads for associative containers | P2077R3 | 19.32* | |||||||
std::byteswap() | P1272R4 | 12 | 14 | 19.31* |
14.0.3* |
||||
Printing volatile T* | P1147R1 | 11.3 | 14 | 19.31* |
14.0.3* |
||||
basic_string::resize_and_overwrite() | P1072R10 | 12 | 14 | 19.31* |
14.0.3* |
||||
Monadic operations for std::optional | P0798R8 | 12 | 14 | 19.32* |
14.0.3* |
||||
std::move_only_function | P0288R9 | 12 | 19.32* | ||||||
Add a conditional noexcept specification to std::exchange | P2401R0 | 12 | 14 | 19.25* |
14.0.3* |
||||
Require std::span & std::basic_string_view to be TriviallyCopyable | P2251R1 | Yes | Yes | Yes | Yes | ||||
Clarifying the status of the “C headers” | P2340R1 | Yes | Yes | Yes | Yes | ||||
<expected> | P0323R12 P2549R1 |
12 | 16 | 19.33* |
15.0.0* |
||||
constexpr for <cmath> and <cstdlib> | P0533R9 | 4.6 (partial)* | |||||||
std::unreachable() | P0627R6 | 12 | 15 | 19.32* |
14.0.3* |
||||
Deprecating std::aligned_storage and std::aligned_union | P1413R3 | 13 | 16 | 19.33* | |||||
std::reference_constructs_from_temporary & std::reference_converts_from_temporary | P2255R2 | 13 (partial)* 14 |
19 | ||||||
constexpr std::unique_ptr | P2273R3 | 12 | 16 | 19.33* |
15.0.0* |
||||
Constructing containers and strings from ranges with ranges::to(), tagged constructors, insert and assign member functions | P1206R7 | 14 (partial)* | 17 | 19.34* |
15.0.0* |
||||
Pipe support for user-defined range adaptors (ranges::range_adaptor_closure, std::bind_back) | P2387R3 | 13 (partial)* 14 |
19 | 19.34* | |||||
ranges::iota(), ranges::shift_left(), and ranges::shift_right() | P2440R1 | 13 (partial)* | 19.34* | ||||||
views::join_with | P2441R2 | 13 | 19.34* | ||||||
views::chunk and views::slide | P2442R1 | 13 | 19.33* | ||||||
views::chunk_by | P2443R1 | 13 | 18 | 19.33* | |||||
std::mdspan: a non-owning multidimensional array reference | P0009R18 P2599R2 P2604R0 P2613R1 P2763R1 |
17 (partial)* 18 |
19.39* |
15.0.0* |
|||||
<flat_map> | P0429R9 | 20 (partial)* | |||||||
<flat_set> | P1222R4 | ||||||||
ranges::find_last(), ranges::find_last_if(), and ranges::find_last_if_not() | P1223R5 | 13 | 19 | 19.36* | |||||
Freestanding Library: Easy <utility>, <ranges>, and <iterator> | P1642R11 | 13* | N/A | ||||||
views::stride | P1899R3 | 13 | 19.34* | ||||||
Compatibility between std::tuple and tuple-like objects | P2165R4 | 14 | 2.9 (partial)* | 19.36* (partial)* 19.37* |
partial* | ||||
Rectifying constant iterators, sentinels, and ranges. views::as_const | P2278R4 | 13 | 19.35* (partial)* 19.36* |
||||||
Formatting Ranges | P2286R8 | 16 | 19.37*(partial)* 19.39*(partial)* 19.41*(partial)* 19.42* |
15.0.0* |
|||||
Improve default container formatting | P2585R1 | 16 (partial)* 17 |
19.42* |
15.0.0* |
|||||
Formatted output library <print> | P2093R14 P2539R4 |
14 | 17 (partial)* 18 |
19.37* |
15.0.0** |
||||
Formatting std::thread::id and std::stacktrace | P2693R1 | 14 | 17 (partial)* | 19.38* |
15.0.0* |
||||
constexpr for integral overloads of std::to_chars() and std::from_chars().
|
P2291R3 | 13 | 16 | 19.34* |
15.0.0* |
||||
ranges::contains() and ranges::contains_subrange() | P2302R4 | 13 | 19 | 19.34* | |||||
Ranges fold algorithms | P2322R6 | 13 | 19.35* | ||||||
views::cartesian_product | P2374R4 P2540R1 |
13 | 19.37* | ||||||
Adding move-only types support for comparison concepts (equality_comparable , totally_ordered , three_way_comparable )
|
P2404R3 | 19.36* | |||||||
Ranges iterators as inputs to non-ranges algorithms | P2408R5 | 19.34* | |||||||
constexpr std::bitset | P2417R2 | 13 | 16 | 19.34* |
15.0.0* |
||||
basic_string::substr() &&
|
P2438R2 | 16 | 19.34* |
15.0.0* |
|||||
views::as_rvalue | P2446R2 | 13 | 16 | 19.34* |
15.0.0* |
||||
Standard Library Modules | P2465R3 | 17 (partial)* | 19.35* (partial)* 19.36* |
||||||
std::forward_like() | P2445R1 | 14 | 16 | 19.34* |
15.0.0* |
||||
Support exclusive mode for std::fstream | P2467R1 | 12 | 18 | 19.36* | |||||
views::repeat | P2474R2 | 13 | 17 | 19.36* |
15.0.0* |
||||
Relaxing range adaptors to allow for move-only types | P2494R2 | 14 | 17 | 19.34* |
15.0.0* |
||||
std::basic_string_view range constructor should be explicit | P2499R0 | 12.2 | 16 | 19.34* |
15.0.0* |
||||
std::generator: synchronous coroutine generator for ranges | P2502R2 P2787R0 |
14 | 19.43* | ||||||
Add a conditional noexcept specification to std::apply | P2517R1 | 10 | 18 | 19.34* | |||||
Explicit lifetime management (std::start_lifetime_as) | P2590R2 P2679R2 |
||||||||
Clarify handling of encodings in localized formatting of chrono types | P2419R2 | 15* | 19.34** | ||||||
std::move_iterator should not always be input_iterator
|
P2520R0 | 12.3* | 17* | 19.34** |
15.0.0* |
||||
Deduction guides update for explicit object parameter call operators | LWG3617 | 14 | 19.34* | ||||||
Deduction guides update for static operator() | P1169R4 | 13 | 16 | 19.39* |
15.0.0* |
||||
Standard names and library support for extended floating-point types | P1467R9 | 13 | 19.37** | ||||||
Monadic operations for std::expected | P2505R5 | 13 | 17 | 19.36* |
15.0.0* |
||||
views::enumerate | P2164R9 | 13 | 19.37* | ||||||
std::is_implicit_lifetime | P2674R1 | 20 | |||||||
std::common_reference_t of std::reference_wrapper should be a reference type | P2655R3 | 19.37* | |||||||
Disallowing user specialization of std::allocator_traits | P2652R2 | 19 | 19.37* | ||||||
Deprecating std::numeric_limits::has_denorm | P2614R2 | 18 | 19.37* | ||||||
Making Multi-Param Constructors Of views explicit | P2711R1 | 17 (partial)* | 19.36** |
15.0.0* |
|||||
DR20: Relaxing Ranges Just A Smidge | P2609R3 | 15 | 20 | 19.37* | |||||
DR20: Stashing Stashing Iterators For Proper Flattening | P2770R0 | 14 | 18 | 19.37* | |||||
DR17: std::visit() for classes derived from std::variant | P2162R2 | 11.3 | 13 | 19.20** 19.30* |
13.1.6* |
||||
DR20: Conditionally borrowed ranges | P2017R1 | 11 | 16 | 19.30* | |||||
DR20: Repairing input range adaptors and std::counted_iterator | P2259R1 | 12 | 19.30*(partial)* 19.31* |
||||||
DR20: views::join should join all views of ranges | P2328R1 | 11.2 | 15 | 19.30* |
14.0.3* |
||||
DR20: view does not require default_initializable
|
P2325R3 | 11.3 | 16 | 19.30* |
15.0.0* |
||||
DR20: Range adaptor objects bind arguments by value | P2281R1 | 11 | 14 | 19.29 (16.10)* (partial)* 19.31* |
14.0.3* |
||||
DR20: constexpr for std::optional and std::variant | P2231R1 | 11.3 (partial)* 12 |
13 (partial)* 19 |
19.31* |
13.1.6* (partial) |
||||
DR20: views::lazy_split and redesigned views::split | P2210R2 | 12 | 16 | 19.31* |
15.0.0* |
||||
DR20: Fix ranges::istream_view | P2432R1 | 12 | 16 | 19.31* |
15.0.0* |
||||
DR20: view with ownership
|
P2415R2 | 12 | 14 | 19.31* |
14.0.3* |
||||
DR20: Fixing locale handling in chrono formatters | P2372R3 | 13 | 19.31* | ||||||
DR20: Cleaning up integer-class types | P2393R1 | 19.32* | |||||||
DR20: std::format() improvements | P2216R3 | 13 | 14 (partial)* 15 |
19.32* |
14.0.3* |
||||
DR20: Add support for non-const-formattable types to std::format | P2418R2 | 13 | 15 | 19.32* |
14.0.3* |
||||
DR20: std::basic_format_string | P2508R1 | 13 | 15 | 19.35* |
14.0.3* |
||||
DR20: Poison Pills are Too Toxic | P2602R2 | 14 | 19 | 19.36* | |||||
DR20: std::format fill character allowances | P2572R1 | 14 | 17 | 19.37* | |||||
DR20: Improving std::format's width estimation | P2675R1 | 14 | 17 | 19.38* | |||||
DR20: std::barrier's phase completion guarantees | P2588R3 | 19.28 (16.8)** 19.36* |
|||||||
C++23 feature |
Paper(s) |
GCC libstdc++ |
Clang libc++ |
MSVC STL |
Apple Clang* |
IBM Open XL C/C++ for AIX* |
Sun/Oracle C++* |
Embarcadero C++ Builder* |
* - hover over a cell marked with the star * to see additional pop-up notes.
DRnn - the number nn after "DR" denotes target C++ revision the Defect Report is applied to, e.g., DR20 → C++20.
[edit] External links
C++23 - Wikipedia |