From Jason Turner

[support.limits]

C++20 → C++23 27.4 KB 211 lines
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Archived: C++20 | C++23
Markdown: C++20 | C++23
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  1. tmp/tmp6ubnj0dh/{from.md → to.md} +112 -84
tmp/tmp6ubnj0dh/{from.md → to.md} RENAMED
@@ -13,70 +13,94 @@ about the C++ standard library (e.g., version number and release date).
13
 
14
  Each of the macros defined in `<version>` is also defined after
15
  inclusion of any member of the set of library headers indicated in the
16
  corresponding comment in this synopsis.
17
 
18
- [*Note 1*: Future versions of this International Standard might replace
19
- the values of these macros with greater values. — *end note*]
20
 
21
  ``` cpp
22
  #define __cpp_lib_addressof_constexpr 201603L // also in <memory>
 
 
 
23
  #define __cpp_lib_allocator_traits_is_always_equal 201411L
24
  // also in <memory>, <scoped_allocator>, <string>, <deque>, <forward_list>, <list>, <vector>,
25
  // <map>, <set>, <unordered_map>, <unordered_set>
 
26
  #define __cpp_lib_any 201606L // also in <any>
27
  #define __cpp_lib_apply 201603L // also in <tuple>
28
  #define __cpp_lib_array_constexpr 201811L // also in <iterator>, <array>
29
  #define __cpp_lib_as_const 201510L // also in <utility>
 
 
30
  #define __cpp_lib_assume_aligned 201811L // also in <memory>
31
  #define __cpp_lib_atomic_flag_test 201907L // also in <atomic>
32
  #define __cpp_lib_atomic_float 201711L // also in <atomic>
33
  #define __cpp_lib_atomic_is_always_lock_free 201603L // also in <atomic>
34
  #define __cpp_lib_atomic_lock_free_type_aliases 201907L // also in <atomic>
35
  #define __cpp_lib_atomic_ref 201806L // also in <atomic>
36
  #define __cpp_lib_atomic_shared_ptr 201711L // also in <memory>
37
  #define __cpp_lib_atomic_value_initialization 201911L // also in <atomic>, <memory>
38
  #define __cpp_lib_atomic_wait 201907L // also in <atomic>
39
- #define __cpp_lib_barrier 201907L // also in <barrier>
 
40
  #define __cpp_lib_bind_front 201907L // also in <functional>
41
  #define __cpp_lib_bit_cast 201806L // also in <bit>
42
  #define __cpp_lib_bitops 201907L // also in <bit>
43
  #define __cpp_lib_bool_constant 201505L // also in <type_traits>
44
  #define __cpp_lib_bounded_array_traits 201902L // also in <type_traits>
45
  #define __cpp_lib_boyer_moore_searcher 201603L // also in <functional>
46
  #define __cpp_lib_byte 201603L // also in <cstddef>
 
47
  #define __cpp_lib_char8_t 201907L
48
  // also in <atomic>, <filesystem>, <istream>, <limits>, <locale>, <ostream>, <string>, <string_view>
49
  #define __cpp_lib_chrono 201907L // also in <chrono>
50
  #define __cpp_lib_chrono_udls 201304L // also in <chrono>
51
  #define __cpp_lib_clamp 201603L // also in <algorithm>
 
 
52
  #define __cpp_lib_complex_udls 201309L // also in <complex>
53
- #define __cpp_lib_concepts 202002L // also in <concepts>
54
- #define __cpp_lib_constexpr_algorithms 201806L // also in <algorithm>
 
 
 
55
  #define __cpp_lib_constexpr_complex 201711L // also in <complex>
56
  #define __cpp_lib_constexpr_dynamic_alloc 201907L // also in <memory>
57
  #define __cpp_lib_constexpr_functional 201907L // also in <functional>
58
  #define __cpp_lib_constexpr_iterator 201811L // also in <iterator>
59
- #define __cpp_lib_constexpr_memory 201811L // also in <memory>
60
  #define __cpp_lib_constexpr_numeric 201911L // also in <numeric>
61
  #define __cpp_lib_constexpr_string 201907L // also in <string>
62
  #define __cpp_lib_constexpr_string_view 201811L // also in <string_view>
63
  #define __cpp_lib_constexpr_tuple 201811L // also in <tuple>
 
64
  #define __cpp_lib_constexpr_utility 201811L // also in <utility>
65
  #define __cpp_lib_constexpr_vector 201907L // also in <vector>
 
 
 
66
  #define __cpp_lib_coroutine 201902L // also in <coroutine>
67
  #define __cpp_lib_destroying_delete 201806L // also in <new>
68
  #define __cpp_lib_enable_shared_from_this 201603L // also in <memory>
69
  #define __cpp_lib_endian 201907L // also in <bit>
70
  #define __cpp_lib_erase_if 202002L
71
  // also in <string>, <deque>, <forward_list>, <list>, <vector>, <map>, <set>, <unordered_map>,
72
  // <unordered_set>
73
  #define __cpp_lib_exchange_function 201304L // also in <utility>
74
  #define __cpp_lib_execution 201902L // also in <execution>
 
75
  #define __cpp_lib_filesystem 201703L // also in <filesystem>
76
- #define __cpp_lib_format 201907L // also in <format>
 
 
 
 
 
77
  #define __cpp_lib_gcd_lcm 201606L // also in <numeric>
 
78
  #define __cpp_lib_generic_associative_lookup 201304L // also in <map>, <set>
79
  #define __cpp_lib_generic_unordered_lookup 201811L
80
  // also in <unordered_map>, <unordered_set>
81
  #define __cpp_lib_hardware_interference_size 201703L // also in <new>
82
  #define __cpp_lib_has_unique_object_representations 201606L // also in <type_traits>
@@ -87,18 +111,22 @@ the values of these macros with greater values. — *end note*]
87
  #define __cpp_lib_integer_comparison_functions 202002L // also in <utility>
88
  #define __cpp_lib_integer_sequence 201304L // also in <utility>
89
  #define __cpp_lib_integral_constant_callable 201304L // also in <type_traits>
90
  #define __cpp_lib_interpolate 201902L // also in <cmath>, <numeric>
91
  #define __cpp_lib_invoke 201411L // also in <functional>
 
 
92
  #define __cpp_lib_is_aggregate 201703L // also in <type_traits>
93
  #define __cpp_lib_is_constant_evaluated 201811L // also in <type_traits>
94
  #define __cpp_lib_is_final 201402L // also in <type_traits>
 
95
  #define __cpp_lib_is_invocable 201703L // also in <type_traits>
96
  #define __cpp_lib_is_layout_compatible 201907L // also in <type_traits>
97
  #define __cpp_lib_is_nothrow_convertible 201806L // also in <type_traits>
98
  #define __cpp_lib_is_null_pointer 201309L // also in <type_traits>
99
  #define __cpp_lib_is_pointer_interconvertible 201907L // also in <type_traits>
 
100
  #define __cpp_lib_is_swappable 201603L // also in <type_traits>
101
  #define __cpp_lib_jthread 201911L // also in <stop_token>, <thread>
102
  #define __cpp_lib_latch 201907L // also in <latch>
103
  #define __cpp_lib_launder 201606L // also in <new>
104
  #define __cpp_lib_list_remove_return_type 201806L // also in <forward_list>, <list>
@@ -107,68 +135,102 @@ the values of these macros with greater values. — *end note*]
107
  #define __cpp_lib_make_reverse_iterator 201402L // also in <iterator>
108
  #define __cpp_lib_make_unique 201304L // also in <memory>
109
  #define __cpp_lib_map_try_emplace 201411L // also in <map>
110
  #define __cpp_lib_math_constants 201907L // also in <numbers>
111
  #define __cpp_lib_math_special_functions 201603L // also in <cmath>
 
112
  #define __cpp_lib_memory_resource 201603L // also in <memory_resource>
 
 
 
113
  #define __cpp_lib_node_extract 201606L
114
  // also in <map>, <set>, <unordered_map>, <unordered_set>
115
  #define __cpp_lib_nonmember_container_access 201411L
116
  // also in <array>, <deque>, <forward_list>, <iterator>, <list>, <map>, <regex>, <set>, <string>,
117
  // <unordered_map>, <unordered_set>, <vector>
118
  #define __cpp_lib_not_fn 201603L // also in <functional>
119
  #define __cpp_lib_null_iterators 201304L // also in <iterator>
120
- #define __cpp_lib_optional 201606L // also in <optional>
 
121
  #define __cpp_lib_parallel_algorithm 201603L // also in <algorithm>, <numeric>
122
- #define __cpp_lib_polymorphic_allocator 201902L // also in <memory>
 
123
  #define __cpp_lib_quoted_string_io 201304L // also in <iomanip>
124
- #define __cpp_lib_ranges 201911L
125
  // also in <algorithm>, <functional>, <iterator>, <memory>, <ranges>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
126
  #define __cpp_lib_raw_memory_algorithms 201606L // also in <memory>
 
127
  #define __cpp_lib_remove_cvref 201711L // also in <type_traits>
128
  #define __cpp_lib_result_of_sfinae 201210L // also in <functional>, <type_traits>
129
  #define __cpp_lib_robust_nonmodifying_seq_ops 201304L // also in <algorithm>
130
  #define __cpp_lib_sample 201603L // also in <algorithm>
131
  #define __cpp_lib_scoped_lock 201703L // also in <mutex>
132
  #define __cpp_lib_semaphore 201907L // also in <semaphore>
133
  #define __cpp_lib_shared_mutex 201505L // also in <shared_mutex>
134
  #define __cpp_lib_shared_ptr_arrays 201707L // also in <memory>
135
  #define __cpp_lib_shared_ptr_weak_type 201606L // also in <memory>
136
  #define __cpp_lib_shared_timed_mutex 201402L // also in <shared_mutex>
137
- #define __cpp_lib_shift 201806L // also in <algorithm>
138
  #define __cpp_lib_smart_ptr_for_overwrite 202002L // also in <memory>
139
  #define __cpp_lib_source_location 201907L // also in <source_location>
140
  #define __cpp_lib_span 202002L // also in <span>
 
141
  #define __cpp_lib_ssize 201902L // also in <iterator>
 
 
142
  #define __cpp_lib_starts_ends_with 201711L // also in <string>, <string_view>
 
 
 
143
  #define __cpp_lib_string_udls 201304L // also in <string>
144
  #define __cpp_lib_string_view 201803L // also in <string>, <string_view>
145
  #define __cpp_lib_syncbuf 201803L // also in <syncstream>
146
  #define __cpp_lib_three_way_comparison 201907L // also in <compare>
147
  #define __cpp_lib_to_address 201711L // also in <memory>
148
  #define __cpp_lib_to_array 201907L // also in <array>
149
  #define __cpp_lib_to_chars 201611L // also in <charconv>
 
150
  #define __cpp_lib_transformation_trait_aliases 201304L // also in <type_traits>
151
  #define __cpp_lib_transparent_operators 201510L // also in <memory>, <functional>
 
 
152
  #define __cpp_lib_tuple_element_t 201402L // also in <tuple>
153
  #define __cpp_lib_tuples_by_type 201304L // also in <utility>, <tuple>
154
  #define __cpp_lib_type_identity 201806L // also in <type_traits>
155
  #define __cpp_lib_type_trait_variable_templates 201510L // also in <type_traits>
156
  #define __cpp_lib_uncaught_exceptions 201411L // also in <exception>
157
  #define __cpp_lib_unordered_map_try_emplace 201411L // also in <unordered_map>
 
158
  #define __cpp_lib_unwrap_ref 201811L // also in <type_traits>
159
- #define __cpp_lib_variant 201606L // also in <variant>
160
  #define __cpp_lib_void_t 201411L // also in <type_traits>
161
  ```
162
 
163
  ### Header `<limits>` synopsis <a id="limits.syn">[[limits.syn]]</a>
164
 
165
  ``` cpp
 
166
  namespace std {
167
- // [fp.style], floating-point type properties
168
  enum float_round_style;
169
- enum float_denorm_style;
170
 
171
  // [numeric.limits], class template numeric_limits
172
  template<class T> class numeric_limits;
173
 
174
  template<class T> class numeric_limits<const T>;
@@ -198,13 +260,11 @@ namespace std {
198
  template<> class numeric_limits<double>;
199
  template<> class numeric_limits<long double>;
200
  }
201
  ```
202
 
203
- ### Floating-point type properties <a id="fp.style">[[fp.style]]</a>
204
-
205
- #### Type `float_round_style` <a id="round.style">[[round.style]]</a>
206
 
207
  ``` cpp
208
  namespace std {
209
  enum float_round_style {
210
  round_indeterminate = -1,
@@ -225,32 +285,14 @@ values:
225
  representable value
226
  - `round_toward_infinity` if the rounding style is toward infinity
227
  - `round_toward_neg_infinity` if the rounding style is toward negative
228
  infinity
229
 
230
- #### Type `float_denorm_style` <a id="denorm.style">[[denorm.style]]</a>
231
-
232
- ``` cpp
233
- namespace std {
234
- enum float_denorm_style {
235
- denorm_indeterminate = -1,
236
- denorm_absent = 0,
237
- denorm_present = 1
238
- };
239
- }
240
- ```
241
-
242
- The presence or absence of subnormal numbers (variable number of
243
- exponent bits) is characterized by the values:
244
-
245
- - `denorm_indeterminate` if it cannot be determined whether or not the
246
- type allows subnormal values
247
- - `denorm_absent` if the type does not allow subnormal values
248
- - `denorm_present` if the type does allow subnormal values
249
-
250
  ### Class template `numeric_limits` <a id="numeric.limits">[[numeric.limits]]</a>
251
 
 
 
252
  The `numeric_limits` class template provides a C++ program with
253
  information about various properties of the implementation’s
254
  representation of the arithmetic types.
255
 
256
  ``` cpp
@@ -278,12 +320,10 @@ namespace std {
278
  static constexpr int max_exponent10 = 0;
279
 
280
  static constexpr bool has_infinity = false;
281
  static constexpr bool has_quiet_NaN = false;
282
  static constexpr bool has_signaling_NaN = false;
283
- static constexpr float_denorm_style has_denorm = denorm_absent;
284
- static constexpr bool has_denorm_loss = false;
285
  static constexpr T infinity() noexcept { return T(); }
286
  static constexpr T quiet_NaN() noexcept { return T(); }
287
  static constexpr T signaling_NaN() noexcept { return T(); }
288
  static constexpr T denorm_min() noexcept { return T(); }
289
 
@@ -300,12 +340,16 @@ namespace std {
300
 
301
  For all members declared `static` `constexpr` in the `numeric_limits`
302
  template, specializations shall define these values in such a way that
303
  they are usable as constant expressions.
304
 
305
- The default `numeric_limits<T>` template shall have all members, but
306
- with 0 or `false` values.
 
 
 
 
307
 
308
  Specializations shall be provided for each arithmetic type, both
309
  floating-point and integer, including `bool`. The member
310
  `is_specialized` shall be `true` for all such specializations of
311
  `numeric_limits`.
@@ -497,96 +541,82 @@ Number”.[^17]
497
 
498
  Meaningful for all floating-point types.
499
 
500
  Shall be `true` for all specializations in which `is_iec559 != false`.
501
 
502
- ``` cpp
503
- static constexpr float_denorm_style has_denorm;
504
- ```
505
-
506
- `denorm_present` if the type allows subnormal values (variable number of
507
- exponent bits)[^18], `denorm_absent` if the type does not allow
508
- subnormal values, and `denorm_indeterminate` if it is indeterminate at
509
- compile time whether the type allows subnormal values.
510
-
511
- Meaningful for all floating-point types.
512
-
513
- ``` cpp
514
- static constexpr bool has_denorm_loss;
515
- ```
516
-
517
- `true` if loss of accuracy is detected as a denormalization loss, rather
518
- than as an inexact result.[^19]
519
-
520
  ``` cpp
521
  static constexpr T infinity() noexcept;
522
  ```
523
 
524
- Representation of positive infinity, if available.[^20]
525
 
526
  Meaningful for all specializations for which `has_infinity != false`.
527
  Required in specializations for which `is_iec559 != false`.
528
 
529
  ``` cpp
530
  static constexpr T quiet_NaN() noexcept;
531
  ```
532
 
533
- Representation of a quiet “Not a Number”, if available.[^21]
534
 
535
  Meaningful for all specializations for which `has_quiet_NaN != false`.
536
  Required in specializations for which `is_iec559 != false`.
537
 
538
  ``` cpp
539
  static constexpr T signaling_NaN() noexcept;
540
  ```
541
 
542
- Representation of a signaling “Not a Number”, if available.[^22]
543
 
544
  Meaningful for all specializations for which
545
  `has_signaling_NaN != false`. Required in specializations for which
546
  `is_iec559 != false`.
547
 
548
  ``` cpp
549
  static constexpr T denorm_min() noexcept;
550
  ```
551
 
552
- Minimum positive subnormal value.[^23]
 
 
553
 
554
  Meaningful for all floating-point types.
555
 
556
- In specializations for which `has_denorm == false`, returns the minimum
557
- positive normalized value.
558
-
559
  ``` cpp
560
  static constexpr bool is_iec559;
561
  ```
562
 
563
- `true` if and only if the type adheres to ISO/IEC/IEEE 60559.[^24]
 
 
 
 
564
 
565
  Meaningful for all floating-point types.
566
 
567
  ``` cpp
568
  static constexpr bool is_bounded;
569
  ```
570
 
571
- `true` if the set of values representable by the type is finite.[^25]
572
 
573
- [*Note 1*: All fundamental types [[basic.fundamental]] are bounded.
574
  This member would be `false` for arbitrary precision
575
  types. — *end note*]
576
 
577
  Meaningful for all specializations.
578
 
579
  ``` cpp
580
  static constexpr bool is_modulo;
581
  ```
582
 
583
- `true` if the type is modulo.[^26] A type is modulo if, for any
584
- operation involving `+`, `-`, or `*` on values of that type whose result
585
- would fall outside the range \[`min()`, `max()`\], the value returned
586
- differs from the true value by an integer multiple of
587
- `max() - min() + 1`.
 
588
 
589
  [*Example 1*: `is_modulo` is `false` for signed integer
590
  types [[basic.fundamental]] unless an implementation, as an extension to
591
  this document, defines signed integer overflow to
592
  wrap. — *end example*]
@@ -596,27 +626,27 @@ Meaningful for all specializations.
596
  ``` cpp
597
  static constexpr bool traps;
598
  ```
599
 
600
  `true` if, at the start of the program, there exists a value of the type
601
- that would cause an arithmetic operation using that value to trap.[^27]
602
 
603
  Meaningful for all specializations.
604
 
605
  ``` cpp
606
  static constexpr bool tinyness_before;
607
  ```
608
 
609
- `true` if tinyness is detected before rounding.[^28]
610
 
611
  Meaningful for all floating-point types.
612
 
613
  ``` cpp
614
  static constexpr float_round_style round_style;
615
  ```
616
 
617
- The rounding style for the type.[^29]
618
 
619
  Meaningful for all floating-point types. Specializations for integer
620
  types shall return `round_toward_zero`.
621
 
622
  #### `numeric_limits` specializations <a id="numeric.special">[[numeric.special]]</a>
@@ -656,12 +686,10 @@ namespace std {
656
  static constexpr int max_exponent10 = + 38;
657
 
658
  static constexpr bool has_infinity = true;
659
  static constexpr bool has_quiet_NaN = true;
660
  static constexpr bool has_signaling_NaN = true;
661
- static constexpr float_denorm_style has_denorm = denorm_absent;
662
- static constexpr bool has_denorm_loss = false;
663
 
664
  static constexpr float infinity() noexcept { return value; }
665
  static constexpr float quiet_NaN() noexcept { return value; }
666
  static constexpr float signaling_NaN() noexcept { return value; }
667
  static constexpr float denorm_min() noexcept { return min(); }
@@ -707,12 +735,10 @@ namespace std {
707
  static constexpr int max_exponent10 = 0;
708
 
709
  static constexpr bool has_infinity = false;
710
  static constexpr bool has_quiet_NaN = false;
711
  static constexpr bool has_signaling_NaN = false;
712
- static constexpr float_denorm_style has_denorm = denorm_absent;
713
- static constexpr bool has_denorm_loss = false;
714
  static constexpr bool infinity() noexcept { return 0; }
715
  static constexpr bool quiet_NaN() noexcept { return 0; }
716
  static constexpr bool signaling_NaN() noexcept { return 0; }
717
  static constexpr bool denorm_min() noexcept { return 0; }
718
 
@@ -728,10 +754,11 @@ namespace std {
728
  ```
729
 
730
  ### Header `<climits>` synopsis <a id="climits.syn">[[climits.syn]]</a>
731
 
732
  ``` cpp
 
733
  #define CHAR_BIT see below
734
  #define SCHAR_MIN see below
735
  #define SCHAR_MAX see below
736
  #define UCHAR_MAX see below
737
  #define CHAR_MIN see below
@@ -752,19 +779,20 @@ namespace std {
752
  ```
753
 
754
  The header `<climits>` defines all macros the same as the C standard
755
  library header `<limits.h>`.
756
 
757
- [*Note 1*: The types of the constants defined by macros in `<climits>`
758
- are not required to match the types to which the macros
759
- refer. — *end note*]
760
 
761
  See also: ISO C 5.2.4.2.1
762
 
763
  ### Header `<cfloat>` synopsis <a id="cfloat.syn">[[cfloat.syn]]</a>
764
 
765
  ``` cpp
 
766
  #define FLT_ROUNDS see below
767
  #define FLT_EVAL_METHOD see below
768
  #define FLT_HAS_SUBNORM see below
769
  #define DBL_HAS_SUBNORM see below
770
  #define LDBL_HAS_SUBNORM see below
 
13
 
14
  Each of the macros defined in `<version>` is also defined after
15
  inclusion of any member of the set of library headers indicated in the
16
  corresponding comment in this synopsis.
17
 
18
+ [*Note 1*: Future revisions of C++ might replace the values of these
19
+ macros with greater values. — *end note*]
20
 
21
  ``` cpp
22
  #define __cpp_lib_addressof_constexpr 201603L // also in <memory>
23
+ #define __cpp_lib_algorithm_iterator_requirements 202207L
24
+ // also in <algorithm>, <numeric>, <memory>
25
+ #define __cpp_lib_allocate_at_least 202302L // also in <memory>
26
  #define __cpp_lib_allocator_traits_is_always_equal 201411L
27
  // also in <memory>, <scoped_allocator>, <string>, <deque>, <forward_list>, <list>, <vector>,
28
  // <map>, <set>, <unordered_map>, <unordered_set>
29
+ #define __cpp_lib_adaptor_iterator_pair_constructor 202106L // also in <stack>, <queue>
30
  #define __cpp_lib_any 201606L // also in <any>
31
  #define __cpp_lib_apply 201603L // also in <tuple>
32
  #define __cpp_lib_array_constexpr 201811L // also in <iterator>, <array>
33
  #define __cpp_lib_as_const 201510L // also in <utility>
34
+ #define __cpp_lib_associative_heterogeneous_erasure 202110L
35
+ // also in <map>, <set>, <unordered_map>, <unordered_set>
36
  #define __cpp_lib_assume_aligned 201811L // also in <memory>
37
  #define __cpp_lib_atomic_flag_test 201907L // also in <atomic>
38
  #define __cpp_lib_atomic_float 201711L // also in <atomic>
39
  #define __cpp_lib_atomic_is_always_lock_free 201603L // also in <atomic>
40
  #define __cpp_lib_atomic_lock_free_type_aliases 201907L // also in <atomic>
41
  #define __cpp_lib_atomic_ref 201806L // also in <atomic>
42
  #define __cpp_lib_atomic_shared_ptr 201711L // also in <memory>
43
  #define __cpp_lib_atomic_value_initialization 201911L // also in <atomic>, <memory>
44
  #define __cpp_lib_atomic_wait 201907L // also in <atomic>
45
+ #define __cpp_lib_barrier 202302L // also in <barrier>
46
+ #define __cpp_lib_bind_back 202202L // also in <functional>
47
  #define __cpp_lib_bind_front 201907L // also in <functional>
48
  #define __cpp_lib_bit_cast 201806L // also in <bit>
49
  #define __cpp_lib_bitops 201907L // also in <bit>
50
  #define __cpp_lib_bool_constant 201505L // also in <type_traits>
51
  #define __cpp_lib_bounded_array_traits 201902L // also in <type_traits>
52
  #define __cpp_lib_boyer_moore_searcher 201603L // also in <functional>
53
  #define __cpp_lib_byte 201603L // also in <cstddef>
54
+ #define __cpp_lib_byteswap 202110L // also in <bit>
55
  #define __cpp_lib_char8_t 201907L
56
  // also in <atomic>, <filesystem>, <istream>, <limits>, <locale>, <ostream>, <string>, <string_view>
57
  #define __cpp_lib_chrono 201907L // also in <chrono>
58
  #define __cpp_lib_chrono_udls 201304L // also in <chrono>
59
  #define __cpp_lib_clamp 201603L // also in <algorithm>
60
+ #define __cpp_lib_common_reference 202302L // also in <type_traits>
61
+ #define __cpp_lib_common_reference_wrapper 202302L // also in <functional>
62
  #define __cpp_lib_complex_udls 201309L // also in <complex>
63
+ #define __cpp_lib_concepts 202207L // also in <concepts>, <compare>
64
+ #define __cpp_lib_constexpr_algorithms 201806L // also in <algorithm>, <utility>
65
+ #define __cpp_lib_constexpr_bitset 202207L // also in <bitset>
66
+ #define __cpp_lib_constexpr_charconv 202207L // also in <charconv>
67
+ #define __cpp_lib_constexpr_cmath 202202L // also in <cmath>, <cstdlib>
68
  #define __cpp_lib_constexpr_complex 201711L // also in <complex>
69
  #define __cpp_lib_constexpr_dynamic_alloc 201907L // also in <memory>
70
  #define __cpp_lib_constexpr_functional 201907L // also in <functional>
71
  #define __cpp_lib_constexpr_iterator 201811L // also in <iterator>
72
+ #define __cpp_lib_constexpr_memory 202202L // also in <memory>
73
  #define __cpp_lib_constexpr_numeric 201911L // also in <numeric>
74
  #define __cpp_lib_constexpr_string 201907L // also in <string>
75
  #define __cpp_lib_constexpr_string_view 201811L // also in <string_view>
76
  #define __cpp_lib_constexpr_tuple 201811L // also in <tuple>
77
+ #define __cpp_lib_constexpr_typeinfo 202106L // also in <typeinfo>
78
  #define __cpp_lib_constexpr_utility 201811L // also in <utility>
79
  #define __cpp_lib_constexpr_vector 201907L // also in <vector>
80
+ #define __cpp_lib_containers_ranges 202202L
81
+ // also in <vector>, <list>, <forward_list>, <map>, <set>, <unordered_map>, <unordered_set>,
82
+ // <deque>, <queue>, <stack>, <string>
83
  #define __cpp_lib_coroutine 201902L // also in <coroutine>
84
  #define __cpp_lib_destroying_delete 201806L // also in <new>
85
  #define __cpp_lib_enable_shared_from_this 201603L // also in <memory>
86
  #define __cpp_lib_endian 201907L // also in <bit>
87
  #define __cpp_lib_erase_if 202002L
88
  // also in <string>, <deque>, <forward_list>, <list>, <vector>, <map>, <set>, <unordered_map>,
89
  // <unordered_set>
90
  #define __cpp_lib_exchange_function 201304L // also in <utility>
91
  #define __cpp_lib_execution 201902L // also in <execution>
92
+ #define __cpp_lib_expected 202211L // also in <expected>
93
  #define __cpp_lib_filesystem 201703L // also in <filesystem>
94
+ #define __cpp_lib_flat_map 202207L // also in <flat_map>
95
+ #define __cpp_lib_flat_set 202207L // also in <flat_set>
96
+ #define __cpp_lib_format 202207L // also in <format>
97
+ #define __cpp_lib_format_ranges 202207L // also in <format>
98
+ #define __cpp_lib_formatters 202302L // also in <stacktrace>, <thread>
99
+ #define __cpp_lib_forward_like 202207L // also in <utility>
100
  #define __cpp_lib_gcd_lcm 201606L // also in <numeric>
101
+ #define __cpp_lib_generator 202207L // also in <generator>
102
  #define __cpp_lib_generic_associative_lookup 201304L // also in <map>, <set>
103
  #define __cpp_lib_generic_unordered_lookup 201811L
104
  // also in <unordered_map>, <unordered_set>
105
  #define __cpp_lib_hardware_interference_size 201703L // also in <new>
106
  #define __cpp_lib_has_unique_object_representations 201606L // also in <type_traits>
 
111
  #define __cpp_lib_integer_comparison_functions 202002L // also in <utility>
112
  #define __cpp_lib_integer_sequence 201304L // also in <utility>
113
  #define __cpp_lib_integral_constant_callable 201304L // also in <type_traits>
114
  #define __cpp_lib_interpolate 201902L // also in <cmath>, <numeric>
115
  #define __cpp_lib_invoke 201411L // also in <functional>
116
+ #define __cpp_lib_invoke_r 202106L // also in <functional>
117
+ #define __cpp_lib_ios_noreplace 202207L // also in <ios>
118
  #define __cpp_lib_is_aggregate 201703L // also in <type_traits>
119
  #define __cpp_lib_is_constant_evaluated 201811L // also in <type_traits>
120
  #define __cpp_lib_is_final 201402L // also in <type_traits>
121
+ #define __cpp_lib_is_implicit_lifetime 202302L // also in <type_traits>
122
  #define __cpp_lib_is_invocable 201703L // also in <type_traits>
123
  #define __cpp_lib_is_layout_compatible 201907L // also in <type_traits>
124
  #define __cpp_lib_is_nothrow_convertible 201806L // also in <type_traits>
125
  #define __cpp_lib_is_null_pointer 201309L // also in <type_traits>
126
  #define __cpp_lib_is_pointer_interconvertible 201907L // also in <type_traits>
127
+ #define __cpp_lib_is_scoped_enum 202011L // also in <type_traits>
128
  #define __cpp_lib_is_swappable 201603L // also in <type_traits>
129
  #define __cpp_lib_jthread 201911L // also in <stop_token>, <thread>
130
  #define __cpp_lib_latch 201907L // also in <latch>
131
  #define __cpp_lib_launder 201606L // also in <new>
132
  #define __cpp_lib_list_remove_return_type 201806L // also in <forward_list>, <list>
 
135
  #define __cpp_lib_make_reverse_iterator 201402L // also in <iterator>
136
  #define __cpp_lib_make_unique 201304L // also in <memory>
137
  #define __cpp_lib_map_try_emplace 201411L // also in <map>
138
  #define __cpp_lib_math_constants 201907L // also in <numbers>
139
  #define __cpp_lib_math_special_functions 201603L // also in <cmath>
140
+ #define __cpp_lib_mdspan 202207L // also in <mdspan>
141
  #define __cpp_lib_memory_resource 201603L // also in <memory_resource>
142
+ #define __cpp_lib_modules 202207L
143
+ #define __cpp_lib_move_iterator_concept 202207L // also in <iterator>
144
+ #define __cpp_lib_move_only_function 202110L // also in <functional>
145
  #define __cpp_lib_node_extract 201606L
146
  // also in <map>, <set>, <unordered_map>, <unordered_set>
147
  #define __cpp_lib_nonmember_container_access 201411L
148
  // also in <array>, <deque>, <forward_list>, <iterator>, <list>, <map>, <regex>, <set>, <string>,
149
  // <unordered_map>, <unordered_set>, <vector>
150
  #define __cpp_lib_not_fn 201603L // also in <functional>
151
  #define __cpp_lib_null_iterators 201304L // also in <iterator>
152
+ #define __cpp_lib_optional 202110L // also in <optional>
153
+ #define __cpp_lib_out_ptr 202106L // also in <memory>
154
  #define __cpp_lib_parallel_algorithm 201603L // also in <algorithm>, <numeric>
155
+ #define __cpp_lib_polymorphic_allocator 201902L // also in <memory_resource>
156
+ #define __cpp_lib_print 202207L // also in <print>, <ostream>
157
  #define __cpp_lib_quoted_string_io 201304L // also in <iomanip>
158
+ #define __cpp_lib_ranges 202302L
159
  // also in <algorithm>, <functional>, <iterator>, <memory>, <ranges>
160
+ #define __cpp_lib_ranges_as_const 202207L // also in <ranges>
161
+ #define __cpp_lib_ranges_as_rvalue 202207L // also in <ranges>
162
+ #define __cpp_lib_ranges_cartesian_product 202207L // also in <ranges>
163
+ #define __cpp_lib_ranges_chunk 202202L // also in <ranges>
164
+ #define __cpp_lib_ranges_chunk_by 202202L // also in <ranges>
165
+ #define __cpp_lib_ranges_contains 202207L // also in <algorithm>
166
+ #define __cpp_lib_ranges_enumerate 202302L // also in <ranges>, <version>
167
+ #define __cpp_lib_ranges_find_last 202207L // also in <algorithm>
168
+ #define __cpp_lib_ranges_fold 202207L // also in <algorithm>
169
+ #define __cpp_lib_ranges_iota 202202L // also in <numeric>
170
+ #define __cpp_lib_ranges_join_with 202202L // also in <ranges>
171
+ #define __cpp_lib_ranges_repeat 202207L // also in <ranges>
172
+ #define __cpp_lib_ranges_slide 202202L // also in <ranges>
173
+ #define __cpp_lib_ranges_starts_ends_with 202106L // also in <algorithm>
174
+ #define __cpp_lib_ranges_stride 202207L // also in <ranges>
175
+ #define __cpp_lib_ranges_to_container 202202L // also in <ranges>
176
+ #define __cpp_lib_ranges_zip 202110L // also in <ranges>, <tuple>, <utility>
177
  #define __cpp_lib_raw_memory_algorithms 201606L // also in <memory>
178
+ #define __cpp_lib_reference_from_temporary 202202L // also in <type_traits>
179
  #define __cpp_lib_remove_cvref 201711L // also in <type_traits>
180
  #define __cpp_lib_result_of_sfinae 201210L // also in <functional>, <type_traits>
181
  #define __cpp_lib_robust_nonmodifying_seq_ops 201304L // also in <algorithm>
182
  #define __cpp_lib_sample 201603L // also in <algorithm>
183
  #define __cpp_lib_scoped_lock 201703L // also in <mutex>
184
  #define __cpp_lib_semaphore 201907L // also in <semaphore>
185
  #define __cpp_lib_shared_mutex 201505L // also in <shared_mutex>
186
  #define __cpp_lib_shared_ptr_arrays 201707L // also in <memory>
187
  #define __cpp_lib_shared_ptr_weak_type 201606L // also in <memory>
188
  #define __cpp_lib_shared_timed_mutex 201402L // also in <shared_mutex>
189
+ #define __cpp_lib_shift 202202L // also in <algorithm>
190
  #define __cpp_lib_smart_ptr_for_overwrite 202002L // also in <memory>
191
  #define __cpp_lib_source_location 201907L // also in <source_location>
192
  #define __cpp_lib_span 202002L // also in <span>
193
+ #define __cpp_lib_spanstream 202106L // also in <spanstream>
194
  #define __cpp_lib_ssize 201902L // also in <iterator>
195
+ #define __cpp_lib_stacktrace 202011L // also in <stacktrace>
196
+ #define __cpp_lib_start_lifetime_as 202207L // also in <memory>
197
  #define __cpp_lib_starts_ends_with 201711L // also in <string>, <string_view>
198
+ #define __cpp_lib_stdatomic_h 202011L // also in <stdatomic.h>
199
+ #define __cpp_lib_string_contains 202011L // also in <string>, <string_view>
200
+ #define __cpp_lib_string_resize_and_overwrite 202110L // also in <string>
201
  #define __cpp_lib_string_udls 201304L // also in <string>
202
  #define __cpp_lib_string_view 201803L // also in <string>, <string_view>
203
  #define __cpp_lib_syncbuf 201803L // also in <syncstream>
204
  #define __cpp_lib_three_way_comparison 201907L // also in <compare>
205
  #define __cpp_lib_to_address 201711L // also in <memory>
206
  #define __cpp_lib_to_array 201907L // also in <array>
207
  #define __cpp_lib_to_chars 201611L // also in <charconv>
208
+ #define __cpp_lib_to_underlying 202102L // also in <utility>
209
  #define __cpp_lib_transformation_trait_aliases 201304L // also in <type_traits>
210
  #define __cpp_lib_transparent_operators 201510L // also in <memory>, <functional>
211
+ #define __cpp_lib_tuple_like 202207L
212
+ // also in <utility>, <tuple>, <map>, <unordered_map>
213
  #define __cpp_lib_tuple_element_t 201402L // also in <tuple>
214
  #define __cpp_lib_tuples_by_type 201304L // also in <utility>, <tuple>
215
  #define __cpp_lib_type_identity 201806L // also in <type_traits>
216
  #define __cpp_lib_type_trait_variable_templates 201510L // also in <type_traits>
217
  #define __cpp_lib_uncaught_exceptions 201411L // also in <exception>
218
  #define __cpp_lib_unordered_map_try_emplace 201411L // also in <unordered_map>
219
+ #define __cpp_lib_unreachable 202202L // also in <utility>
220
  #define __cpp_lib_unwrap_ref 201811L // also in <type_traits>
221
+ #define __cpp_lib_variant 202106L // also in <variant>
222
  #define __cpp_lib_void_t 201411L // also in <type_traits>
223
  ```
224
 
225
  ### Header `<limits>` synopsis <a id="limits.syn">[[limits.syn]]</a>
226
 
227
  ``` cpp
228
+ // all freestanding
229
  namespace std {
230
+ // [round.style], enumeration float_round_style
231
  enum float_round_style;
 
232
 
233
  // [numeric.limits], class template numeric_limits
234
  template<class T> class numeric_limits;
235
 
236
  template<class T> class numeric_limits<const T>;
 
260
  template<> class numeric_limits<double>;
261
  template<> class numeric_limits<long double>;
262
  }
263
  ```
264
 
265
+ ### Enum `float_round_style` <a id="round.style">[[round.style]]</a>
 
 
266
 
267
  ``` cpp
268
  namespace std {
269
  enum float_round_style {
270
  round_indeterminate = -1,
 
285
  representable value
286
  - `round_toward_infinity` if the rounding style is toward infinity
287
  - `round_toward_neg_infinity` if the rounding style is toward negative
288
  infinity
289
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
290
  ### Class template `numeric_limits` <a id="numeric.limits">[[numeric.limits]]</a>
291
 
292
+ #### General <a id="numeric.limits.general">[[numeric.limits.general]]</a>
293
+
294
  The `numeric_limits` class template provides a C++ program with
295
  information about various properties of the implementation’s
296
  representation of the arithmetic types.
297
 
298
  ``` cpp
 
320
  static constexpr int max_exponent10 = 0;
321
 
322
  static constexpr bool has_infinity = false;
323
  static constexpr bool has_quiet_NaN = false;
324
  static constexpr bool has_signaling_NaN = false;
 
 
325
  static constexpr T infinity() noexcept { return T(); }
326
  static constexpr T quiet_NaN() noexcept { return T(); }
327
  static constexpr T signaling_NaN() noexcept { return T(); }
328
  static constexpr T denorm_min() noexcept { return T(); }
329
 
 
340
 
341
  For all members declared `static` `constexpr` in the `numeric_limits`
342
  template, specializations shall define these values in such a way that
343
  they are usable as constant expressions.
344
 
345
+ For the `numeric_limits` primary template, all data members are
346
+ value-initialized and all member functions return a value-initialized
347
+ object.
348
+
349
+ [*Note 1*: This means all members have zero or `false` values unless
350
+ `numeric_limits` is specialized for a type. — *end note*]
351
 
352
  Specializations shall be provided for each arithmetic type, both
353
  floating-point and integer, including `bool`. The member
354
  `is_specialized` shall be `true` for all such specializations of
355
  `numeric_limits`.
 
541
 
542
  Meaningful for all floating-point types.
543
 
544
  Shall be `true` for all specializations in which `is_iec559 != false`.
545
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
546
  ``` cpp
547
  static constexpr T infinity() noexcept;
548
  ```
549
 
550
+ Representation of positive infinity, if available.[^18]
551
 
552
  Meaningful for all specializations for which `has_infinity != false`.
553
  Required in specializations for which `is_iec559 != false`.
554
 
555
  ``` cpp
556
  static constexpr T quiet_NaN() noexcept;
557
  ```
558
 
559
+ Representation of a quiet “Not a Number”, if available.[^19]
560
 
561
  Meaningful for all specializations for which `has_quiet_NaN != false`.
562
  Required in specializations for which `is_iec559 != false`.
563
 
564
  ``` cpp
565
  static constexpr T signaling_NaN() noexcept;
566
  ```
567
 
568
+ Representation of a signaling “Not a Number”, if available.[^20]
569
 
570
  Meaningful for all specializations for which
571
  `has_signaling_NaN != false`. Required in specializations for which
572
  `is_iec559 != false`.
573
 
574
  ``` cpp
575
  static constexpr T denorm_min() noexcept;
576
  ```
577
 
578
+ Minimum positive subnormal value, if available.[^21]
579
+
580
+ Otherwise, minimum positive normalized value.
581
 
582
  Meaningful for all floating-point types.
583
 
 
 
 
584
  ``` cpp
585
  static constexpr bool is_iec559;
586
  ```
587
 
588
+ `true` if and only if the type adheres to ISO/IEC/IEEE 60559.[^22]
589
+
590
+ [*Note 1*: The value is `true` for any of the types `float16_t`,
591
+ `float32_t`, `float64_t`, or `float128_t`, if
592
+ present [[basic.extended.fp]]. — *end note*]
593
 
594
  Meaningful for all floating-point types.
595
 
596
  ``` cpp
597
  static constexpr bool is_bounded;
598
  ```
599
 
600
+ `true` if the set of values representable by the type is finite.[^23]
601
 
602
+ [*Note 2*: All fundamental types [[basic.fundamental]] are bounded.
603
  This member would be `false` for arbitrary precision
604
  types. — *end note*]
605
 
606
  Meaningful for all specializations.
607
 
608
  ``` cpp
609
  static constexpr bool is_modulo;
610
  ```
611
 
612
+ `true` if the type is modulo.[^24]
613
+
614
+ A type is modulo if, for any operation involving `+`, `-`, or `*` on
615
+ values of that type whose result would fall outside the range \[`min()`,
616
+ `max()`\], the value returned differs from the true value by an integer
617
+ multiple of `max() - min() + 1`.
618
 
619
  [*Example 1*: `is_modulo` is `false` for signed integer
620
  types [[basic.fundamental]] unless an implementation, as an extension to
621
  this document, defines signed integer overflow to
622
  wrap. — *end example*]
 
626
  ``` cpp
627
  static constexpr bool traps;
628
  ```
629
 
630
  `true` if, at the start of the program, there exists a value of the type
631
+ that would cause an arithmetic operation using that value to trap.[^25]
632
 
633
  Meaningful for all specializations.
634
 
635
  ``` cpp
636
  static constexpr bool tinyness_before;
637
  ```
638
 
639
+ `true` if tinyness is detected before rounding.[^26]
640
 
641
  Meaningful for all floating-point types.
642
 
643
  ``` cpp
644
  static constexpr float_round_style round_style;
645
  ```
646
 
647
+ The rounding style for the type.[^27]
648
 
649
  Meaningful for all floating-point types. Specializations for integer
650
  types shall return `round_toward_zero`.
651
 
652
  #### `numeric_limits` specializations <a id="numeric.special">[[numeric.special]]</a>
 
686
  static constexpr int max_exponent10 = + 38;
687
 
688
  static constexpr bool has_infinity = true;
689
  static constexpr bool has_quiet_NaN = true;
690
  static constexpr bool has_signaling_NaN = true;
 
 
691
 
692
  static constexpr float infinity() noexcept { return value; }
693
  static constexpr float quiet_NaN() noexcept { return value; }
694
  static constexpr float signaling_NaN() noexcept { return value; }
695
  static constexpr float denorm_min() noexcept { return min(); }
 
735
  static constexpr int max_exponent10 = 0;
736
 
737
  static constexpr bool has_infinity = false;
738
  static constexpr bool has_quiet_NaN = false;
739
  static constexpr bool has_signaling_NaN = false;
 
 
740
  static constexpr bool infinity() noexcept { return 0; }
741
  static constexpr bool quiet_NaN() noexcept { return 0; }
742
  static constexpr bool signaling_NaN() noexcept { return 0; }
743
  static constexpr bool denorm_min() noexcept { return 0; }
744
 
 
754
  ```
755
 
756
  ### Header `<climits>` synopsis <a id="climits.syn">[[climits.syn]]</a>
757
 
758
  ``` cpp
759
+ // all freestanding
760
  #define CHAR_BIT see below
761
  #define SCHAR_MIN see below
762
  #define SCHAR_MAX see below
763
  #define UCHAR_MAX see below
764
  #define CHAR_MIN see below
 
779
  ```
780
 
781
  The header `<climits>` defines all macros the same as the C standard
782
  library header `<limits.h>`.
783
 
784
+ [*Note 1*: Except for `CHAR_BIT` and `MB_LEN_MAX`, a macro referring to
785
+ an integer type `T` defines a constant whose type is the promoted type
786
+ of `T` [[conv.prom]]. — *end note*]
787
 
788
  See also: ISO C 5.2.4.2.1
789
 
790
  ### Header `<cfloat>` synopsis <a id="cfloat.syn">[[cfloat.syn]]</a>
791
 
792
  ``` cpp
793
+ // all freestanding
794
  #define FLT_ROUNDS see below
795
  #define FLT_EVAL_METHOD see below
796
  #define FLT_HAS_SUBNORM see below
797
  #define DBL_HAS_SUBNORM see below
798
  #define LDBL_HAS_SUBNORM see below