libcxx/docs/FeatureTestMacroTable.rst

   1 .. _FeatureTestMacroTable:
   2
   3 ==========================
   4 Feature Test Macro Support
   5 ==========================
   6
   7 .. contents::
   8    :local:
   9
  10 Overview
  11 ========
  12
  13 This file documents the feature test macros currently supported by libc++.
  14
  15 .. _feature-status:
  16
  17 Status
  18 ======
  19
  20 .. table:: Current Status
  21     :name: feature-status-table
  22     :widths: auto
  23
  24     ========================================================== =================
  25     Macro Name                                                 Value
  26     ========================================================== =================
  27     **C++14**
  28     ----------------------------------------------------------------------------
  29     ``__cpp_lib_chrono_udls``                                  ``201304L``
  30     ---------------------------------------------------------- -----------------
  31     ``__cpp_lib_complex_udls``                                 ``201309L``
  32     ---------------------------------------------------------- -----------------
  33     ``__cpp_lib_exchange_function``                            ``201304L``
  34     ---------------------------------------------------------- -----------------
  35     ``__cpp_lib_generic_associative_lookup``                   ``201304L``
  36     ---------------------------------------------------------- -----------------
  37     ``__cpp_lib_integer_sequence``                             ``201304L``
  38     ---------------------------------------------------------- -----------------
  39     ``__cpp_lib_integral_constant_callable``                   ``201304L``
  40     ---------------------------------------------------------- -----------------
  41     ``__cpp_lib_is_final``                                     ``201402L``
  42     ---------------------------------------------------------- -----------------
  43     ``__cpp_lib_is_null_pointer``                              ``201309L``
  44     ---------------------------------------------------------- -----------------
  45     ``__cpp_lib_make_reverse_iterator``                        ``201402L``
  46     ---------------------------------------------------------- -----------------
  47     ``__cpp_lib_make_unique``                                  ``201304L``
  48     ---------------------------------------------------------- -----------------
  49     ``__cpp_lib_null_iterators``                               ``201304L``
  50     ---------------------------------------------------------- -----------------
  51     ``__cpp_lib_quoted_string_io``                             ``201304L``
  52     ---------------------------------------------------------- -----------------
  53     ``__cpp_lib_result_of_sfinae``                             ``201210L``
  54     ---------------------------------------------------------- -----------------
  55     ``__cpp_lib_robust_nonmodifying_seq_ops``                  ``201304L``
  56     ---------------------------------------------------------- -----------------
  57     ``__cpp_lib_shared_timed_mutex``                           ``201402L``
  58     ---------------------------------------------------------- -----------------
  59     ``__cpp_lib_string_udls``                                  ``201304L``
  60     ---------------------------------------------------------- -----------------
  61     ``__cpp_lib_transformation_trait_aliases``                 ``201304L``
  62     ---------------------------------------------------------- -----------------
  63     ``__cpp_lib_transparent_operators``                        ``201210L``
  64     ---------------------------------------------------------- -----------------
  65     ``__cpp_lib_tuple_element_t``                              ``201402L``
  66     ---------------------------------------------------------- -----------------
  67     ``__cpp_lib_tuples_by_type``                               ``201304L``
  68     ---------------------------------------------------------- -----------------
  69     **C++17**
  70     ----------------------------------------------------------------------------
  71     ``__cpp_lib_addressof_constexpr``                          ``201603L``
  72     ---------------------------------------------------------- -----------------
  73     ``__cpp_lib_allocator_traits_is_always_equal``             ``201411L``
  74     ---------------------------------------------------------- -----------------
  75     ``__cpp_lib_any``                                          ``201606L``
  76     ---------------------------------------------------------- -----------------
  77     ``__cpp_lib_apply``                                        ``201603L``
  78     ---------------------------------------------------------- -----------------
  79     ``__cpp_lib_array_constexpr``                              ``201603L``
  80     ---------------------------------------------------------- -----------------
  81     ``__cpp_lib_as_const``                                     ``201510L``
  82     ---------------------------------------------------------- -----------------
  83     ``__cpp_lib_atomic_is_always_lock_free``                   ``201603L``
  84     ---------------------------------------------------------- -----------------
  85     ``__cpp_lib_bool_constant``                                ``201505L``
  86     ---------------------------------------------------------- -----------------
  87     ``__cpp_lib_boyer_moore_searcher``                         ``201603L``
  88     ---------------------------------------------------------- -----------------
  89     ``__cpp_lib_byte``                                         ``201603L``
  90     ---------------------------------------------------------- -----------------
  91     ``__cpp_lib_chrono``                                       ``201611L``
  92     ---------------------------------------------------------- -----------------
  93     ``__cpp_lib_clamp``                                        ``201603L``
  94     ---------------------------------------------------------- -----------------
  95     ``__cpp_lib_enable_shared_from_this``                      ``201603L``
  96     ---------------------------------------------------------- -----------------
  97     ``__cpp_lib_execution``                                    *unimplemented*
  98     ---------------------------------------------------------- -----------------
  99     ``__cpp_lib_filesystem``                                   ``201703L``
 100     ---------------------------------------------------------- -----------------
 101     ``__cpp_lib_gcd_lcm``                                      ``201606L``
 102     ---------------------------------------------------------- -----------------
 103     ``__cpp_lib_hardware_interference_size``                   ``201703L``
 104     ---------------------------------------------------------- -----------------
 105     ``__cpp_lib_has_unique_object_representations``            ``201606L``
 106     ---------------------------------------------------------- -----------------
 107     ``__cpp_lib_hypot``                                        ``201603L``
 108     ---------------------------------------------------------- -----------------
 109     ``__cpp_lib_incomplete_container_elements``                ``201505L``
 110     ---------------------------------------------------------- -----------------
 111     ``__cpp_lib_invoke``                                       ``201411L``
 112     ---------------------------------------------------------- -----------------
 113     ``__cpp_lib_is_aggregate``                                 ``201703L``
 114     ---------------------------------------------------------- -----------------
 115     ``__cpp_lib_is_invocable``                                 ``201703L``
 116     ---------------------------------------------------------- -----------------
 117     ``__cpp_lib_is_swappable``                                 ``201603L``
 118     ---------------------------------------------------------- -----------------
 119     ``__cpp_lib_launder``                                      ``201606L``
 120     ---------------------------------------------------------- -----------------
 121     ``__cpp_lib_logical_traits``                               ``201510L``
 122     ---------------------------------------------------------- -----------------
 123     ``__cpp_lib_make_from_tuple``                              ``201606L``
 124     ---------------------------------------------------------- -----------------
 125     ``__cpp_lib_map_try_emplace``                              ``201411L``
 126     ---------------------------------------------------------- -----------------
 127     ``__cpp_lib_math_special_functions``                       *unimplemented*
 128     ---------------------------------------------------------- -----------------
 129     ``__cpp_lib_memory_resource``                              ``201603L``
 130     ---------------------------------------------------------- -----------------
 131     ``__cpp_lib_node_extract``                                 ``201606L``
 132     ---------------------------------------------------------- -----------------
 133     ``__cpp_lib_nonmember_container_access``                   ``201411L``
 134     ---------------------------------------------------------- -----------------
 135     ``__cpp_lib_not_fn``                                       ``201603L``
 136     ---------------------------------------------------------- -----------------
 137     ``__cpp_lib_optional``                                     ``201606L``
 138     ---------------------------------------------------------- -----------------
 139     ``__cpp_lib_parallel_algorithm``                           *unimplemented*
 140     ---------------------------------------------------------- -----------------
 141     ``__cpp_lib_raw_memory_algorithms``                        ``201606L``
 142     ---------------------------------------------------------- -----------------
 143     ``__cpp_lib_sample``                                       ``201603L``
 144     ---------------------------------------------------------- -----------------
 145     ``__cpp_lib_scoped_lock``                                  ``201703L``
 146     ---------------------------------------------------------- -----------------
 147     ``__cpp_lib_shared_mutex``                                 ``201505L``
 148     ---------------------------------------------------------- -----------------
 149     ``__cpp_lib_shared_ptr_arrays``                            ``201611L``
 150     ---------------------------------------------------------- -----------------
 151     ``__cpp_lib_shared_ptr_weak_type``                         ``201606L``
 152     ---------------------------------------------------------- -----------------
 153     ``__cpp_lib_string_view``                                  ``201606L``
 154     ---------------------------------------------------------- -----------------
 155     ``__cpp_lib_to_chars``                                     *unimplemented*
 156     ---------------------------------------------------------- -----------------
 157     ``__cpp_lib_transparent_operators``                        ``201510L``
 158     ---------------------------------------------------------- -----------------
 159     ``__cpp_lib_type_trait_variable_templates``                ``201510L``
 160     ---------------------------------------------------------- -----------------
 161     ``__cpp_lib_uncaught_exceptions``                          ``201411L``
 162     ---------------------------------------------------------- -----------------
 163     ``__cpp_lib_unordered_map_try_emplace``                    ``201411L``
 164     ---------------------------------------------------------- -----------------
 165     ``__cpp_lib_variant``                                      ``202102L``
 166     ---------------------------------------------------------- -----------------
 167     ``__cpp_lib_void_t``                                       ``201411L``
 168     ---------------------------------------------------------- -----------------
 169     **C++20**
 170     ----------------------------------------------------------------------------
 171     ``__cpp_lib_array_constexpr``                              ``201811L``
 172     ---------------------------------------------------------- -----------------
 173     ``__cpp_lib_assume_aligned``                               ``201811L``
 174     ---------------------------------------------------------- -----------------
 175     ``__cpp_lib_atomic_flag_test``                             ``201907L``
 176     ---------------------------------------------------------- -----------------
 177     ``__cpp_lib_atomic_float``                                 *unimplemented*
 178     ---------------------------------------------------------- -----------------
 179     ``__cpp_lib_atomic_lock_free_type_aliases``                ``201907L``
 180     ---------------------------------------------------------- -----------------
 181     ``__cpp_lib_atomic_ref``                                   ``201806L``
 182     ---------------------------------------------------------- -----------------
 183     ``__cpp_lib_atomic_shared_ptr``                            *unimplemented*
 184     ---------------------------------------------------------- -----------------
 185     ``__cpp_lib_atomic_value_initialization``                  ``201911L``
 186     ---------------------------------------------------------- -----------------
 187     ``__cpp_lib_atomic_wait``                                  ``201907L``
 188     ---------------------------------------------------------- -----------------
 189     ``__cpp_lib_barrier``                                      ``201907L``
 190     ---------------------------------------------------------- -----------------
 191     ``__cpp_lib_bind_front``                                   ``201907L``
 192     ---------------------------------------------------------- -----------------
 193     ``__cpp_lib_bit_cast``                                     ``201806L``
 194     ---------------------------------------------------------- -----------------
 195     ``__cpp_lib_bitops``                                       ``201907L``
 196     ---------------------------------------------------------- -----------------
 197     ``__cpp_lib_bounded_array_traits``                         ``201902L``
 198     ---------------------------------------------------------- -----------------
 199     ``__cpp_lib_char8_t``                                      ``201907L``
 200     ---------------------------------------------------------- -----------------
 201     ``__cpp_lib_concepts``                                     ``202002L``
 202     ---------------------------------------------------------- -----------------
 203     ``__cpp_lib_constexpr_algorithms``                         ``201806L``
 204     ---------------------------------------------------------- -----------------
 205     ``__cpp_lib_constexpr_complex``                            ``201711L``
 206     ---------------------------------------------------------- -----------------
 207     ``__cpp_lib_constexpr_dynamic_alloc``                      ``201907L``
 208     ---------------------------------------------------------- -----------------
 209     ``__cpp_lib_constexpr_functional``                         ``201907L``
 210     ---------------------------------------------------------- -----------------
 211     ``__cpp_lib_constexpr_iterator``                           ``201811L``
 212     ---------------------------------------------------------- -----------------
 213     ``__cpp_lib_constexpr_memory``                             ``201811L``
 214     ---------------------------------------------------------- -----------------
 215     ``__cpp_lib_constexpr_numeric``                            ``201911L``
 216     ---------------------------------------------------------- -----------------
 217     ``__cpp_lib_constexpr_string``                             ``201907L``
 218     ---------------------------------------------------------- -----------------
 219     ``__cpp_lib_constexpr_string_view``                        ``201811L``
 220     ---------------------------------------------------------- -----------------
 221     ``__cpp_lib_constexpr_tuple``                              ``201811L``
 222     ---------------------------------------------------------- -----------------
 223     ``__cpp_lib_constexpr_utility``                            ``201811L``
 224     ---------------------------------------------------------- -----------------
 225     ``__cpp_lib_constexpr_vector``                             ``201907L``
 226     ---------------------------------------------------------- -----------------
 227     ``__cpp_lib_coroutine``                                    ``201902L``
 228     ---------------------------------------------------------- -----------------
 229     ``__cpp_lib_destroying_delete``                            ``201806L``
 230     ---------------------------------------------------------- -----------------
 231     ``__cpp_lib_endian``                                       ``201907L``
 232     ---------------------------------------------------------- -----------------
 233     ``__cpp_lib_erase_if``                                     ``202002L``
 234     ---------------------------------------------------------- -----------------
 235     ``__cpp_lib_execution``                                    *unimplemented*
 236     ---------------------------------------------------------- -----------------
 237     ``__cpp_lib_format``                                       ``202110L``
 238     ---------------------------------------------------------- -----------------
 239     ``__cpp_lib_format_uchar``                                 ``202311L``
 240     ---------------------------------------------------------- -----------------
 241     ``__cpp_lib_generic_unordered_lookup``                     ``201811L``
 242     ---------------------------------------------------------- -----------------
 243     ``__cpp_lib_int_pow2``                                     ``202002L``
 244     ---------------------------------------------------------- -----------------
 245     ``__cpp_lib_integer_comparison_functions``                 ``202002L``
 246     ---------------------------------------------------------- -----------------
 247     ``__cpp_lib_interpolate``                                  ``201902L``
 248     ---------------------------------------------------------- -----------------
 249     ``__cpp_lib_is_constant_evaluated``                        ``201811L``
 250     ---------------------------------------------------------- -----------------
 251     ``__cpp_lib_is_layout_compatible``                         *unimplemented*
 252     ---------------------------------------------------------- -----------------
 253     ``__cpp_lib_is_nothrow_convertible``                       ``201806L``
 254     ---------------------------------------------------------- -----------------
 255     ``__cpp_lib_is_pointer_interconvertible``                  *unimplemented*
 256     ---------------------------------------------------------- -----------------
 257     ``__cpp_lib_jthread``                                      ``201911L``
 258     ---------------------------------------------------------- -----------------
 259     ``__cpp_lib_latch``                                        ``201907L``
 260     ---------------------------------------------------------- -----------------
 261     ``__cpp_lib_list_remove_return_type``                      ``201806L``
 262     ---------------------------------------------------------- -----------------
 263     ``__cpp_lib_math_constants``                               ``201907L``
 264     ---------------------------------------------------------- -----------------
 265     ``__cpp_lib_move_iterator_concept``                        ``202207L``
 266     ---------------------------------------------------------- -----------------
 267     ``__cpp_lib_optional``                                     ``202106L``
 268     ---------------------------------------------------------- -----------------
 269     ``__cpp_lib_polymorphic_allocator``                        ``201902L``
 270     ---------------------------------------------------------- -----------------
 271     ``__cpp_lib_ranges``                                       ``202110L``
 272     ---------------------------------------------------------- -----------------
 273     ``__cpp_lib_remove_cvref``                                 ``201711L``
 274     ---------------------------------------------------------- -----------------
 275     ``__cpp_lib_semaphore``                                    ``201907L``
 276     ---------------------------------------------------------- -----------------
 277     ``__cpp_lib_shared_ptr_arrays``                            ``201707L``
 278     ---------------------------------------------------------- -----------------
 279     ``__cpp_lib_shift``                                        ``201806L``
 280     ---------------------------------------------------------- -----------------
 281     ``__cpp_lib_smart_ptr_for_overwrite``                      ``202002L``
 282     ---------------------------------------------------------- -----------------
 283     ``__cpp_lib_source_location``                              ``201907L``
 284     ---------------------------------------------------------- -----------------
 285     ``__cpp_lib_span``                                         ``202002L``
 286     ---------------------------------------------------------- -----------------
 287     ``__cpp_lib_ssize``                                        ``201902L``
 288     ---------------------------------------------------------- -----------------
 289     ``__cpp_lib_starts_ends_with``                             ``201711L``
 290     ---------------------------------------------------------- -----------------
 291     ``__cpp_lib_string_view``                                  ``201803L``
 292     ---------------------------------------------------------- -----------------
 293     ``__cpp_lib_syncbuf``                                      ``201803L``
 294     ---------------------------------------------------------- -----------------
 295     ``__cpp_lib_three_way_comparison``                         ``201907L``
 296     ---------------------------------------------------------- -----------------
 297     ``__cpp_lib_to_address``                                   ``201711L``
 298     ---------------------------------------------------------- -----------------
 299     ``__cpp_lib_to_array``                                     ``201907L``
 300     ---------------------------------------------------------- -----------------
 301     ``__cpp_lib_type_identity``                                ``201806L``
 302     ---------------------------------------------------------- -----------------
 303     ``__cpp_lib_unwrap_ref``                                   ``201811L``
 304     ---------------------------------------------------------- -----------------
 305     ``__cpp_lib_variant``                                      ``202106L``
 306     ---------------------------------------------------------- -----------------
 307     **C++23**
 308     ----------------------------------------------------------------------------
 309     ``__cpp_lib_adaptor_iterator_pair_constructor``            ``202106L``
 310     ---------------------------------------------------------- -----------------
 311     ``__cpp_lib_allocate_at_least``                            ``202302L``
 312     ---------------------------------------------------------- -----------------
 313     ``__cpp_lib_associative_heterogeneous_erasure``            *unimplemented*
 314     ---------------------------------------------------------- -----------------
 315     ``__cpp_lib_bind_back``                                    ``202202L``
 316     ---------------------------------------------------------- -----------------
 317     ``__cpp_lib_byteswap``                                     ``202110L``
 318     ---------------------------------------------------------- -----------------
 319     ``__cpp_lib_constexpr_bitset``                             ``202207L``
 320     ---------------------------------------------------------- -----------------
 321     ``__cpp_lib_constexpr_charconv``                           ``202207L``
 322     ---------------------------------------------------------- -----------------
 323     ``__cpp_lib_constexpr_cmath``                              *unimplemented*
 324     ---------------------------------------------------------- -----------------
 325     ``__cpp_lib_constexpr_memory``                             ``202202L``
 326     ---------------------------------------------------------- -----------------
 327     ``__cpp_lib_constexpr_typeinfo``                           ``202106L``
 328     ---------------------------------------------------------- -----------------
 329     ``__cpp_lib_containers_ranges``                            ``202202L``
 330     ---------------------------------------------------------- -----------------
 331     ``__cpp_lib_expected``                                     ``202211L``
 332     ---------------------------------------------------------- -----------------
 333     ``__cpp_lib_format_ranges``                                ``202207L``
 334     ---------------------------------------------------------- -----------------
 335     ``__cpp_lib_formatters``                                   *unimplemented*
 336     ---------------------------------------------------------- -----------------
 337     ``__cpp_lib_forward_like``                                 ``202207L``
 338     ---------------------------------------------------------- -----------------
 339     ``__cpp_lib_invoke_r``                                     ``202106L``
 340     ---------------------------------------------------------- -----------------
 341     ``__cpp_lib_ios_noreplace``                                ``202207L``
 342     ---------------------------------------------------------- -----------------
 343     ``__cpp_lib_is_implicit_lifetime``                         ``202302L``
 344     ---------------------------------------------------------- -----------------
 345     ``__cpp_lib_is_scoped_enum``                               ``202011L``
 346     ---------------------------------------------------------- -----------------
 347     ``__cpp_lib_mdspan``                                       ``202207L``
 348     ---------------------------------------------------------- -----------------
 349     ``__cpp_lib_modules``                                      ``202207L``
 350     ---------------------------------------------------------- -----------------
 351     ``__cpp_lib_move_only_function``                           *unimplemented*
 352     ---------------------------------------------------------- -----------------
 353     ``__cpp_lib_optional``                                     ``202110L``
 354     ---------------------------------------------------------- -----------------
 355     ``__cpp_lib_out_ptr``                                      ``202106L``
 356     ---------------------------------------------------------- -----------------
 357     ``__cpp_lib_print``                                        ``202207L``
 358     ---------------------------------------------------------- -----------------
 359     ``__cpp_lib_ranges``                                       ``202406L``
 360     ---------------------------------------------------------- -----------------
 361     ``__cpp_lib_ranges_as_const``                              *unimplemented*
 362     ---------------------------------------------------------- -----------------
 363     ``__cpp_lib_ranges_as_rvalue``                             ``202207L``
 364     ---------------------------------------------------------- -----------------
 365     ``__cpp_lib_ranges_chunk``                                 *unimplemented*
 366     ---------------------------------------------------------- -----------------
 367     ``__cpp_lib_ranges_chunk_by``                              ``202202L``
 368     ---------------------------------------------------------- -----------------
 369     ``__cpp_lib_ranges_contains``                              ``202207L``
 370     ---------------------------------------------------------- -----------------
 371     ``__cpp_lib_ranges_find_last``                             ``202207L``
 372     ---------------------------------------------------------- -----------------
 373     ``__cpp_lib_ranges_iota``                                  *unimplemented*
 374     ---------------------------------------------------------- -----------------
 375     ``__cpp_lib_ranges_join_with``                             *unimplemented*
 376     ---------------------------------------------------------- -----------------
 377     ``__cpp_lib_ranges_repeat``                                ``202207L``
 378     ---------------------------------------------------------- -----------------
 379     ``__cpp_lib_ranges_slide``                                 *unimplemented*
 380     ---------------------------------------------------------- -----------------
 381     ``__cpp_lib_ranges_starts_ends_with``                      ``202106L``
 382     ---------------------------------------------------------- -----------------
 383     ``__cpp_lib_ranges_to_container``                          ``202202L``
 384     ---------------------------------------------------------- -----------------
 385     ``__cpp_lib_ranges_zip``                                   *unimplemented*
 386     ---------------------------------------------------------- -----------------
 387     ``__cpp_lib_reference_from_temporary``                     *unimplemented*
 388     ---------------------------------------------------------- -----------------
 389     ``__cpp_lib_spanstream``                                   *unimplemented*
 390     ---------------------------------------------------------- -----------------
 391     ``__cpp_lib_stacktrace``                                   *unimplemented*
 392     ---------------------------------------------------------- -----------------
 393     ``__cpp_lib_stdatomic_h``                                  ``202011L``
 394     ---------------------------------------------------------- -----------------
 395     ``__cpp_lib_string_contains``                              ``202011L``
 396     ---------------------------------------------------------- -----------------
 397     ``__cpp_lib_string_resize_and_overwrite``                  ``202110L``
 398     ---------------------------------------------------------- -----------------
 399     ``__cpp_lib_to_underlying``                                ``202102L``
 400     ---------------------------------------------------------- -----------------
 401     ``__cpp_lib_tuple_like``                                   *unimplemented*
 402     ---------------------------------------------------------- -----------------
 403     ``__cpp_lib_unreachable``                                  ``202202L``
 404     ---------------------------------------------------------- -----------------
 405     **C++26**
 406     ----------------------------------------------------------------------------
 407     ``__cpp_lib_associative_heterogeneous_insertion``          *unimplemented*
 408     ---------------------------------------------------------- -----------------
 409     ``__cpp_lib_atomic_min_max``                               *unimplemented*
 410     ---------------------------------------------------------- -----------------
 411     ``__cpp_lib_bind_front``                                   ``202306L``
 412     ---------------------------------------------------------- -----------------
 413     ``__cpp_lib_bitset``                                       ``202306L``
 414     ---------------------------------------------------------- -----------------
 415     ``__cpp_lib_constexpr_new``                                ``202406L``
 416     ---------------------------------------------------------- -----------------
 417     ``__cpp_lib_constrained_equality``                         *unimplemented*
 418     ---------------------------------------------------------- -----------------
 419     ``__cpp_lib_copyable_function``                            *unimplemented*
 420     ---------------------------------------------------------- -----------------
 421     ``__cpp_lib_debugging``                                    *unimplemented*
 422     ---------------------------------------------------------- -----------------
 423     ``__cpp_lib_default_template_type_for_algorithm_values``   *unimplemented*
 424     ---------------------------------------------------------- -----------------
 425     ``__cpp_lib_format_path``                                  *unimplemented*
 426     ---------------------------------------------------------- -----------------
 427     ``__cpp_lib_freestanding_algorithm``                       *unimplemented*
 428     ---------------------------------------------------------- -----------------
 429     ``__cpp_lib_freestanding_array``                           *unimplemented*
 430     ---------------------------------------------------------- -----------------
 431     ``__cpp_lib_freestanding_cstring``                         *unimplemented*
 432     ---------------------------------------------------------- -----------------
 433     ``__cpp_lib_freestanding_expected``                        *unimplemented*
 434     ---------------------------------------------------------- -----------------
 435     ``__cpp_lib_freestanding_mdspan``                          *unimplemented*
 436     ---------------------------------------------------------- -----------------
 437     ``__cpp_lib_freestanding_optional``                        *unimplemented*
 438     ---------------------------------------------------------- -----------------
 439     ``__cpp_lib_freestanding_string_view``                     *unimplemented*
 440     ---------------------------------------------------------- -----------------
 441     ``__cpp_lib_freestanding_variant``                         *unimplemented*
 442     ---------------------------------------------------------- -----------------
 443     ``__cpp_lib_fstream_native_handle``                        ``202306L``
 444     ---------------------------------------------------------- -----------------
 445     ``__cpp_lib_function_ref``                                 *unimplemented*
 446     ---------------------------------------------------------- -----------------
 447     ``__cpp_lib_generate_random``                              *unimplemented*
 448     ---------------------------------------------------------- -----------------
 449     ``__cpp_lib_hazard_pointer``                               *unimplemented*
 450     ---------------------------------------------------------- -----------------
 451     ``__cpp_lib_inplace_vector``                               *unimplemented*
 452     ---------------------------------------------------------- -----------------
 453     ``__cpp_lib_is_virtual_base_of``                           ``202406L``
 454     ---------------------------------------------------------- -----------------
 455     ``__cpp_lib_is_within_lifetime``                           *unimplemented*
 456     ---------------------------------------------------------- -----------------
 457     ``__cpp_lib_linalg``                                       *unimplemented*
 458     ---------------------------------------------------------- -----------------
 459     ``__cpp_lib_mdspan``                                       ``202406L``
 460     ---------------------------------------------------------- -----------------
 461     ``__cpp_lib_optional_range_support``                       *unimplemented*
 462     ---------------------------------------------------------- -----------------
 463     ``__cpp_lib_out_ptr``                                      ``202311L``
 464     ---------------------------------------------------------- -----------------
 465     ``__cpp_lib_philox_engine``                                *unimplemented*
 466     ---------------------------------------------------------- -----------------
 467     ``__cpp_lib_ranges_concat``                                *unimplemented*
 468     ---------------------------------------------------------- -----------------
 469     ``__cpp_lib_ratio``                                        ``202306L``
 470     ---------------------------------------------------------- -----------------
 471     ``__cpp_lib_rcu``                                          *unimplemented*
 472     ---------------------------------------------------------- -----------------
 473     ``__cpp_lib_reference_wrapper``                            ``202403L``
 474     ---------------------------------------------------------- -----------------
 475     ``__cpp_lib_saturation_arithmetic``                        ``202311L``
 476     ---------------------------------------------------------- -----------------
 477     ``__cpp_lib_senders``                                      *unimplemented*
 478     ---------------------------------------------------------- -----------------
 479     ``__cpp_lib_smart_ptr_owner_equality``                     *unimplemented*
 480     ---------------------------------------------------------- -----------------
 481     ``__cpp_lib_span_at``                                      ``202311L``
 482     ---------------------------------------------------------- -----------------
 483     ``__cpp_lib_span_initializer_list``                        ``202311L``
 484     ---------------------------------------------------------- -----------------
 485     ``__cpp_lib_sstream_from_string_view``                     ``202306L``
 486     ---------------------------------------------------------- -----------------
 487     ``__cpp_lib_string_view``                                  ``202403L``
 488     ---------------------------------------------------------- -----------------
 489     ``__cpp_lib_submdspan``                                    *unimplemented*
 490     ---------------------------------------------------------- -----------------
 491     ``__cpp_lib_text_encoding``                                *unimplemented*
 492     ---------------------------------------------------------- -----------------
 493     ``__cpp_lib_to_chars``                                     *unimplemented*
 494     ---------------------------------------------------------- -----------------
 495     ``__cpp_lib_to_string``                                    *unimplemented*
 496     ---------------------------------------------------------- -----------------
 497     ``__cpp_lib_tuple_like``                                   *unimplemented*
 498     ---------------------------------------------------------- -----------------
 499     ``__cpp_lib_variant``                                      ``202306L``
 500     ========================================================== =================
 501