1. The Unstable Book
  2. Compiler flags
    1. branch_protection
    2. cf_protection
    3. codegen_backend
    4. codegen_options
    5. control_flow_guard
    6. coverage_options
    7. debug_info_for_profiling
    8. default_visibility
    9. direct_access_external_data
    10. dump_mono_stats
    11. dump_mono_stats_format
    12. dwarf_version
    13. dylib_lto
    14. embed_source
    15. emit_stack_sizes
    16. env_set
    17. export_executable_symbols
    18. extern_options
    19. external_clangrt
    20. fixed_x18
    21. fmt_debug
    22. function_return
    23. instrument_xray
    24. link_native_libraries
    25. linker_features
    26. lint_llvm_ir
    27. llvm_module_flag
    28. location_detail
    29. move_size_limit
    30. no_jump_tables
    31. no_parallel_llvm
    32. no_unique_section_names
    33. on_broken_pipe
    34. patchable_function_entry
    35. print_check_cfg
    36. profile_sample_use
    37. regparm
    38. remap_cwd_prefix
    39. remap_path_scope
    40. report_time
    41. sanitizer
    42. self_profile
    43. self_profile_events
    44. shell_argfiles
    45. small_data_threshold
    46. src_hash_algorithm
    47. temps_dir
    48. tiny_const_eval_limit
    49. tls_model
    50. ub_checks
    51. unsound_mir_opts
    52. verbose_asm
    53. virtual_function_elimination
    54. wasm_c_abi
  3. Language features
    1. aarch64_unstable_target_feature
    2. aarch64_ver_target_feature
    3. abi_avr_interrupt
    4. abi_c_cmse_nonsecure_call
    5. abi_msp430_interrupt
    6. abi_ptx
    7. abi_riscv_interrupt
    8. abi_unadjusted
    9. abi_vectorcall
    10. abi_x86_interrupt
    11. adt_const_params
    12. alloc_error_handler
    13. allocator_internals
    14. allow_internal_unsafe
    15. allow_internal_unstable
    16. anonymous_lifetime_in_impl_trait
    17. arbitrary_self_types
    18. arbitrary_self_types_pointers
    19. arm_target_feature
    20. asm_experimental_arch
    21. asm_experimental_reg
    22. asm_goto
    23. asm_goto_with_outputs
    24. asm_unwind
    25. associated_const_equality
    26. associated_type_defaults
    27. async_closure
    28. async_fn_track_caller
    29. async_for_loop
    30. auto_traits
    31. avx512_target_feature
    32. box_patterns
    33. bpf_target_feature
    34. builtin_syntax
    35. c_variadic
    36. cfg_boolean_literals
    37. cfg_overflow_checks
    38. cfg_relocation_model
    39. cfg_sanitize
    40. cfg_sanitizer_cfi
    41. cfg_target_compact
    42. cfg_target_has_atomic
    43. cfg_target_has_atomic_equal_alignment
    44. cfg_target_thread_local
    45. cfg_ub_checks
    46. cfg_version
    47. cfi_encoding
    48. closure_lifetime_binder
    49. closure_track_caller
    50. cmse_nonsecure_entry
    51. compiler_builtins
    52. const_async_blocks
    53. const_closures
    54. const_destruct
    55. const_for
    56. const_precise_live_drops
    57. const_trait_impl
    58. const_try
    59. coroutine_clone
    60. coroutines
    61. coverage_attribute
    62. csky_target_feature
    63. custom_inner_attributes
    64. custom_mir
    65. custom_test_frameworks
    66. decl_macro
    67. deprecated_safe
    68. deprecated_suggestion
    69. deref_patterns
    70. do_not_recommend
    71. doc_auto_cfg
    72. doc_cfg
    73. doc_cfg_hide
    74. doc_masked
    75. doc_notable_trait
    76. dropck_eyepatch
    77. dyn_compatible_for_dispatch
    78. dyn_star
    79. ermsb_target_feature
    80. exhaustive_patterns
    81. explicit_tail_calls
    82. extern_types
    83. f128
    84. f16
    85. ffi_const
    86. ffi_pure
    87. fmt_debug
    88. fn_align
    89. fn_delegation
    90. freeze_impls
    91. fundamental
    92. gen_blocks
    93. generic_arg_infer
    94. generic_assert
    95. generic_associated_types_extended
    96. generic_const_exprs
    97. generic_const_items
    98. global_registration
    99. half_open_range_patterns_in_slices
    100. hexagon_target_feature
    101. if_let_guard
    102. impl_trait_in_assoc_type
    103. impl_trait_in_fn_trait_return
    104. inherent_associated_types
    105. inline_const_pat
    106. intra_doc_pointers
    107. intrinsics
    108. lahfsahf_target_feature
    109. lang_items
    110. large_assignments
    111. lazy_type_alias
    112. let_chains
    113. lifetime_capture_rules_2024
    114. link_arg_attribute
    115. link_cfg
    116. link_llvm_intrinsics
    117. linkage
    118. loongarch_target_feature
    119. macro_metavar_expr
    120. macro_metavar_expr_concat
    121. marker_trait_attr
    122. min_generic_const_args
    123. min_specialization
    124. mips_target_feature
    125. more_maybe_bounds
    126. more_qualified_paths
    127. multiple_supertrait_upcastable
    128. must_not_suspend
    129. mut_ref
    130. naked_functions
    131. native_link_modifiers_as_needed
    132. needs_panic_runtime
    133. negative_bounds
    134. negative_impls
    135. never_patterns
    136. never_type
    137. never_type_fallback
    138. no_core
    139. no_sanitize
    140. non_exhaustive_omitted_patterns_lint
    141. non_lifetime_binders
    142. offset_of_enum
    143. offset_of_slice
    144. omit_gdb_pretty_printer_section
    145. optimize_attribute
    146. panic_runtime
    147. patchable_function_entry
    148. pattern_complexity
    149. pattern_types
    150. pin_ergonomics
    151. postfix_match
    152. powerpc_target_feature
    153. precise_capturing_in_traits
    154. prelude_import
    155. prfchw_target_feature
    156. proc_macro_hygiene
    157. profiler_runtime
    158. ref_pat_eat_one_layer_2024
    159. ref_pat_eat_one_layer_2024_structural
    160. register_tool
    161. repr_simd
    162. repr128
    163. return_type_notation
    164. riscv_target_feature
    165. rtm_target_feature
    166. rust_cold_cc
    167. rustc_allow_const_fn_unstable
    168. rustc_attrs
    169. rustc_private
    170. rustdoc_internals
    171. rustdoc_missing_doc_code_examples
    172. s390x_target_feature
    173. sha512_sm_x86
    174. simd_ffi
    175. sparc_target_feature
    176. specialization
    177. sse4a_target_feature
    178. staged_api
    179. start
    180. stmt_expr_attributes
    181. strict_provenance_lints
    182. string_deref_patterns
    183. structural_match
    184. target_feature_11
    185. tbm_target_feature
    186. test_unstable_lint
    187. thread_local
    188. trait_alias
    189. trait_upcasting
    190. transmute_generic_consts
    191. transparent_unions
    192. trivial_bounds
    193. try_blocks
    194. type_alias_impl_trait
    195. type_changing_struct_update
    196. unboxed_closures
    197. unqualified_local_imports
    198. unsafe_fields
    199. unsized_const_params
    200. unsized_fn_params
    201. unsized_locals
    202. unsized_tuple_coercion
    203. used_with_arg
    204. wasm_target_feature
    205. with_negative_coherence
    206. x86_amx_intrinsics
    207. xop_target_feature
    208. yeet_expr
  4. Library Features
    1. abort_unwind
    2. acceptfilter
    3. addr_parse_ascii
    4. alloc_error_hook
    5. alloc_internals
    6. alloc_layout_extra
    7. allocator_api
    8. anonymous_pipe
    9. array_chunks
    10. array_into_iter_constructors
    11. array_ptr_get
    12. array_repeat
    13. array_try_from_fn
    14. array_try_map
    15. array_windows
    16. as_array_of_cells
    17. ascii_char
    18. ascii_char_variants
    19. assert_matches
    20. async_drop
    21. async_fn_traits
    22. async_gen_internals
    23. async_iter_from_iter
    24. async_iterator
    25. atomic_from_mut
    26. autodiff
    27. backtrace_frames
    28. bigint_helper_methods
    29. binary_heap_drain_sorted
    30. binary_heap_into_iter_sorted
    31. bound_as_ref
    32. box_as_ptr
    33. box_into_boxed_slice
    34. box_into_inner
    35. box_uninit_write
    36. box_vec_non_null
    37. btree_cursors
    38. btree_entry_insert
    39. btree_extract_if
    40. btree_set_entry
    41. btreemap_alloc
    42. buf_read_has_data_left
    43. bufreader_peek
    44. build_hasher_default_const_new
    45. c_size_t
    46. c_str_module
    47. c_void_variant
    48. can_vector
    49. cell_leak
    50. cell_update
    51. cfg_accessible
    52. cfg_eval
    53. cfg_match
    54. char_internals
    55. clone_to_uninit
    56. cmp_minmax
    57. coerce_unsized
    58. concat_bytes
    59. concat_idents
    60. const_align_of_val
    61. const_align_of_val_raw
    62. const_alloc_error
    63. const_alloc_layout
    64. const_array_as_mut_slice
    65. const_array_each_ref
    66. const_black_box
    67. const_box
    68. const_btree_len
    69. const_cell
    70. const_char_classify
    71. const_collections_with_hasher
    72. const_copy_from_slice
    73. const_eq_ignore_ascii_case
    74. const_eval_select
    75. const_format_args
    76. const_heap
    77. const_is_char_boundary
    78. const_maybe_uninit_write
    79. const_mut_cursor
    80. const_nonnull_new
    81. const_ptr_sub_ptr
    82. const_range_bounds
    83. const_raw_ptr_comparison
    84. const_size_of_val
    85. const_size_of_val_raw
    86. const_slice_flatten
    87. const_slice_from_mut_ptr_range
    88. const_slice_from_ptr_range
    89. const_sockaddr_setters
    90. const_str_from_utf8
    91. const_str_split_at
    92. const_swap
    93. const_swap_nonoverlapping
    94. const_type_id
    95. const_type_name
    96. const_typed_swap
    97. const_vec_string_slice
    98. container_error_extra
    99. context_ext
    100. convert_float_to_int
    101. core_intrinsics
    102. core_io_borrowed_buf
    103. core_pattern_type
    104. core_pattern_types
    105. core_private_bignum
    106. core_private_diy_float
    107. coroutine_trait
    108. cow_is_borrowed
    109. cstr_bytes
    110. cstr_internals
    111. cursor_split
    112. deadline_api
    113. debug_closure_helpers
    114. dec2flt
    115. deref_pure_trait
    116. derive_clone_copy
    117. derive_coerce_pointee
    118. derive_const
    119. derive_eq
    120. dir_entry_ext2
    121. discriminant_kind
    122. dispatch_from_dyn
    123. downcast_unchecked
    124. drain_keep_rest
    125. duration_constants
    126. duration_constructors
    127. duration_millis_float
    128. duration_units
    129. edition_panic
    130. error_generic_member_access
    131. error_iter
    132. error_reporter
    133. error_type_id
    134. exact_size_is_empty
    135. exclusive_wrapper
    136. exit_status_error
    137. exitcode_exit_method
    138. extend_one
    139. extend_one_unchecked
    140. extract_if
    141. fd
    142. fd_read
    143. file_buffered
    144. file_lock
    145. float_gamma
    146. float_minimum_maximum
    147. float_next_up_down
    148. flt2dec
    149. fmt_helpers_for_derive
    150. fmt_internals
    151. fn_ptr_trait
    152. fn_traits
    153. forget_unsized
    154. format_args_nl
    155. freeze
    156. future_join
    157. gen_future
    158. generic_assert_internals
    159. get_many_mut
    160. get_many_mut_helpers
    161. get_mut_unchecked
    162. hash_extract_if
    163. hash_raw_entry
    164. hash_set_entry
    165. hasher_prefixfree_extras
    166. hashmap_internals
    167. hint_must_use
    168. inplace_iteration
    169. int_roundings
    170. integer_atomics
    171. integer_sign_cast
    172. internal_impls_macro
    173. internal_output_capture
    174. io_const_error
    175. io_const_error_internals
    176. io_error_inprogress
    177. io_error_more
    178. io_error_uncategorized
    179. io_slice_as_bytes
    180. ip
    181. ip_from
    182. is_ascii_octdigit
    183. is_loongarch_feature_detected
    184. is_riscv_feature_detected
    185. iter_advance_by
    186. iter_array_chunks
    187. iter_chain
    188. iter_collect_into
    189. iter_from_coroutine
    190. iter_intersperse
    191. iter_is_partitioned
    192. iter_map_windows
    193. iter_next_chunk
    194. iter_order_by
    195. iter_partition_in_place
    196. iterator_try_collect
    197. iterator_try_reduce
    198. junction_point
    199. layout_for_ptr
    200. lazy_cell_into_inner
    201. lazy_get
    202. legacy_receiver_trait
    203. liballoc_internals
    204. libstd_sys_internals
    205. linked_list_cursors
    206. linked_list_remove
    207. linked_list_retain
    208. linux_pidfd
    209. local_waker
    210. log_syntax
    211. map_many_mut
    212. map_try_insert
    213. mapped_lock_guards
    214. maybe_uninit_array_assume_init
    215. maybe_uninit_as_bytes
    216. maybe_uninit_fill
    217. maybe_uninit_slice
    218. maybe_uninit_uninit_array
    219. maybe_uninit_uninit_array_transpose
    220. maybe_uninit_write_slice
    221. mem_copy_fn
    222. mixed_integer_ops_unsigned_sub
    223. more_float_constants
    224. mpmc_channel
    225. new_range_api
    226. new_zeroed_alloc
    227. non_null_from_ref
    228. non_zero_count_ones
    229. nonzero_bitwise
    230. nonzero_from_mut
    231. nonzero_internals
    232. nonzero_ops
    233. noop_waker
    234. num_midpoint_signed
    235. numfmt
    236. once_cell_get_mut
    237. once_cell_try
    238. once_cell_try_insert
    239. once_wait
    240. one_sided_range
    241. option_array_transpose
    242. option_zip
    243. os_str_display
    244. os_str_slice
    245. os_string_pathbuf_leak
    246. os_string_truncate
    247. panic_abort
    248. panic_always_abort
    249. panic_backtrace_config
    250. panic_can_unwind
    251. panic_internals
    252. panic_payload_as_str
    253. panic_unwind
    254. panic_update_hook
    255. path_add_extension
    256. path_file_prefix
    257. pattern
    258. peer_credentials_unix_socket
    259. pin_coerce_unsized_trait
    260. pointer_is_aligned_to
    261. pointer_like_trait
    262. portable_simd
    263. prelude_2024
    264. print_internals
    265. proc_macro_def_site
    266. proc_macro_diagnostic
    267. proc_macro_expand
    268. proc_macro_internals
    269. proc_macro_quote
    270. proc_macro_span
    271. proc_macro_totokens
    272. proc_macro_tracked_env
    273. process_exitcode_internals
    274. process_internals
    275. profiler_runtime_lib
    276. ptr_alignment_type
    277. ptr_as_ref_unchecked
    278. ptr_as_uninit
    279. ptr_internals
    280. ptr_mask
    281. ptr_metadata
    282. ptr_sub_ptr
    283. pub_crate_should_not_need_unstable_attr
    284. random
    285. raw_os_error_ty
    286. raw_slice_split
    287. raw_vec_internals
    288. read_buf
    289. reentrant_lock
    290. restricted_std
    291. result_flattening
    292. round_char_boundary
    293. rt
    294. rustc_encodable_decodable
    295. rwlock_downgrade
    296. sealed
    297. seek_stream_len
    298. set_ptr_value
    299. setgroups
    300. sgx_platform
    301. sized_type_properties
    302. slice_as_array
    303. slice_as_chunks
    304. slice_concat_ext
    305. slice_concat_trait
    306. slice_from_ptr_range
    307. slice_index_methods
    308. slice_internals
    309. slice_iter_mut_as_mut_slice
    310. slice_partition_dedup
    311. slice_pattern
    312. slice_ptr_get
    313. slice_range
    314. slice_split_once
    315. slice_swap_unchecked
    316. slice_take
    317. solid_ext
    318. sort_floats
    319. split_array
    320. split_as_slice
    321. std_internals
    322. stdarch_arm_feature_detection
    323. stdarch_mips_feature_detection
    324. stdarch_powerpc_feature_detection
    325. stdio_makes_pipe
    326. step_trait
    327. str_as_str
    328. str_from_raw_parts
    329. str_from_utf16_endian
    330. str_internals
    331. str_lines_remainder
    332. str_split_inclusive_remainder
    333. str_split_remainder
    334. str_split_whitespace_remainder
    335. strict_overflow_ops
    336. strict_provenance_atomic_ptr
    337. string_extend_from_within
    338. string_from_utf8_lossy_owned
    339. string_remove_matches
    340. substr_range
    341. sync_unsafe_cell
    342. tcp_deferaccept
    343. tcp_linger
    344. tcp_quickack
    345. tcplistener_into_incoming
    346. test
    347. thin_box
    348. thread_id_value
    349. thread_local_internals
    350. thread_raw
    351. thread_sleep_until
    352. thread_spawn_hook
    353. trace_macros
    354. track_path
    355. transmutability
    356. trusted_fused
    357. trusted_len
    358. trusted_len_next_unchecked
    359. trusted_random_access
    360. trusted_step
    361. try_find
    362. try_reserve_kind
    363. try_trait_v2
    364. try_trait_v2_residual
    365. try_trait_v2_yeet
    366. try_with_capacity
    367. tuple_trait
    368. type_ascription
    369. ub_checks
    370. uefi_std
    371. unbounded_shifts
    372. unchecked_neg
    373. unchecked_shifts
    374. unicode_internals
    375. unique_rc_arc
    376. unix_file_vectored_at
    377. unix_set_mark
    378. unix_socket_ancillary_data
    379. unix_socket_peek
    380. unsafe_pin_internals
    381. unsigned_is_multiple_of
    382. unsigned_nonzero_div_ceil
    383. unsigned_signed_diff
    384. unsize
    385. unwrap_infallible
    386. update_panic_count
    387. utf16_extra
    388. variant_count
    389. vec_deque_iter_as_slices
    390. vec_into_raw_parts
    391. vec_pop_if
    392. vec_push_within_capacity
    393. vec_split_at_spare
    394. wasi_ext
    395. windows_by_handle
    396. windows_c
    397. windows_change_time
    398. windows_handle
    399. windows_net
    400. windows_process_exit_code_from
    401. windows_process_extensions_async_pipes
    402. windows_process_extensions_force_quotes
    403. windows_process_extensions_main_thread_handle
    404. windows_process_extensions_raw_attribute
    405. windows_process_extensions_show_window
    406. windows_stdio
    407. wrapping_int_impl
    408. wrapping_next_power_of_two
    409. write_all_vectored
    410. yeet_desugar_details