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. debug_info_type_line_numbers
    9. default_visibility
    10. direct_access_external_data
    11. dump_mono_stats
    12. dump_mono_stats_format
    13. dwarf_version
    14. dylib_lto
    15. embed_source
    16. emit_stack_sizes
    17. env_set
    18. export_executable_symbols
    19. extern_options
    20. external_clangrt
    21. fixed_x18
    22. fmt_debug
    23. function_return
    24. instrument_xray
    25. link_native_libraries
    26. linker_features
    27. lint_llvm_ir
    28. llvm_module_flag
    29. location_detail
    30. move_size_limit
    31. no_jump_tables
    32. no_parallel_llvm
    33. no_unique_section_names
    34. on_broken_pipe
    35. patchable_function_entry
    36. print_check_cfg
    37. profile_sample_use
    38. randomize_layout
    39. reg_struct_return
    40. regparm
    41. remap_cwd_prefix
    42. remap_path_scope
    43. report_time
    44. sanitizer
    45. self_profile
    46. self_profile_events
    47. shell_argfiles
    48. small_data_threshold
    49. src_hash_algorithm
    50. temps_dir
    51. tiny_const_eval_limit
    52. tls_model
    53. ub_checks
    54. unsound_mir_opts
    55. verbose_asm
    56. virtual_function_elimination
    57. 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. async_trait_bounds
    31. auto_traits
    32. avx512_target_feature
    33. box_patterns
    34. bpf_target_feature
    35. builtin_syntax
    36. c_variadic
    37. cfg_boolean_literals
    38. cfg_overflow_checks
    39. cfg_relocation_model
    40. cfg_sanitize
    41. cfg_sanitizer_cfi
    42. cfg_target_compact
    43. cfg_target_has_atomic
    44. cfg_target_has_atomic_equal_alignment
    45. cfg_target_thread_local
    46. cfg_ub_checks
    47. cfg_version
    48. cfi_encoding
    49. closure_lifetime_binder
    50. closure_track_caller
    51. cmse_nonsecure_entry
    52. compiler_builtins
    53. const_async_blocks
    54. const_closures
    55. const_destruct
    56. const_for
    57. const_precise_live_drops
    58. const_trait_impl
    59. const_try
    60. coroutine_clone
    61. coroutines
    62. coverage_attribute
    63. csky_target_feature
    64. custom_inner_attributes
    65. custom_mir
    66. custom_test_frameworks
    67. decl_macro
    68. deprecated_safe
    69. deprecated_suggestion
    70. deref_patterns
    71. do_not_recommend
    72. doc_auto_cfg
    73. doc_cfg
    74. doc_cfg_hide
    75. doc_masked
    76. doc_notable_trait
    77. dropck_eyepatch
    78. dyn_compatible_for_dispatch
    79. dyn_star
    80. ermsb_target_feature
    81. exhaustive_patterns
    82. explicit_tail_calls
    83. extern_types
    84. f128
    85. f16
    86. ffi_const
    87. ffi_pure
    88. fmt_debug
    89. fn_align
    90. fn_delegation
    91. freeze_impls
    92. fundamental
    93. gen_blocks
    94. generic_arg_infer
    95. generic_assert
    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. breakpoint
    38. btree_cursors
    39. btree_entry_insert
    40. btree_extract_if
    41. btree_set_entry
    42. btreemap_alloc
    43. buf_read_has_data_left
    44. bufreader_peek
    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_alloc_error
    61. const_alloc_layout
    62. const_array_as_mut_slice
    63. const_array_each_ref
    64. const_black_box
    65. const_box
    66. const_btree_len
    67. const_cell
    68. const_char_classify
    69. const_copy_from_slice
    70. const_eq_ignore_ascii_case
    71. const_eval_select
    72. const_format_args
    73. const_heap
    74. const_is_char_boundary
    75. const_mut_cursor
    76. const_nonnull_new
    77. const_ptr_sub_ptr
    78. const_range_bounds
    79. const_raw_ptr_comparison
    80. const_slice_flatten
    81. const_slice_from_mut_ptr_range
    82. const_slice_from_ptr_range
    83. const_sockaddr_setters
    84. const_str_from_utf8
    85. const_str_split_at
    86. const_swap
    87. const_swap_nonoverlapping
    88. const_type_id
    89. const_type_name
    90. const_typed_swap
    91. const_vec_string_slice
    92. container_error_extra
    93. context_ext
    94. convert_float_to_int
    95. core_intrinsics
    96. core_io_borrowed_buf
    97. core_private_bignum
    98. core_private_diy_float
    99. coroutine_trait
    100. cow_is_borrowed
    101. cstr_bytes
    102. cstr_internals
    103. cursor_split
    104. deadline_api
    105. debug_closure_helpers
    106. dec2flt
    107. deref_pure_trait
    108. derive_clone_copy
    109. derive_coerce_pointee
    110. derive_const
    111. derive_eq
    112. dir_entry_ext2
    113. discriminant_kind
    114. dispatch_from_dyn
    115. downcast_unchecked
    116. drain_keep_rest
    117. duration_constants
    118. duration_constructors
    119. duration_millis_float
    120. duration_units
    121. edition_panic
    122. error_generic_member_access
    123. error_iter
    124. error_reporter
    125. error_type_id
    126. exact_size_is_empty
    127. exclusive_wrapper
    128. exit_status_error
    129. exitcode_exit_method
    130. extend_one
    131. extend_one_unchecked
    132. extract_if
    133. fd
    134. fd_read
    135. file_buffered
    136. file_lock
    137. float_gamma
    138. float_minimum_maximum
    139. float_next_up_down
    140. flt2dec
    141. fmt_helpers_for_derive
    142. fmt_internals
    143. fn_ptr_trait
    144. fn_traits
    145. forget_unsized
    146. format_args_nl
    147. freeze
    148. future_join
    149. gen_future
    150. generic_assert_internals
    151. get_many_mut
    152. get_many_mut_helpers
    153. get_mut_unchecked
    154. hash_extract_if
    155. hash_raw_entry
    156. hash_set_entry
    157. hasher_prefixfree_extras
    158. hashmap_internals
    159. hint_must_use
    160. inplace_iteration
    161. int_roundings
    162. integer_atomics
    163. integer_sign_cast
    164. internal_impls_macro
    165. internal_output_capture
    166. io_const_error
    167. io_const_error_internals
    168. io_error_inprogress
    169. io_error_more
    170. io_error_uncategorized
    171. io_slice_as_bytes
    172. ip
    173. ip_from
    174. is_ascii_octdigit
    175. is_loongarch_feature_detected
    176. is_riscv_feature_detected
    177. iter_advance_by
    178. iter_array_chunks
    179. iter_chain
    180. iter_collect_into
    181. iter_from_coroutine
    182. iter_intersperse
    183. iter_is_partitioned
    184. iter_map_windows
    185. iter_next_chunk
    186. iter_order_by
    187. iter_partition_in_place
    188. iterator_try_collect
    189. iterator_try_reduce
    190. junction_point
    191. layout_for_ptr
    192. lazy_cell_into_inner
    193. lazy_get
    194. legacy_receiver_trait
    195. liballoc_internals
    196. libstd_sys_internals
    197. linked_list_cursors
    198. linked_list_remove
    199. linked_list_retain
    200. linux_pidfd
    201. local_waker
    202. log_syntax
    203. map_many_mut
    204. map_try_insert
    205. mapped_lock_guards
    206. maybe_uninit_array_assume_init
    207. maybe_uninit_as_bytes
    208. maybe_uninit_fill
    209. maybe_uninit_slice
    210. maybe_uninit_uninit_array
    211. maybe_uninit_uninit_array_transpose
    212. maybe_uninit_write_slice
    213. mem_copy_fn
    214. mixed_integer_ops_unsigned_sub
    215. more_float_constants
    216. mpmc_channel
    217. new_range_api
    218. new_zeroed_alloc
    219. non_null_from_ref
    220. non_zero_count_ones
    221. nonzero_bitwise
    222. nonzero_from_mut
    223. nonzero_internals
    224. nonzero_ops
    225. num_midpoint_signed
    226. numfmt
    227. once_cell_get_mut
    228. once_cell_try
    229. once_cell_try_insert
    230. once_wait
    231. one_sided_range
    232. option_array_transpose
    233. option_zip
    234. os_str_display
    235. os_str_slice
    236. os_string_pathbuf_leak
    237. os_string_truncate
    238. panic_abort
    239. panic_always_abort
    240. panic_backtrace_config
    241. panic_can_unwind
    242. panic_internals
    243. panic_payload_as_str
    244. panic_unwind
    245. panic_update_hook
    246. path_add_extension
    247. path_file_prefix
    248. pattern
    249. pattern_type_macro
    250. peer_credentials_unix_socket
    251. pin_coerce_unsized_trait
    252. pointer_is_aligned_to
    253. pointer_like_trait
    254. portable_simd
    255. prelude_2024
    256. print_internals
    257. proc_macro_def_site
    258. proc_macro_diagnostic
    259. proc_macro_expand
    260. proc_macro_internals
    261. proc_macro_quote
    262. proc_macro_span
    263. proc_macro_totokens
    264. proc_macro_tracked_env
    265. process_exitcode_internals
    266. process_internals
    267. profiler_runtime_lib
    268. ptr_alignment_type
    269. ptr_as_ref_unchecked
    270. ptr_as_uninit
    271. ptr_internals
    272. ptr_mask
    273. ptr_metadata
    274. ptr_sub_ptr
    275. pub_crate_should_not_need_unstable_attr
    276. random
    277. raw_os_error_ty
    278. raw_slice_split
    279. raw_vec_internals
    280. read_buf
    281. reentrant_lock
    282. restricted_std
    283. result_flattening
    284. round_char_boundary
    285. rt
    286. rustc_encodable_decodable
    287. rwlock_downgrade
    288. sealed
    289. seek_stream_len
    290. set_ptr_value
    291. setgroups
    292. sgx_platform
    293. sized_type_properties
    294. slice_as_array
    295. slice_as_chunks
    296. slice_concat_ext
    297. slice_concat_trait
    298. slice_from_ptr_range
    299. slice_index_methods
    300. slice_internals
    301. slice_iter_mut_as_mut_slice
    302. slice_partition_dedup
    303. slice_pattern
    304. slice_ptr_get
    305. slice_range
    306. slice_split_once
    307. slice_swap_unchecked
    308. slice_take
    309. solid_ext
    310. sort_floats
    311. split_array
    312. split_as_slice
    313. std_internals
    314. stdarch_arm_feature_detection
    315. stdarch_mips_feature_detection
    316. stdarch_powerpc_feature_detection
    317. stdio_makes_pipe
    318. step_trait
    319. str_as_str
    320. str_from_raw_parts
    321. str_from_utf16_endian
    322. str_internals
    323. str_lines_remainder
    324. str_split_inclusive_remainder
    325. str_split_remainder
    326. str_split_whitespace_remainder
    327. strict_overflow_ops
    328. strict_provenance_atomic_ptr
    329. string_extend_from_within
    330. string_from_utf8_lossy_owned
    331. string_remove_matches
    332. substr_range
    333. sync_unsafe_cell
    334. tcp_deferaccept
    335. tcp_linger
    336. tcp_quickack
    337. tcplistener_into_incoming
    338. test
    339. thin_box
    340. thread_id_value
    341. thread_local_internals
    342. thread_raw
    343. thread_sleep_until
    344. thread_spawn_hook
    345. trace_macros
    346. track_path
    347. transmutability
    348. trusted_fused
    349. trusted_len
    350. trusted_len_next_unchecked
    351. trusted_random_access
    352. trusted_step
    353. try_find
    354. try_reserve_kind
    355. try_trait_v2
    356. try_trait_v2_residual
    357. try_trait_v2_yeet
    358. try_with_capacity
    359. tuple_trait
    360. type_ascription
    361. ub_checks
    362. uefi_std
    363. unbounded_shifts
    364. unchecked_neg
    365. unchecked_shifts
    366. unicode_internals
    367. unique_rc_arc
    368. unix_file_vectored_at
    369. unix_set_mark
    370. unix_socket_ancillary_data
    371. unix_socket_peek
    372. unsafe_pin_internals
    373. unsigned_is_multiple_of
    374. unsigned_nonzero_div_ceil
    375. unsigned_signed_diff
    376. unsize
    377. unwrap_infallible
    378. update_panic_count
    379. utf16_extra
    380. variant_count
    381. vec_deque_iter_as_slices
    382. vec_into_raw_parts
    383. vec_pop_if
    384. vec_push_within_capacity
    385. vec_split_at_spare
    386. wasi_ext
    387. windows_by_handle
    388. windows_c
    389. windows_change_time
    390. windows_handle
    391. windows_net
    392. windows_process_exit_code_from
    393. windows_process_extensions_async_pipes
    394. windows_process_extensions_force_quotes
    395. windows_process_extensions_main_thread_handle
    396. windows_process_extensions_raw_attribute
    397. windows_process_extensions_show_window
    398. windows_stdio
    399. wrapping_int_impl
    400. wrapping_next_power_of_two
    401. write_all_vectored
    402. yeet_desugar_details