1. The Unstable Book
  2. Compiler flags
    1. autodiff
    2. branch_protection
    3. cf_protection
    4. codegen_backend
    5. codegen_options
    6. control_flow_guard
    7. coverage_options
    8. debug_info_for_profiling
    9. debug_info_type_line_numbers
    10. default_visibility
    11. direct_access_external_data
    12. dump_mono_stats
    13. dump_mono_stats_format
    14. dwarf_version
    15. dylib_lto
    16. embed_source
    17. emit_stack_sizes
    18. emscripten_wasm_eh
    19. env_set
    20. export_executable_symbols
    21. extern_options
    22. external_clangrt
    23. fixed_x18
    24. fmt_debug
    25. function_return
    26. instrument_xray
    27. link_native_libraries
    28. linker_features
    29. lint_llvm_ir
    30. llvm_module_flag
    31. location_detail
    32. min_function_alignment
    33. move_size_limit
    34. no_jump_tables
    35. no_parallel_llvm
    36. no_unique_section_names
    37. on_broken_pipe
    38. patchable_function_entry
    39. print_check_cfg
    40. profile_sample_use
    41. randomize_layout
    42. reg_struct_return
    43. regparm
    44. remap_cwd_prefix
    45. remap_path_scope
    46. report_time
    47. sanitizer
    48. self_profile
    49. self_profile_events
    50. shell_argfiles
    51. small_data_threshold
    52. src_hash_algorithm
    53. temps_dir
    54. tiny_const_eval_limit
    55. tls_model
    56. ub_checks
    57. unsound_mir_opts
    58. verbose_asm
    59. virtual_function_elimination
    60. 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_gpu_kernel
    6. abi_msp430_interrupt
    7. abi_ptx
    8. abi_riscv_interrupt
    9. abi_unadjusted
    10. abi_vectorcall
    11. abi_x86_interrupt
    12. adt_const_params
    13. alloc_error_handler
    14. allocator_internals
    15. allow_internal_unsafe
    16. allow_internal_unstable
    17. anonymous_lifetime_in_impl_trait
    18. arbitrary_self_types
    19. arbitrary_self_types_pointers
    20. arm_target_feature
    21. asm_experimental_arch
    22. asm_experimental_reg
    23. asm_goto
    24. asm_goto_with_outputs
    25. asm_unwind
    26. associated_const_equality
    27. associated_type_defaults
    28. async_fn_in_dyn_trait
    29. async_fn_track_caller
    30. async_for_loop
    31. async_trait_bounds
    32. auto_traits
    33. avx512_target_feature
    34. box_patterns
    35. bpf_target_feature
    36. builtin_syntax
    37. c_variadic
    38. cfg_boolean_literals
    39. cfg_contract_checks
    40. cfg_emscripten_wasm_eh
    41. cfg_overflow_checks
    42. cfg_relocation_model
    43. cfg_sanitize
    44. cfg_sanitizer_cfi
    45. cfg_target_compact
    46. cfg_target_has_atomic
    47. cfg_target_has_atomic_equal_alignment
    48. cfg_target_thread_local
    49. cfg_ub_checks
    50. cfg_version
    51. cfi_encoding
    52. closure_lifetime_binder
    53. closure_track_caller
    54. cmse_nonsecure_entry
    55. compiler_builtins
    56. const_async_blocks
    57. const_closures
    58. const_destruct
    59. const_for
    60. const_precise_live_drops
    61. const_trait_impl
    62. const_try
    63. contracts
    64. contracts_internals
    65. coroutine_clone
    66. coroutines
    67. coverage_attribute
    68. csky_target_feature
    69. custom_inner_attributes
    70. custom_mir
    71. custom_test_frameworks
    72. decl_macro
    73. default_field_values
    74. deprecated_safe
    75. deprecated_suggestion
    76. deref_patterns
    77. doc_auto_cfg
    78. doc_cfg
    79. doc_cfg_hide
    80. doc_masked
    81. doc_notable_trait
    82. dropck_eyepatch
    83. dyn_compatible_for_dispatch
    84. dyn_star
    85. ermsb_target_feature
    86. exhaustive_patterns
    87. explicit_tail_calls
    88. extern_types
    89. f128
    90. f16
    91. ffi_const
    92. ffi_pure
    93. fmt_debug
    94. fn_align
    95. fn_delegation
    96. freeze_impls
    97. fundamental
    98. gen_blocks
    99. generic_arg_infer
    100. generic_assert
    101. generic_const_exprs
    102. generic_const_items
    103. global_registration
    104. guard_patterns
    105. half_open_range_patterns_in_slices
    106. hexagon_target_feature
    107. if_let_guard
    108. impl_trait_in_assoc_type
    109. impl_trait_in_bindings
    110. impl_trait_in_fn_trait_return
    111. import_trait_associated_functions
    112. inherent_associated_types
    113. inline_const_pat
    114. intra_doc_pointers
    115. intrinsics
    116. keylocker_x86
    117. lahfsahf_target_feature
    118. lang_items
    119. large_assignments
    120. lazy_type_alias
    121. let_chains
    122. lifetime_capture_rules_2024
    123. link_arg_attribute
    124. link_cfg
    125. link_llvm_intrinsics
    126. linkage
    127. loongarch_target_feature
    128. m68k_target_feature
    129. macro_metavar_expr
    130. macro_metavar_expr_concat
    131. marker_trait_attr
    132. min_generic_const_args
    133. min_specialization
    134. mips_target_feature
    135. more_maybe_bounds
    136. more_qualified_paths
    137. multiple_supertrait_upcastable
    138. must_not_suspend
    139. mut_ref
    140. naked_functions
    141. native_link_modifiers_as_needed
    142. needs_panic_runtime
    143. negative_bounds
    144. negative_impls
    145. never_patterns
    146. never_type
    147. never_type_fallback
    148. new_range
    149. no_core
    150. no_sanitize
    151. non_exhaustive_omitted_patterns_lint
    152. non_lifetime_binders
    153. offset_of_enum
    154. offset_of_slice
    155. omit_gdb_pretty_printer_section
    156. optimize_attribute
    157. panic_runtime
    158. patchable_function_entry
    159. pattern_complexity
    160. pattern_types
    161. pin_ergonomics
    162. postfix_match
    163. powerpc_target_feature
    164. precise_capturing_in_traits
    165. prelude_import
    166. prfchw_target_feature
    167. proc_macro_hygiene
    168. profiler_runtime
    169. ref_pat_eat_one_layer_2024
    170. ref_pat_eat_one_layer_2024_structural
    171. register_tool
    172. repr_simd
    173. repr128
    174. return_type_notation
    175. riscv_target_feature
    176. rtm_target_feature
    177. rust_cold_cc
    178. rustc_allow_const_fn_unstable
    179. rustc_attrs
    180. rustc_private
    181. rustdoc_internals
    182. rustdoc_missing_doc_code_examples
    183. s390x_target_feature
    184. sha512_sm_x86
    185. simd_ffi
    186. sparc_target_feature
    187. specialization
    188. sse4a_target_feature
    189. staged_api
    190. stmt_expr_attributes
    191. strict_provenance_lints
    192. string_deref_patterns
    193. structural_match
    194. target_feature_11
    195. tbm_target_feature
    196. test_unstable_lint
    197. thread_local
    198. trait_alias
    199. transmute_generic_consts
    200. transparent_unions
    201. trivial_bounds
    202. try_blocks
    203. type_alias_impl_trait
    204. type_changing_struct_update
    205. unboxed_closures
    206. unqualified_local_imports
    207. unsafe_binders
    208. unsafe_fields
    209. unsized_const_params
    210. unsized_fn_params
    211. unsized_locals
    212. unsized_tuple_coercion
    213. used_with_arg
    214. wasm_target_feature
    215. with_negative_coherence
    216. x86_amx_intrinsics
    217. x87_target_feature
    218. xop_target_feature
    219. 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. atomic_try_update
    27. autodiff
    28. backtrace_frames
    29. bigint_helper_methods
    30. binary_heap_drain_sorted
    31. binary_heap_into_iter_sorted
    32. bound_as_ref
    33. box_as_ptr
    34. box_into_boxed_slice
    35. box_into_inner
    36. box_uninit_write
    37. box_vec_non_null
    38. breakpoint
    39. bstr
    40. bstr_internals
    41. btree_cursors
    42. btree_entry_insert
    43. btree_extract_if
    44. btree_set_entry
    45. btreemap_alloc
    46. buf_read_has_data_left
    47. bufreader_peek
    48. c_size_t
    49. c_str_module
    50. c_void_variant
    51. can_vector
    52. cell_leak
    53. cell_update
    54. cfg_accessible
    55. cfg_eval
    56. cfg_match
    57. char_internals
    58. clone_to_uninit
    59. cmp_minmax
    60. coerce_unsized
    61. cold_path
    62. concat_bytes
    63. concat_idents
    64. const_alloc_error
    65. const_array_as_mut_slice
    66. const_array_each_ref
    67. const_box
    68. const_btree_len
    69. const_carrying_mul_add
    70. const_cell
    71. const_char_classify
    72. const_copy_from_slice
    73. const_deref
    74. const_eq_ignore_ascii_case
    75. const_eval_select
    76. const_format_args
    77. const_heap
    78. const_is_char_boundary
    79. const_ops
    80. const_ptr_sub_ptr
    81. const_range_bounds
    82. const_raw_ptr_comparison
    83. const_slice_flatten
    84. const_slice_from_mut_ptr_range
    85. const_slice_from_ptr_range
    86. const_slice_reverse
    87. const_sockaddr_setters
    88. const_str_from_utf8
    89. const_str_split_at
    90. const_swap_nonoverlapping
    91. const_type_id
    92. const_type_name
    93. const_vec_string_slice
    94. container_error_extra
    95. context_ext
    96. convert_float_to_int
    97. core_intrinsics
    98. core_intrinsics_fallbacks
    99. core_io_borrowed_buf
    100. core_private_bignum
    101. core_private_diy_float
    102. coroutine_trait
    103. cow_is_borrowed
    104. cstr_bytes
    105. cstr_internals
    106. cursor_split
    107. deadline_api
    108. debug_closure_helpers
    109. dec2flt
    110. deref_pure_trait
    111. derive_clone_copy
    112. derive_coerce_pointee
    113. derive_const
    114. derive_eq
    115. dir_entry_ext2
    116. discriminant_kind
    117. disjoint_bitor
    118. dispatch_from_dyn
    119. downcast_unchecked
    120. drain_keep_rest
    121. duration_constants
    122. duration_constructors
    123. duration_millis_float
    124. duration_units
    125. edition_panic
    126. error_generic_member_access
    127. error_iter
    128. error_reporter
    129. error_type_id
    130. exact_size_is_empty
    131. exclusive_wrapper
    132. exit_status_error
    133. exitcode_exit_method
    134. extend_one
    135. extend_one_unchecked
    136. extract_if
    137. fd
    138. fd_read
    139. file_buffered
    140. file_lock
    141. float_gamma
    142. float_minimum_maximum
    143. flt2dec
    144. fmt_helpers_for_derive
    145. fmt_internals
    146. fn_ptr_trait
    147. fn_traits
    148. forget_unsized
    149. format_args_nl
    150. formatting_options
    151. freeze
    152. future_join
    153. gen_future
    154. generic_assert_internals
    155. get_many_mut
    156. get_many_mut_helpers
    157. get_mut_unchecked
    158. hash_extract_if
    159. hash_raw_entry
    160. hash_set_entry
    161. hasher_prefixfree_extras
    162. hashmap_internals
    163. hint_must_use
    164. inherent_str_constructors
    165. inplace_iteration
    166. int_from_ascii
    167. int_roundings
    168. integer_atomics
    169. integer_sign_cast
    170. internal_impls_macro
    171. internal_output_capture
    172. io_const_error
    173. io_const_error_internals
    174. io_error_inprogress
    175. io_error_more
    176. io_error_uncategorized
    177. io_slice_as_bytes
    178. ip
    179. ip_from
    180. is_ascii_octdigit
    181. is_loongarch_feature_detected
    182. is_riscv_feature_detected
    183. iter_advance_by
    184. iter_array_chunks
    185. iter_chain
    186. iter_collect_into
    187. iter_from_coroutine
    188. iter_intersperse
    189. iter_is_partitioned
    190. iter_map_windows
    191. iter_next_chunk
    192. iter_order_by
    193. iter_partition_in_place
    194. iterator_try_collect
    195. iterator_try_reduce
    196. junction_point
    197. layout_for_ptr
    198. lazy_cell_into_inner
    199. lazy_get
    200. legacy_receiver_trait
    201. liballoc_internals
    202. libstd_sys_internals
    203. likely_unlikely
    204. linked_list_cursors
    205. linked_list_remove
    206. linked_list_retain
    207. linux_pidfd
    208. local_waker
    209. lock_value_accessors
    210. log_syntax
    211. map_try_insert
    212. mapped_lock_guards
    213. maybe_uninit_array_assume_init
    214. maybe_uninit_as_bytes
    215. maybe_uninit_fill
    216. maybe_uninit_slice
    217. maybe_uninit_uninit_array
    218. maybe_uninit_uninit_array_transpose
    219. maybe_uninit_write_slice
    220. mem_copy_fn
    221. mixed_integer_ops_unsigned_sub
    222. more_float_constants
    223. mpmc_channel
    224. new_range_api
    225. new_zeroed_alloc
    226. non_null_from_ref
    227. non_zero_count_ones
    228. nonnull_provenance
    229. nonzero_bitwise
    230. nonzero_from_mut
    231. nonzero_internals
    232. nonzero_ops
    233. num_midpoint_signed
    234. numfmt
    235. once_cell_get_mut
    236. once_cell_try
    237. once_cell_try_insert
    238. one_sided_range
    239. option_array_transpose
    240. option_zip
    241. os_str_display
    242. os_str_slice
    243. os_string_pathbuf_leak
    244. os_string_truncate
    245. panic_abort
    246. panic_always_abort
    247. panic_backtrace_config
    248. panic_can_unwind
    249. panic_internals
    250. panic_payload_as_str
    251. panic_unwind
    252. panic_update_hook
    253. path_add_extension
    254. path_file_prefix
    255. pattern
    256. pattern_type_macro
    257. peer_credentials_unix_socket
    258. phantom_variance_markers
    259. pin_coerce_unsized_trait
    260. pointer_is_aligned_to
    261. pointer_like_trait
    262. portable_simd
    263. print_internals
    264. proc_macro_def_site
    265. proc_macro_diagnostic
    266. proc_macro_expand
    267. proc_macro_internals
    268. proc_macro_quote
    269. proc_macro_span
    270. proc_macro_totokens
    271. proc_macro_tracked_env
    272. process_exitcode_internals
    273. process_internals
    274. profiler_runtime_lib
    275. ptr_alignment_type
    276. ptr_as_ref_unchecked
    277. ptr_as_uninit
    278. ptr_internals
    279. ptr_mask
    280. ptr_metadata
    281. ptr_sub_ptr
    282. pub_crate_should_not_need_unstable_attr
    283. random
    284. raw_os_error_ty
    285. raw_slice_split
    286. raw_vec_internals
    287. read_buf
    288. reentrant_lock
    289. restricted_std
    290. result_flattening
    291. round_char_boundary
    292. rt
    293. rwlock_downgrade
    294. sealed
    295. seek_stream_len
    296. select_unpredictable
    297. set_ptr_value
    298. setgroups
    299. sgx_platform
    300. sized_type_properties
    301. slice_as_array
    302. slice_as_chunks
    303. slice_concat_ext
    304. slice_concat_trait
    305. slice_from_ptr_range
    306. slice_index_methods
    307. slice_internals
    308. slice_iter_mut_as_mut_slice
    309. slice_partition_dedup
    310. slice_pattern
    311. slice_ptr_get
    312. slice_range
    313. slice_split_once
    314. slice_swap_unchecked
    315. slice_take
    316. solid_ext
    317. sort_floats
    318. split_array
    319. split_as_slice
    320. std_internals
    321. stdarch_arm_feature_detection
    322. stdarch_mips_feature_detection
    323. stdarch_powerpc_feature_detection
    324. stdio_makes_pipe
    325. step_trait
    326. str_as_str
    327. str_from_raw_parts
    328. str_from_utf16_endian
    329. str_internals
    330. str_lines_remainder
    331. str_split_inclusive_remainder
    332. str_split_remainder
    333. str_split_whitespace_remainder
    334. strict_overflow_ops
    335. strict_provenance_atomic_ptr
    336. string_extend_from_within
    337. string_from_utf8_lossy_owned
    338. string_into_chars
    339. string_remove_matches
    340. substr_range
    341. sync_poison_mod
    342. sync_unsafe_cell
    343. tcp_deferaccept
    344. tcp_linger
    345. tcp_quickack
    346. tcplistener_into_incoming
    347. temporary_niche_types
    348. test
    349. thin_box
    350. thread_id_value
    351. thread_local_internals
    352. thread_raw
    353. thread_sleep_until
    354. thread_spawn_hook
    355. trace_macros
    356. track_path
    357. transmutability
    358. trusted_fused
    359. trusted_len
    360. trusted_len_next_unchecked
    361. trusted_random_access
    362. trusted_step
    363. try_find
    364. try_reserve_kind
    365. try_trait_v2
    366. try_trait_v2_residual
    367. try_trait_v2_yeet
    368. try_with_capacity
    369. tuple_trait
    370. type_ascription
    371. ub_checks
    372. uefi_std
    373. unbounded_shifts
    374. unchecked_neg
    375. unchecked_shifts
    376. unicode_internals
    377. unique_rc_arc
    378. unix_file_vectored_at
    379. unix_set_mark
    380. unix_socket_ancillary_data
    381. unix_socket_peek
    382. unsafe_cell_access
    383. unsafe_pin_internals
    384. unsigned_is_multiple_of
    385. unsigned_nonzero_div_ceil
    386. unsigned_signed_diff
    387. unsize
    388. unwrap_infallible
    389. update_panic_count
    390. utf16_extra
    391. variant_count
    392. vec_deque_iter_as_slices
    393. vec_deque_pop_if
    394. vec_into_raw_parts
    395. vec_push_within_capacity
    396. vec_split_at_spare
    397. wasi_ext
    398. windows_by_handle
    399. windows_c
    400. windows_change_time
    401. windows_handle
    402. windows_net
    403. windows_process_exit_code_from
    404. windows_process_extensions_async_pipes
    405. windows_process_extensions_force_quotes
    406. windows_process_extensions_main_thread_handle
    407. windows_process_extensions_raw_attribute
    408. windows_process_extensions_show_window
    409. windows_stdio
    410. wrapping_int_impl
    411. wrapping_next_power_of_two
    412. write_all_vectored
    413. yeet_desugar_details