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