1. The Unstable Book
  2. 1. Compiler flags
    1. 1.1. control_flow_guard
    2. 1.2. emit_stack_sizes
    3. 1.3. profile
    4. 1.4. report_time
    5. 1.5. sanitizer
    6. 1.6. self_profile
    7. 1.7. self_profile_events
    8. 1.8. src_hash_algorithm
    9. 1.9. strip
    10. 1.10. tls_model
  3. 2. Language features
    1. 2.1. aarch64_target_feature
    2. 2.2. abi_amdgpu_kernel
    3. 2.3. abi_avr_interrupt
    4. 2.4. abi_efiapi
    5. 2.5. abi_msp430_interrupt
    6. 2.6. abi_ptx
    7. 2.7. abi_thiscall
    8. 2.8. abi_unadjusted
    9. 2.9. abi_vectorcall
    10. 2.10. abi_x86_interrupt
    11. 2.11. adx_target_feature
    12. 2.12. alloc_error_handler
    13. 2.13. allocator_internals
    14. 2.14. allow_fail
    15. 2.15. allow_internal_unsafe
    16. 2.16. allow_internal_unstable
    17. 2.17. arbitrary_enum_discriminant
    18. 2.18. arbitrary_self_types
    19. 2.19. arm_target_feature
    20. 2.20. associated_type_bounds
    21. 2.21. associated_type_defaults
    22. 2.22. async_closure
    23. 2.23. avx512_target_feature
    24. 2.24. bindings_after_at
    25. 2.25. box_patterns
    26. 2.26. box_syntax
    27. 2.27. c_variadic
    28. 2.28. cfg_sanitize
    29. 2.29. cfg_target_has_atomic
    30. 2.30. cfg_target_thread_local
    31. 2.31. cfg_version
    32. 2.32. cmpxchg16b_target_feature
    33. 2.33. compiler_builtins
    34. 2.34. const_eval_limit
    35. 2.35. const_evaluatable_checked
    36. 2.36. const_extern_fn
    37. 2.37. const_fn
    38. 2.38. const_fn_transmute
    39. 2.39. const_fn_union
    40. 2.40. const_generics
    41. 2.41. const_in_array_repeat_expressions
    42. 2.42. const_mut_refs
    43. 2.43. const_panic
    44. 2.44. const_precise_live_drops
    45. 2.45. const_raw_ptr_deref
    46. 2.46. const_raw_ptr_to_usize_cast
    47. 2.47. const_trait_bound_opt_out
    48. 2.48. const_trait_impl
    49. 2.49. crate_visibility_modifier
    50. 2.50. custom_inner_attributes
    51. 2.51. custom_test_frameworks
    52. 2.52. decl_macro
    53. 2.53. default_type_parameter_fallback
    54. 2.54. doc_cfg
    55. 2.55. doc_keyword
    56. 2.56. doc_masked
    57. 2.57. doc_spotlight
    58. 2.58. dropck_eyepatch
    59. 2.59. exclusive_range_pattern
    60. 2.60. exhaustive_patterns
    61. 2.61. extern_types
    62. 2.62. external_doc
    63. 2.63. f16c_target_feature
    64. 2.64. ffi_const
    65. 2.65. ffi_pure
    66. 2.66. ffi_returns_twice
    67. 2.67. format_args_capture
    68. 2.68. fundamental
    69. 2.69. generators
    70. 2.70. generic_associated_types
    71. 2.71. half_open_range_patterns
    72. 2.72. hexagon_target_feature
    73. 2.73. if_let_guard
    74. 2.74. impl_trait_in_bindings
    75. 2.75. in_band_lifetimes
    76. 2.76. infer_static_outlives_requirements
    77. 2.77. intrinsics
    78. 2.78. label_break_value
    79. 2.79. lang_items
    80. 2.80. lazy_normalization_consts
    81. 2.81. let_chains
    82. 2.82. link_args
    83. 2.83. link_cfg
    84. 2.84. link_llvm_intrinsics
    85. 2.85. linkage
    86. 2.86. lint_reasons
    87. 2.87. main
    88. 2.88. marker_trait_attr
    89. 2.89. member_constraints
    90. 2.90. min_const_generics
    91. 2.91. min_specialization
    92. 2.92. mips_target_feature
    93. 2.93. mmx_target_feature
    94. 2.94. movbe_target_feature
    95. 2.95. move_ref_pattern
    96. 2.96. naked_functions
    97. 2.97. needs_panic_runtime
    98. 2.98. negative_impls
    99. 2.99. never_type
    100. 2.100. never_type_fallback
    101. 2.101. nll
    102. 2.102. no_core
    103. 2.103. no_niche
    104. 2.104. no_sanitize
    105. 2.105. non_ascii_idents
    106. 2.106. object_safe_for_dispatch
    107. 2.107. omit_gdb_pretty_printer_section
    108. 2.108. optimize_attribute
    109. 2.109. optin_builtin_traits
    110. 2.110. or_patterns
    111. 2.111. panic_runtime
    112. 2.112. platform_intrinsics
    113. 2.113. plugin
    114. 2.114. plugin_registrar
    115. 2.115. powerpc_target_feature
    116. 2.116. precise_pointer_size_matching
    117. 2.117. prelude_import
    118. 2.118. proc_macro_hygiene
    119. 2.119. profiler_runtime
    120. 2.120. raw_dylib
    121. 2.121. raw_ref_op
    122. 2.122. register_attr
    123. 2.123. register_tool
    124. 2.124. repr_simd
    125. 2.125. repr128
    126. 2.126. riscv_target_feature
    127. 2.127. rtm_target_feature
    128. 2.128. rustc_attrs
    129. 2.129. rustc_private
    130. 2.130. simd_ffi
    131. 2.131. specialization
    132. 2.132. sse4a_target_feature
    133. 2.133. staged_api
    134. 2.134. start
    135. 2.135. static_nobundle
    136. 2.136. stmt_expr_attributes
    137. 2.137. structural_match
    138. 2.138. target_feature_11
    139. 2.139. tbm_target_feature
    140. 2.140. test_2018_feature
    141. 2.141. thread_local
    142. 2.142. trait_alias
    143. 2.143. transparent_unions
    144. 2.144. trivial_bounds
    145. 2.145. try_blocks
    146. 2.146. type_alias_impl_trait
    147. 2.147. type_ascription
    148. 2.148. unboxed_closures
    149. 2.149. unsafe_block_in_unsafe_fn
    150. 2.150. unsized_locals
    151. 2.151. unsized_tuple_coercion
    152. 2.152. untagged_unions
    153. 2.153. unwind_attributes
    154. 2.154. wasm_target_feature
  4. 3. Library Features
    1. 3.1. alloc_error_hook
    2. 3.2. alloc_internals
    3. 3.3. alloc_layout_extra
    4. 3.4. alloc_prelude
    5. 3.5. allocator_api
    6. 3.6. arc_mutate_strong_count
    7. 3.7. arc_new_cyclic
    8. 3.8. array_chunks
    9. 3.9. array_error_internals
    10. 3.10. array_map
    11. 3.11. array_methods
    12. 3.12. array_value_iter
    13. 3.13. array_windows
    14. 3.14. asm
    15. 3.15. assoc_char_consts
    16. 3.16. assoc_char_funcs
    17. 3.17. atomic_from_mut
    18. 3.18. atomic_mut_ptr
    19. 3.19. backtrace
    20. 3.20. binary_heap_drain_sorted
    21. 3.21. binary_heap_into_iter_sorted
    22. 3.22. binary_heap_retain
    23. 3.23. bool_to_option
    24. 3.24. bound_cloned
    25. 3.25. box_into_boxed_slice
    26. 3.26. box_into_pin
    27. 3.27. btree_drain_filter
    28. 3.28. bufreader_seek_relative
    29. 3.29. c_void_variant
    30. 3.30. can_vector
    31. 3.31. cell_leak
    32. 3.32. cell_update
    33. 3.33. cfg_accessible
    34. 3.34. char_error_internals
    35. 3.35. char_internals
    36. 3.36. clamp
    37. 3.37. cmp_min_max_by
    38. 3.38. coerce_unsized
    39. 3.39. concat_idents
    40. 3.40. const_align_of_val
    41. 3.41. const_alloc_layout
    42. 3.42. const_btree_new
    43. 3.43. const_caller_location
    44. 3.44. const_checked_int_methods
    45. 3.45. const_cstr_unchecked
    46. 3.46. const_cttz
    47. 3.47. const_discriminant
    48. 3.48. const_euclidean_int_methods
    49. 3.49. const_float_bits_conv
    50. 3.50. const_float_classify
    51. 3.51. const_int_pow
    52. 3.52. const_int_unchecked_arith
    53. 3.53. const_ipv4
    54. 3.54. const_ipv6
    55. 3.55. const_likely
    56. 3.56. const_maybe_uninit_as_ptr
    57. 3.57. const_nonnull_slice_from_raw_parts
    58. 3.58. const_option
    59. 3.59. const_overflowing_int_methods
    60. 3.60. const_pref_align_of
    61. 3.61. const_ptr_is_null
    62. 3.62. const_ptr_offset
    63. 3.63. const_ptr_offset_from
    64. 3.64. const_raw_ptr_comparison
    65. 3.65. const_result
    66. 3.66. const_size_of_val
    67. 3.67. const_slice_from_raw_parts
    68. 3.68. const_slice_ptr_len
    69. 3.69. const_str_from_utf8_unchecked
    70. 3.70. const_type_name
    71. 3.71. const_unreachable_unchecked
    72. 3.72. const_wrapping_int_methods
    73. 3.73. constctlz
    74. 3.74. container_error_extra
    75. 3.75. control_flow_enum
    76. 3.76. convert_float_to_int
    77. 3.77. core_intrinsics
    78. 3.78. core_panic
    79. 3.79. core_private_bignum
    80. 3.80. core_private_diy_float
    81. 3.81. cow_is_borrowed
    82. 3.82. cstring_from_vec_with_nul
    83. 3.83. deadline_api
    84. 3.84. debug_non_exhaustive
    85. 3.85. dec2flt
    86. 3.86. default_free_fn
    87. 3.87. deque_range
    88. 3.88. derive_clone_copy
    89. 3.89. derive_eq
    90. 3.90. discriminant_kind
    91. 3.91. dispatch_from_dyn
    92. 3.92. div_duration
    93. 3.93. drain_filter
    94. 3.94. duration_constants
    95. 3.95. duration_consts_2
    96. 3.96. duration_saturating_ops
    97. 3.97. duration_zero
    98. 3.98. entry_insert
    99. 3.99. error_iter
    100. 3.100. error_type_id
    101. 3.101. exact_size_is_empty
    102. 3.102. extend_one
    103. 3.103. fd
    104. 3.104. fd_read
    105. 3.105. fixed_size_array
    106. 3.106. flt2dec
    107. 3.107. fmt_as_str
    108. 3.108. fmt_internals
    109. 3.109. fn_traits
    110. 3.110. foo
    111. 3.111. forget_unsized
    112. 3.112. format_args_nl
    113. 3.113. future_poll_fn
    114. 3.114. gen_future
    115. 3.115. generator_trait
    116. 3.116. get_mut_unchecked
    117. 3.117. global_asm
    118. 3.118. hash_drain_filter
    119. 3.119. hash_raw_entry
    120. 3.120. hash_set_entry
    121. 3.121. hashmap_internals
    122. 3.122. inplace_iteration
    123. 3.123. int_bits_const
    124. 3.124. int_error_internals
    125. 3.125. int_error_matching
    126. 3.126. integer_atomics
    127. 3.127. into_future
    128. 3.128. io_slice_advance
    129. 3.129. ip
    130. 3.130. is_sorted
    131. 3.131. iter_is_partitioned
    132. 3.132. iter_map_while
    133. 3.133. iter_order_by
    134. 3.134. iter_partition_in_place
    135. 3.135. iterator_fold_self
    136. 3.136. layout_for_ptr
    137. 3.137. liballoc_internals
    138. 3.138. libstd_io_internals
    139. 3.139. libstd_sys_internals
    140. 3.140. libstd_thread_internals
    141. 3.141. linked_list_cursors
    142. 3.142. linked_list_extras
    143. 3.143. linked_list_prepend
    144. 3.144. linked_list_remove
    145. 3.145. llvm_asm
    146. 3.146. log_syntax
    147. 3.147. map_entry_replace
    148. 3.148. map_first_last
    149. 3.149. map_into_keys_values
    150. 3.150. maybe_uninit_extra
    151. 3.151. maybe_uninit_ref
    152. 3.152. maybe_uninit_slice
    153. 3.153. maybe_uninit_uninit_array
    154. 3.154. new_uninit
    155. 3.155. nonnull_slice_from_raw_parts
    156. 3.156. once_cell
    157. 3.157. once_poison
    158. 3.158. option_expect_none
    159. 3.159. option_result_contains
    160. 3.160. option_unwrap_none
    161. 3.161. option_zip
    162. 3.162. or_insert_with_key
    163. 3.163. osstring_ascii
    164. 3.164. panic_abort
    165. 3.165. panic_info_message
    166. 3.166. panic_internals
    167. 3.167. panic_unwind
    168. 3.168. partition_point
    169. 3.169. pattern
    170. 3.170. peekable_next_if
    171. 3.171. peer_credentials_unix_socket
    172. 3.172. poll_map
    173. 3.173. print_internals
    174. 3.174. proc_macro_def_site
    175. 3.175. proc_macro_diagnostic
    176. 3.176. proc_macro_internals
    177. 3.177. proc_macro_is_available
    178. 3.178. proc_macro_quote
    179. 3.179. proc_macro_span
    180. 3.180. proc_macro_tracked_env
    181. 3.181. process_exitcode_placeholder
    182. 3.182. process_internals
    183. 3.183. profiler_runtime_lib
    184. 3.184. ptr_as_uninit
    185. 3.185. ptr_internals
    186. 3.186. raw
    187. 3.187. raw_ref_macros
    188. 3.188. raw_vec_internals
    189. 3.189. read_initializer
    190. 3.190. ready_macro
    191. 3.191. receiver_trait
    192. 3.192. refcell_take
    193. 3.193. renamed_spin_loop
    194. 3.194. result_cloned
    195. 3.195. result_contains_err
    196. 3.196. result_copied
    197. 3.197. result_flattening
    198. 3.198. rt
    199. 3.199. seek_convenience
    200. 3.200. set_ptr_value
    201. 3.201. set_stdio
    202. 3.202. sgx_platform
    203. 3.203. shrink_to
    204. 3.204. slice_check_range
    205. 3.205. slice_concat_ext
    206. 3.206. slice_concat_trait
    207. 3.207. slice_fill
    208. 3.208. slice_index_methods
    209. 3.209. slice_internals
    210. 3.210. slice_iter_mut_as_slice
    211. 3.211. slice_partition_at_index
    212. 3.212. slice_partition_dedup
    213. 3.213. slice_ptr_get
    214. 3.214. slice_ptr_len
    215. 3.215. slice_ptr_range
    216. 3.216. slice_split_at_unchecked
    217. 3.217. slice_strip
    218. 3.218. sort_internals
    219. 3.219. split_inclusive
    220. 3.220. std_internals
    221. 3.221. stdsimd
    222. 3.222. step_trait
    223. 3.223. step_trait_ext
    224. 3.224. str_internals
    225. 3.225. str_split_once
    226. 3.226. string_drain_as_str
    227. 3.227. termination_trait_lib
    228. 3.228. test
    229. 3.229. thread_id_value
    230. 3.230. thread_local_internals
    231. 3.231. thread_spawn_unchecked
    232. 3.232. toowned_clone_into
    233. 3.233. total_cmp
    234. 3.234. trace_macros
    235. 3.235. trusted_len
    236. 3.236. trusted_random_access
    237. 3.237. try_find
    238. 3.238. try_reserve
    239. 3.239. try_trait
    240. 3.240. type_name_of_val
    241. 3.241. unchecked_math
    242. 3.242. unicode_internals
    243. 3.243. unix_socket_peek
    244. 3.244. unsafe_cell_raw_get
    245. 3.245. unsigned_abs
    246. 3.246. unsize
    247. 3.247. unwrap_infallible
    248. 3.248. update_panic_count
    249. 3.249. variant_count
    250. 3.250. vec_into_raw_parts
    251. 3.251. vec_remove_item
    252. 3.252. vec_resize_default
    253. 3.253. vec_spare_capacity
    254. 3.254. wake_trait
    255. 3.255. wasi_ext
    256. 3.256. windows_by_handle
    257. 3.257. windows_c
    258. 3.258. windows_file_type_ext
    259. 3.259. windows_handle
    260. 3.260. windows_net
    261. 3.261. windows_stdio
    262. 3.262. with_options
    263. 3.263. wrapping_int_impl
    264. 3.264. wrapping_next_power_of_two
    265. 3.265. write_all_vectored

The Rust Unstable Book

Library Features