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_extern_fn
    36. 2.36. const_fn
    37. 2.37. const_fn_union
    38. 2.38. const_generics
    39. 2.39. const_in_array_repeat_expressions
    40. 2.40. const_mut_refs
    41. 2.41. const_panic
    42. 2.42. const_precise_live_drops
    43. 2.43. const_raw_ptr_deref
    44. 2.44. const_raw_ptr_to_usize_cast
    45. 2.45. const_trait_bound_opt_out
    46. 2.46. const_trait_impl
    47. 2.47. crate_visibility_modifier
    48. 2.48. custom_inner_attributes
    49. 2.49. custom_test_frameworks
    50. 2.50. decl_macro
    51. 2.51. default_type_parameter_fallback
    52. 2.52. doc_alias
    53. 2.53. doc_cfg
    54. 2.54. doc_keyword
    55. 2.55. doc_masked
    56. 2.56. dropck_eyepatch
    57. 2.57. exclusive_range_pattern
    58. 2.58. exhaustive_patterns
    59. 2.59. extern_types
    60. 2.60. external_doc
    61. 2.61. f16c_target_feature
    62. 2.62. ffi_const
    63. 2.63. ffi_pure
    64. 2.64. ffi_returns_twice
    65. 2.65. format_args_capture
    66. 2.66. fundamental
    67. 2.67. generators
    68. 2.68. generic_associated_types
    69. 2.69. half_open_range_patterns
    70. 2.70. hexagon_target_feature
    71. 2.71. impl_trait_in_bindings
    72. 2.72. in_band_lifetimes
    73. 2.73. infer_static_outlives_requirements
    74. 2.74. intrinsics
    75. 2.75. label_break_value
    76. 2.76. lang_items
    77. 2.77. lazy_normalization_consts
    78. 2.78. let_chains
    79. 2.79. link_args
    80. 2.80. link_cfg
    81. 2.81. link_llvm_intrinsics
    82. 2.82. linkage
    83. 2.83. lint_reasons
    84. 2.84. main
    85. 2.85. marker_trait_attr
    86. 2.86. member_constraints
    87. 2.87. min_specialization
    88. 2.88. mips_target_feature
    89. 2.89. mmx_target_feature
    90. 2.90. movbe_target_feature
    91. 2.91. move_ref_pattern
    92. 2.92. naked_functions
    93. 2.93. needs_panic_runtime
    94. 2.94. negative_impls
    95. 2.95. never_type
    96. 2.96. never_type_fallback
    97. 2.97. nll
    98. 2.98. no_core
    99. 2.99. no_niche
    100. 2.100. no_sanitize
    101. 2.101. non_ascii_idents
    102. 2.102. object_safe_for_dispatch
    103. 2.103. omit_gdb_pretty_printer_section
    104. 2.104. optimize_attribute
    105. 2.105. optin_builtin_traits
    106. 2.106. or_patterns
    107. 2.107. panic_runtime
    108. 2.108. platform_intrinsics
    109. 2.109. plugin
    110. 2.110. plugin_registrar
    111. 2.111. powerpc_target_feature
    112. 2.112. precise_pointer_size_matching
    113. 2.113. prelude_import
    114. 2.114. proc_macro_hygiene
    115. 2.115. profiler_runtime
    116. 2.116. raw_dylib
    117. 2.117. raw_ref_op
    118. 2.118. register_attr
    119. 2.119. register_tool
    120. 2.120. repr_simd
    121. 2.121. repr128
    122. 2.122. riscv_target_feature
    123. 2.123. rtm_target_feature
    124. 2.124. rustc_attrs
    125. 2.125. rustc_private
    126. 2.126. simd_ffi
    127. 2.127. specialization
    128. 2.128. sse4a_target_feature
    129. 2.129. staged_api
    130. 2.130. start
    131. 2.131. static_nobundle
    132. 2.132. stmt_expr_attributes
    133. 2.133. structural_match
    134. 2.134. target_feature_11
    135. 2.135. tbm_target_feature
    136. 2.136. test_2018_feature
    137. 2.137. thread_local
    138. 2.138. trait_alias
    139. 2.139. transparent_unions
    140. 2.140. trivial_bounds
    141. 2.141. try_blocks
    142. 2.142. type_alias_impl_trait
    143. 2.143. type_ascription
    144. 2.144. unboxed_closures
    145. 2.145. unsafe_block_in_unsafe_fn
    146. 2.146. unsized_locals
    147. 2.147. unsized_tuple_coercion
    148. 2.148. untagged_unions
    149. 2.149. unwind_attributes
    150. 2.150. 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. array_error_internals
    8. 3.8. array_value_iter
    9. 3.9. asm
    10. 3.10. assoc_char_consts
    11. 3.11. assoc_char_funcs
    12. 3.12. atomic_mut_ptr
    13. 3.13. backtrace
    14. 3.14. binary_heap_drain_sorted
    15. 3.15. binary_heap_into_iter_sorted
    16. 3.16. binary_heap_retain
    17. 3.17. bool_to_option
    18. 3.18. bound_cloned
    19. 3.19. box_into_boxed_slice
    20. 3.20. box_into_pin
    21. 3.21. box_into_raw_non_null
    22. 3.22. btree_drain_filter
    23. 3.23. bufreader_seek_relative
    24. 3.24. c_void_variant
    25. 3.25. can_vector
    26. 3.26. cell_leak
    27. 3.27. cell_update
    28. 3.28. cfg_accessible
    29. 3.29. char_error_internals
    30. 3.30. char_internals
    31. 3.31. clamp
    32. 3.32. cmp_min_max_by
    33. 3.33. coerce_unsized
    34. 3.34. concat_idents
    35. 3.35. const_alloc_layout
    36. 3.36. const_ascii_ctype_on_intrinsics
    37. 3.37. const_btree_new
    38. 3.38. const_caller_location
    39. 3.39. const_checked_int_methods
    40. 3.40. const_cstr_unchecked
    41. 3.41. const_cttz
    42. 3.42. const_discriminant
    43. 3.43. const_euclidean_int_methods
    44. 3.44. const_forget
    45. 3.45. const_generic_impls_guard
    46. 3.46. const_int_pow
    47. 3.47. const_int_sign
    48. 3.48. const_int_unchecked_arith
    49. 3.49. const_likely
    50. 3.50. const_nonnull_slice_from_raw_parts
    51. 3.51. const_nonzero_int_methods
    52. 3.52. const_overflowing_int_methods
    53. 3.53. const_pref_align_of
    54. 3.54. const_ptr_offset
    55. 3.55. const_ptr_offset_from
    56. 3.56. const_raw_ptr_comparison
    57. 3.57. const_result
    58. 3.58. const_saturating_int_methods
    59. 3.59. const_slice_from_raw_parts
    60. 3.60. const_slice_ptr_len
    61. 3.61. const_transmute
    62. 3.62. const_type_id
    63. 3.63. const_type_name
    64. 3.64. const_wrapping_int_methods
    65. 3.65. constctlz
    66. 3.66. container_error_extra
    67. 3.67. convert_float_to_int
    68. 3.68. core_intrinsics
    69. 3.69. core_panic
    70. 3.70. core_private_bignum
    71. 3.71. core_private_diy_float
    72. 3.72. cow_is_borrowed
    73. 3.73. cstring_from_vec_with_nul
    74. 3.74. deadline_api
    75. 3.75. debug_non_exhaustive
    76. 3.76. dec2flt
    77. 3.77. default_free_fn
    78. 3.78. deque_make_contiguous
    79. 3.79. derive_clone_copy
    80. 3.80. derive_eq
    81. 3.81. discriminant_kind
    82. 3.82. dispatch_from_dyn
    83. 3.83. div_duration
    84. 3.84. drain_filter
    85. 3.85. duration_constants
    86. 3.86. duration_zero
    87. 3.87. entry_insert
    88. 3.88. error_iter
    89. 3.89. error_type_id
    90. 3.90. exact_size_is_empty
    91. 3.91. extend_one
    92. 3.92. fd
    93. 3.93. fd_read
    94. 3.94. fixed_size_array
    95. 3.95. flt2dec
    96. 3.96. fmt_internals
    97. 3.97. fn_traits
    98. 3.98. foo
    99. 3.99. forget_unsized
    100. 3.100. format_args_nl
    101. 3.101. future_readiness_fns
    102. 3.102. gen_future
    103. 3.103. generator_trait
    104. 3.104. get_mut_unchecked
    105. 3.105. global_asm
    106. 3.106. hash_raw_entry
    107. 3.107. hash_set_entry
    108. 3.108. hashmap_internals
    109. 3.109. inner_deref
    110. 3.110. int_error_internals
    111. 3.111. int_error_matching
    112. 3.112. integer_atomics
    113. 3.113. internal_uninit_const
    114. 3.114. into_future
    115. 3.115. io_slice_advance
    116. 3.116. ip
    117. 3.117. is_sorted
    118. 3.118. iter_is_partitioned
    119. 3.119. iter_map_while
    120. 3.120. iter_order_by
    121. 3.121. iter_partition_in_place
    122. 3.122. iterator_fold_self
    123. 3.123. layout_for_ptr
    124. 3.124. liballoc_internals
    125. 3.125. libstd_io_internals
    126. 3.126. libstd_sys_internals
    127. 3.127. libstd_thread_internals
    128. 3.128. linked_list_cursors
    129. 3.129. linked_list_extras
    130. 3.130. linked_list_prepend
    131. 3.131. linked_list_remove
    132. 3.132. llvm_asm
    133. 3.133. log_syntax
    134. 3.134. map_entry_replace
    135. 3.135. map_first_last
    136. 3.136. maybe_uninit_extra
    137. 3.137. maybe_uninit_ref
    138. 3.138. maybe_uninit_slice
    139. 3.139. maybe_uninit_slice_assume_init
    140. 3.140. maybe_uninit_uninit_array
    141. 3.141. new_uninit
    142. 3.142. nonnull_slice_from_raw_parts
    143. 3.143. once_poison
    144. 3.144. option_expect_none
    145. 3.145. option_result_contains
    146. 3.146. option_unwrap_none
    147. 3.147. option_zip
    148. 3.148. or_insert_with_key
    149. 3.149. osstring_ascii
    150. 3.150. panic_abort
    151. 3.151. panic_info_message
    152. 3.152. panic_internals
    153. 3.153. panic_unwind
    154. 3.154. partition_point
    155. 3.155. pattern
    156. 3.156. peekable_next_if
    157. 3.157. poll_map
    158. 3.158. print_internals
    159. 3.159. proc_macro_def_site
    160. 3.160. proc_macro_diagnostic
    161. 3.161. proc_macro_internals
    162. 3.162. proc_macro_is_available
    163. 3.163. proc_macro_quote
    164. 3.164. proc_macro_raw_ident
    165. 3.165. proc_macro_span
    166. 3.166. process_exitcode_placeholder
    167. 3.167. process_internals
    168. 3.168. profiler_runtime_lib
    169. 3.169. ptr_internals
    170. 3.170. ptr_offset_from
    171. 3.171. ptr_wrapping_offset_from
    172. 3.172. range_is_empty
    173. 3.173. raw
    174. 3.174. raw_ref_macros
    175. 3.175. raw_vec_internals
    176. 3.176. rc_into_raw_non_null
    177. 3.177. read_initializer
    178. 3.178. receiver_trait
    179. 3.179. refcell_take
    180. 3.180. renamed_spin_loop
    181. 3.181. result_cloned
    182. 3.182. result_contains_err
    183. 3.183. result_copied
    184. 3.184. result_flattening
    185. 3.185. rt
    186. 3.186. seek_convenience
    187. 3.187. set_stdio
    188. 3.188. sgx_platform
    189. 3.189. shrink_to
    190. 3.190. slice_concat_ext
    191. 3.191. slice_concat_trait
    192. 3.192. slice_fill
    193. 3.193. slice_index_methods
    194. 3.194. slice_internals
    195. 3.195. slice_iter_mut_as_slice
    196. 3.196. slice_partition_at_index
    197. 3.197. slice_partition_dedup
    198. 3.198. slice_ptr_len
    199. 3.199. slice_ptr_range
    200. 3.200. slice_strip
    201. 3.201. sort_internals
    202. 3.202. split_inclusive
    203. 3.203. std_internals
    204. 3.204. stdsimd
    205. 3.205. step_trait
    206. 3.206. step_trait_ext
    207. 3.207. str_internals
    208. 3.208. tau_constant
    209. 3.209. termination_trait_lib
    210. 3.210. test
    211. 3.211. thread_id_value
    212. 3.212. thread_local_internals
    213. 3.213. thread_spawn_unchecked
    214. 3.214. tidy_test_never_used_anywhere_else
    215. 3.215. toowned_clone_into
    216. 3.216. total_cmp
    217. 3.217. trace_macros
    218. 3.218. trusted_len
    219. 3.219. try_find
    220. 3.220. try_reserve
    221. 3.221. try_trait
    222. 3.222. type_name_of_val
    223. 3.223. unchecked_math
    224. 3.224. unicode_internals
    225. 3.225. unsafe_cell_raw_get
    226. 3.226. unsize
    227. 3.227. unwrap_infallible
    228. 3.228. update_panic_count
    229. 3.229. variant_count
    230. 3.230. vec_into_raw_parts
    231. 3.231. vec_leak
    232. 3.232. vec_remove_item
    233. 3.233. vec_resize_default
    234. 3.234. wake_trait
    235. 3.235. wasi_ext
    236. 3.236. windows_by_handle
    237. 3.237. windows_c
    238. 3.238. windows_file_type_ext
    239. 3.239. windows_handle
    240. 3.240. windows_net
    241. 3.241. windows_stdio
    242. 3.242. with_options
    243. 3.243. wrapping_int_impl
    244. 3.244. wrapping_next_power_of_two
    245. 3.245. write_all_vectored

The Rust Unstable Book

Library Features