core/
lib.rs

1//! # The Rust Core Library
2//!
3//! The Rust Core Library is the dependency-free[^free] foundation of [The
4//! Rust Standard Library](../std/index.html). It is the portable glue
5//! between the language and its libraries, defining the intrinsic and
6//! primitive building blocks of all Rust code. It links to no
7//! upstream libraries, no system libraries, and no libc.
8//!
9//! [^free]: Strictly speaking, there are some symbols which are needed but
10//!          they aren't always necessary.
11//!
12//! The core library is *minimal*: it isn't even aware of heap allocation,
13//! nor does it provide concurrency or I/O. These things require
14//! platform integration, and this library is platform-agnostic.
15//!
16//! # How to use the core library
17//!
18//! Please note that all of these details are currently not considered stable.
19//!
20// FIXME: Fill me in with more detail when the interface settles
21//! This library is built on the assumption of a few existing symbols:
22//!
23//! * `memcpy`, `memmove`, `memset`, `memcmp`, `bcmp`, `strlen` - These are core memory routines
24//!   which are generated by Rust codegen backends. Additionally, this library can make explicit
25//!   calls to `strlen`. Their signatures are the same as found in C, but there are extra
26//!   assumptions about their semantics: For `memcpy`, `memmove`, `memset`, `memcmp`, and `bcmp`, if
27//!   the `n` parameter is 0, the function is assumed to not be UB, even if the pointers are NULL or
28//!   dangling. (Note that making extra assumptions about these functions is common among compilers:
29//!   [clang](https://reviews.llvm.org/D86993) and [GCC](https://gcc.gnu.org/onlinedocs/gcc/Standards.html#C-Language) do the same.)
30//!   These functions are often provided by the system libc, but can also be provided by the
31//!   [compiler-builtins crate](https://crates.io/crates/compiler_builtins).
32//!   Note that the library does not guarantee that it will always make these assumptions, so Rust
33//!   user code directly calling the C functions should follow the C specification! The advice for
34//!   Rust user code is to call the functions provided by this library instead (such as
35//!   `ptr::copy`).
36//!
37//! * Panic handler - This function takes one argument, a `&panic::PanicInfo`. It is up to consumers of this core
38//!   library to define this panic function; it is only required to never
39//!   return. You should mark your implementation using `#[panic_handler]`.
40//!
41//! * `rust_eh_personality` - is used by the failure mechanisms of the
42//!    compiler. This is often mapped to GCC's personality function, but crates
43//!    which do not trigger a panic can be assured that this function is never
44//!    called. The `lang` attribute is called `eh_personality`.
45
46#![stable(feature = "core", since = "1.6.0")]
47#![doc(
48    html_playground_url = "https://play.rust-lang.org/",
49    issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
50    test(no_crate_inject, attr(deny(warnings))),
51    test(attr(allow(dead_code, deprecated, unused_variables, unused_mut)))
52)]
53#![doc(rust_logo)]
54#![doc(cfg_hide(
55    no_fp_fmt_parse,
56    target_pointer_width = "16",
57    target_pointer_width = "32",
58    target_pointer_width = "64",
59    target_has_atomic = "8",
60    target_has_atomic = "16",
61    target_has_atomic = "32",
62    target_has_atomic = "64",
63    target_has_atomic = "ptr",
64    target_has_atomic_equal_alignment = "8",
65    target_has_atomic_equal_alignment = "16",
66    target_has_atomic_equal_alignment = "32",
67    target_has_atomic_equal_alignment = "64",
68    target_has_atomic_equal_alignment = "ptr",
69    target_has_atomic_load_store = "8",
70    target_has_atomic_load_store = "16",
71    target_has_atomic_load_store = "32",
72    target_has_atomic_load_store = "64",
73    target_has_atomic_load_store = "ptr",
74))]
75#![no_core]
76#![rustc_coherence_is_core]
77#![rustc_preserve_ub_checks]
78//
79// Lints:
80#![deny(rust_2021_incompatible_or_patterns)]
81#![deny(unsafe_op_in_unsafe_fn)]
82#![deny(fuzzy_provenance_casts)]
83#![warn(deprecated_in_future)]
84#![warn(missing_debug_implementations)]
85#![warn(missing_docs)]
86#![allow(explicit_outlives_requirements)]
87#![allow(incomplete_features)]
88#![warn(multiple_supertrait_upcastable)]
89#![allow(internal_features)]
90#![deny(ffi_unwind_calls)]
91#![warn(unreachable_pub)]
92// Do not check link redundancy on bootstraping phase
93#![allow(rustdoc::redundant_explicit_links)]
94#![warn(rustdoc::unescaped_backticks)]
95//
96// Library features:
97// tidy-alphabetical-start
98#![feature(array_ptr_get)]
99#![feature(asm_experimental_arch)]
100#![feature(bigint_helper_methods)]
101#![feature(bstr)]
102#![feature(bstr_internals)]
103#![feature(cfg_select)]
104#![feature(cfg_target_has_reliable_f16_f128)]
105#![feature(const_carrying_mul_add)]
106#![feature(const_eval_select)]
107#![feature(core_intrinsics)]
108#![feature(coverage_attribute)]
109#![feature(disjoint_bitor)]
110#![feature(internal_impls_macro)]
111#![feature(ip)]
112#![feature(is_ascii_octdigit)]
113#![feature(lazy_get)]
114#![feature(link_cfg)]
115#![feature(offset_of_enum)]
116#![feature(panic_internals)]
117#![feature(ptr_alignment_type)]
118#![feature(ptr_metadata)]
119#![feature(set_ptr_value)]
120#![feature(slice_as_array)]
121#![feature(slice_ptr_get)]
122#![feature(str_internals)]
123#![feature(str_split_inclusive_remainder)]
124#![feature(str_split_remainder)]
125#![feature(ub_checks)]
126#![feature(unchecked_neg)]
127#![feature(unchecked_shifts)]
128#![feature(unsafe_pinned)]
129#![feature(utf16_extra)]
130#![feature(variant_count)]
131// tidy-alphabetical-end
132//
133// Language features:
134// tidy-alphabetical-start
135#![feature(abi_unadjusted)]
136#![feature(adt_const_params)]
137#![feature(allow_internal_unsafe)]
138#![feature(allow_internal_unstable)]
139#![feature(auto_traits)]
140#![feature(cfg_sanitize)]
141#![feature(cfg_target_has_atomic)]
142#![feature(cfg_target_has_atomic_equal_alignment)]
143#![feature(cfg_ub_checks)]
144#![feature(const_precise_live_drops)]
145#![feature(const_trait_impl)]
146#![feature(decl_macro)]
147#![feature(deprecated_suggestion)]
148#![feature(doc_cfg)]
149#![feature(doc_cfg_hide)]
150#![feature(doc_notable_trait)]
151#![feature(extern_types)]
152#![feature(f128)]
153#![feature(f16)]
154#![feature(freeze_impls)]
155#![feature(fundamental)]
156#![feature(generic_arg_infer)]
157#![feature(if_let_guard)]
158#![feature(intra_doc_pointers)]
159#![feature(intrinsics)]
160#![feature(lang_items)]
161#![feature(link_llvm_intrinsics)]
162#![feature(macro_metavar_expr)]
163#![feature(marker_trait_attr)]
164#![feature(min_specialization)]
165#![feature(multiple_supertrait_upcastable)]
166#![feature(must_not_suspend)]
167#![feature(negative_impls)]
168#![feature(never_type)]
169#![feature(no_core)]
170#![feature(optimize_attribute)]
171#![feature(prelude_import)]
172#![feature(repr_simd)]
173#![feature(rustc_allow_const_fn_unstable)]
174#![feature(rustc_attrs)]
175#![feature(rustdoc_internals)]
176#![feature(simd_ffi)]
177#![feature(staged_api)]
178#![feature(stmt_expr_attributes)]
179#![feature(strict_provenance_lints)]
180#![feature(trait_alias)]
181#![feature(transparent_unions)]
182#![feature(try_blocks)]
183#![feature(unboxed_closures)]
184#![feature(unsized_fn_params)]
185#![feature(with_negative_coherence)]
186// tidy-alphabetical-end
187//
188// Target features:
189// tidy-alphabetical-start
190#![feature(aarch64_unstable_target_feature)]
191#![feature(arm_target_feature)]
192#![feature(hexagon_target_feature)]
193#![feature(keylocker_x86)]
194#![feature(loongarch_target_feature)]
195#![feature(mips_target_feature)]
196#![feature(powerpc_target_feature)]
197#![feature(riscv_target_feature)]
198#![feature(rtm_target_feature)]
199#![feature(s390x_target_feature)]
200#![feature(sha512_sm_x86)]
201#![feature(sse4a_target_feature)]
202#![feature(tbm_target_feature)]
203#![feature(wasm_target_feature)]
204#![feature(x86_amx_intrinsics)]
205// tidy-alphabetical-end
206
207// allow using `core::` in intra-doc links
208#[allow(unused_extern_crates)]
209extern crate self as core;
210
211#[prelude_import]
212#[allow(unused)]
213use prelude::rust_2024::*;
214
215#[macro_use]
216mod macros;
217
218#[unstable(feature = "assert_matches", issue = "82775")]
219/// Unstable module containing the unstable `assert_matches` macro.
220pub mod assert_matches {
221    #[unstable(feature = "assert_matches", issue = "82775")]
222    pub use crate::macros::{assert_matches, debug_assert_matches};
223}
224
225// We don't export this through #[macro_export] for now, to avoid breakage.
226#[unstable(feature = "autodiff", issue = "124509")]
227/// Unstable module containing the unstable `autodiff` macro.
228pub mod autodiff {
229    #[unstable(feature = "autodiff", issue = "124509")]
230    pub use crate::macros::builtin::{autodiff_forward, autodiff_reverse};
231}
232
233#[unstable(feature = "contracts", issue = "128044")]
234pub mod contracts;
235
236#[unstable(feature = "cfg_select", issue = "115585")]
237pub use crate::macros::cfg_select;
238
239#[macro_use]
240mod internal_macros;
241
242#[path = "num/shells/int_macros.rs"]
243#[macro_use]
244mod int_macros;
245
246#[rustc_diagnostic_item = "i128_legacy_mod"]
247#[path = "num/shells/i128.rs"]
248pub mod i128;
249#[rustc_diagnostic_item = "i16_legacy_mod"]
250#[path = "num/shells/i16.rs"]
251pub mod i16;
252#[rustc_diagnostic_item = "i32_legacy_mod"]
253#[path = "num/shells/i32.rs"]
254pub mod i32;
255#[rustc_diagnostic_item = "i64_legacy_mod"]
256#[path = "num/shells/i64.rs"]
257pub mod i64;
258#[rustc_diagnostic_item = "i8_legacy_mod"]
259#[path = "num/shells/i8.rs"]
260pub mod i8;
261#[rustc_diagnostic_item = "isize_legacy_mod"]
262#[path = "num/shells/isize.rs"]
263pub mod isize;
264
265#[rustc_diagnostic_item = "u128_legacy_mod"]
266#[path = "num/shells/u128.rs"]
267pub mod u128;
268#[rustc_diagnostic_item = "u16_legacy_mod"]
269#[path = "num/shells/u16.rs"]
270pub mod u16;
271#[rustc_diagnostic_item = "u32_legacy_mod"]
272#[path = "num/shells/u32.rs"]
273pub mod u32;
274#[rustc_diagnostic_item = "u64_legacy_mod"]
275#[path = "num/shells/u64.rs"]
276pub mod u64;
277#[rustc_diagnostic_item = "u8_legacy_mod"]
278#[path = "num/shells/u8.rs"]
279pub mod u8;
280#[rustc_diagnostic_item = "usize_legacy_mod"]
281#[path = "num/shells/usize.rs"]
282pub mod usize;
283
284#[path = "num/f128.rs"]
285pub mod f128;
286#[path = "num/f16.rs"]
287pub mod f16;
288#[path = "num/f32.rs"]
289pub mod f32;
290#[path = "num/f64.rs"]
291pub mod f64;
292
293#[macro_use]
294pub mod num;
295
296/* The core prelude, not as all-encompassing as the std prelude */
297
298pub mod prelude;
299
300/* Core modules for ownership management */
301
302pub mod hint;
303pub mod intrinsics;
304pub mod mem;
305pub mod ptr;
306#[unstable(feature = "ub_checks", issue = "none")]
307pub mod ub_checks;
308
309/* Core language traits */
310
311pub mod borrow;
312pub mod clone;
313pub mod cmp;
314pub mod convert;
315pub mod default;
316pub mod error;
317pub mod marker;
318pub mod ops;
319
320/* Core types and methods on primitives */
321
322pub mod any;
323pub mod array;
324pub mod ascii;
325pub mod asserting;
326#[unstable(feature = "async_iterator", issue = "79024")]
327pub mod async_iter;
328#[unstable(feature = "bstr", issue = "134915")]
329pub mod bstr;
330pub mod cell;
331pub mod char;
332pub mod ffi;
333#[unstable(feature = "core_io_borrowed_buf", issue = "117693")]
334pub mod io;
335pub mod iter;
336pub mod net;
337pub mod option;
338pub mod panic;
339pub mod panicking;
340#[unstable(feature = "pattern_type_macro", issue = "123646")]
341pub mod pat;
342pub mod pin;
343#[unstable(feature = "random", issue = "130703")]
344pub mod random;
345#[unstable(feature = "new_range_api", issue = "125687")]
346pub mod range;
347pub mod result;
348pub mod sync;
349#[unstable(feature = "unsafe_binders", issue = "130516")]
350pub mod unsafe_binder;
351
352pub mod fmt;
353pub mod hash;
354pub mod slice;
355pub mod str;
356pub mod time;
357
358pub mod unicode;
359
360/* Async */
361pub mod future;
362pub mod task;
363
364/* Heap memory allocator trait */
365#[allow(missing_docs)]
366pub mod alloc;
367
368// note: does not need to be public
369mod bool;
370mod escape;
371mod tuple;
372mod unit;
373
374#[stable(feature = "core_primitive", since = "1.43.0")]
375pub mod primitive;
376
377// Pull in the `core_arch` crate directly into core. The contents of
378// `core_arch` are in a different repository: rust-lang/stdarch.
379//
380// `core_arch` depends on core, but the contents of this module are
381// set up in such a way that directly pulling it here works such that the
382// crate uses the this crate as its core.
383#[path = "../../stdarch/crates/core_arch/src/mod.rs"]
384#[allow(
385    missing_docs,
386    missing_debug_implementations,
387    dead_code,
388    unused_imports,
389    unsafe_op_in_unsafe_fn,
390    ambiguous_glob_reexports,
391    deprecated_in_future,
392    unreachable_pub
393)]
394#[allow(rustdoc::bare_urls)]
395mod core_arch;
396
397#[stable(feature = "simd_arch", since = "1.27.0")]
398pub mod arch;
399
400// Pull in the `core_simd` crate directly into core. The contents of
401// `core_simd` are in a different repository: rust-lang/portable-simd.
402//
403// `core_simd` depends on core, but the contents of this module are
404// set up in such a way that directly pulling it here works such that the
405// crate uses this crate as its core.
406#[path = "../../portable-simd/crates/core_simd/src/mod.rs"]
407#[allow(missing_debug_implementations, dead_code, unsafe_op_in_unsafe_fn)]
408#[allow(rustdoc::bare_urls)]
409#[unstable(feature = "portable_simd", issue = "86656")]
410mod core_simd;
411
412#[unstable(feature = "portable_simd", issue = "86656")]
413pub mod simd {
414    #![doc = include_str!("../../portable-simd/crates/core_simd/src/core_simd_docs.md")]
415
416    #[unstable(feature = "portable_simd", issue = "86656")]
417    pub use crate::core_simd::simd::*;
418}
419
420include!("primitive_docs.rs");