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_match)]
104#![feature(const_carrying_mul_add)]
105#![feature(const_eval_select)]
106#![feature(core_intrinsics)]
107#![feature(coverage_attribute)]
108#![feature(disjoint_bitor)]
109#![feature(internal_impls_macro)]
110#![feature(ip)]
111#![feature(is_ascii_octdigit)]
112#![feature(lazy_get)]
113#![feature(link_cfg)]
114#![feature(non_null_from_ref)]
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_as_chunks)]
122#![feature(slice_ptr_get)]
123#![feature(str_internals)]
124#![feature(str_split_inclusive_remainder)]
125#![feature(str_split_remainder)]
126#![feature(ub_checks)]
127#![feature(unchecked_neg)]
128#![feature(unchecked_shifts)]
129#![feature(unsafe_pinned)]
130#![feature(utf16_extra)]
131#![feature(variant_count)]
132// tidy-alphabetical-end
133//
134// Language features:
135// tidy-alphabetical-start
136#![feature(abi_unadjusted)]
137#![feature(adt_const_params)]
138#![feature(allow_internal_unsafe)]
139#![feature(allow_internal_unstable)]
140#![feature(auto_traits)]
141#![feature(cfg_sanitize)]
142#![feature(cfg_target_has_atomic)]
143#![feature(cfg_target_has_atomic_equal_alignment)]
144#![feature(cfg_ub_checks)]
145#![feature(const_precise_live_drops)]
146#![feature(const_trait_impl)]
147#![feature(decl_macro)]
148#![feature(deprecated_suggestion)]
149#![feature(doc_cfg)]
150#![feature(doc_cfg_hide)]
151#![feature(doc_notable_trait)]
152#![feature(extern_types)]
153#![feature(f128)]
154#![feature(f16)]
155#![feature(freeze_impls)]
156#![feature(fundamental)]
157#![feature(generic_arg_infer)]
158#![feature(if_let_guard)]
159#![feature(intra_doc_pointers)]
160#![feature(intrinsics)]
161#![feature(lang_items)]
162#![feature(let_chains)]
163#![feature(link_llvm_intrinsics)]
164#![feature(macro_metavar_expr)]
165#![feature(marker_trait_attr)]
166#![feature(min_specialization)]
167#![feature(multiple_supertrait_upcastable)]
168#![feature(must_not_suspend)]
169#![feature(negative_impls)]
170#![feature(never_type)]
171#![feature(no_core)]
172#![feature(optimize_attribute)]
173#![feature(prelude_import)]
174#![feature(repr_simd)]
175#![feature(rustc_allow_const_fn_unstable)]
176#![feature(rustc_attrs)]
177#![feature(rustdoc_internals)]
178#![feature(simd_ffi)]
179#![feature(staged_api)]
180#![feature(stmt_expr_attributes)]
181#![feature(strict_provenance_lints)]
182#![feature(trait_alias)]
183#![feature(transparent_unions)]
184#![feature(try_blocks)]
185#![feature(unboxed_closures)]
186#![feature(unsized_fn_params)]
187#![feature(with_negative_coherence)]
188// tidy-alphabetical-end
189//
190// Target features:
191// tidy-alphabetical-start
192#![feature(aarch64_unstable_target_feature)]
193#![feature(arm_target_feature)]
194#![feature(avx512_target_feature)]
195#![feature(hexagon_target_feature)]
196#![feature(keylocker_x86)]
197#![feature(loongarch_target_feature)]
198#![feature(mips_target_feature)]
199#![feature(powerpc_target_feature)]
200#![feature(riscv_target_feature)]
201#![feature(rtm_target_feature)]
202#![feature(s390x_target_feature)]
203#![feature(sha512_sm_x86)]
204#![feature(sse4a_target_feature)]
205#![feature(tbm_target_feature)]
206#![feature(wasm_target_feature)]
207#![feature(x86_amx_intrinsics)]
208// tidy-alphabetical-end
209
210// allow using `core::` in intra-doc links
211#[allow(unused_extern_crates)]
212extern crate self as core;
213
214#[prelude_import]
215#[allow(unused)]
216use prelude::rust_2024::*;
217
218#[macro_use]
219mod macros;
220
221#[unstable(feature = "assert_matches", issue = "82775")]
222/// Unstable module containing the unstable `assert_matches` macro.
223pub mod assert_matches {
224    #[unstable(feature = "assert_matches", issue = "82775")]
225    pub use crate::macros::{assert_matches, debug_assert_matches};
226}
227
228// We don't export this through #[macro_export] for now, to avoid breakage.
229#[unstable(feature = "autodiff", issue = "124509")]
230/// Unstable module containing the unstable `autodiff` macro.
231pub mod autodiff {
232    #[unstable(feature = "autodiff", issue = "124509")]
233    pub use crate::macros::builtin::autodiff;
234}
235
236#[unstable(feature = "contracts", issue = "128044")]
237pub mod contracts;
238
239#[unstable(feature = "cfg_match", issue = "115585")]
240pub use crate::macros::cfg_match;
241
242#[macro_use]
243mod internal_macros;
244
245#[path = "num/shells/int_macros.rs"]
246#[macro_use]
247mod int_macros;
248
249#[rustc_diagnostic_item = "i128_legacy_mod"]
250#[path = "num/shells/i128.rs"]
251pub mod i128;
252#[rustc_diagnostic_item = "i16_legacy_mod"]
253#[path = "num/shells/i16.rs"]
254pub mod i16;
255#[rustc_diagnostic_item = "i32_legacy_mod"]
256#[path = "num/shells/i32.rs"]
257pub mod i32;
258#[rustc_diagnostic_item = "i64_legacy_mod"]
259#[path = "num/shells/i64.rs"]
260pub mod i64;
261#[rustc_diagnostic_item = "i8_legacy_mod"]
262#[path = "num/shells/i8.rs"]
263pub mod i8;
264#[rustc_diagnostic_item = "isize_legacy_mod"]
265#[path = "num/shells/isize.rs"]
266pub mod isize;
267
268#[rustc_diagnostic_item = "u128_legacy_mod"]
269#[path = "num/shells/u128.rs"]
270pub mod u128;
271#[rustc_diagnostic_item = "u16_legacy_mod"]
272#[path = "num/shells/u16.rs"]
273pub mod u16;
274#[rustc_diagnostic_item = "u32_legacy_mod"]
275#[path = "num/shells/u32.rs"]
276pub mod u32;
277#[rustc_diagnostic_item = "u64_legacy_mod"]
278#[path = "num/shells/u64.rs"]
279pub mod u64;
280#[rustc_diagnostic_item = "u8_legacy_mod"]
281#[path = "num/shells/u8.rs"]
282pub mod u8;
283#[rustc_diagnostic_item = "usize_legacy_mod"]
284#[path = "num/shells/usize.rs"]
285pub mod usize;
286
287#[path = "num/f128.rs"]
288pub mod f128;
289#[path = "num/f16.rs"]
290pub mod f16;
291#[path = "num/f32.rs"]
292pub mod f32;
293#[path = "num/f64.rs"]
294pub mod f64;
295
296#[macro_use]
297pub mod num;
298
299/* The core prelude, not as all-encompassing as the std prelude */
300
301pub mod prelude;
302
303/* Core modules for ownership management */
304
305pub mod hint;
306pub mod intrinsics;
307pub mod mem;
308pub mod ptr;
309#[unstable(feature = "ub_checks", issue = "none")]
310pub mod ub_checks;
311
312/* Core language traits */
313
314pub mod borrow;
315pub mod clone;
316pub mod cmp;
317pub mod convert;
318pub mod default;
319pub mod error;
320pub mod marker;
321pub mod ops;
322
323/* Core types and methods on primitives */
324
325pub mod any;
326pub mod array;
327pub mod ascii;
328pub mod asserting;
329#[unstable(feature = "async_iterator", issue = "79024")]
330pub mod async_iter;
331#[unstable(feature = "bstr", issue = "134915")]
332pub mod bstr;
333pub mod cell;
334pub mod char;
335pub mod ffi;
336#[unstable(feature = "core_io_borrowed_buf", issue = "117693")]
337pub mod io;
338pub mod iter;
339pub mod net;
340pub mod option;
341pub mod panic;
342pub mod panicking;
343#[unstable(feature = "pattern_type_macro", issue = "123646")]
344pub mod pat;
345pub mod pin;
346#[unstable(feature = "random", issue = "130703")]
347pub mod random;
348#[unstable(feature = "new_range_api", issue = "125687")]
349pub mod range;
350pub mod result;
351pub mod sync;
352#[unstable(feature = "unsafe_binders", issue = "130516")]
353pub mod unsafe_binder;
354
355pub mod fmt;
356pub mod hash;
357pub mod slice;
358pub mod str;
359pub mod time;
360
361pub mod unicode;
362
363/* Async */
364pub mod future;
365pub mod task;
366
367/* Heap memory allocator trait */
368#[allow(missing_docs)]
369pub mod alloc;
370
371// note: does not need to be public
372mod bool;
373mod escape;
374mod tuple;
375mod unit;
376
377#[stable(feature = "core_primitive", since = "1.43.0")]
378pub mod primitive;
379
380// Pull in the `core_arch` crate directly into core. The contents of
381// `core_arch` are in a different repository: rust-lang/stdarch.
382//
383// `core_arch` depends on core, but the contents of this module are
384// set up in such a way that directly pulling it here works such that the
385// crate uses the this crate as its core.
386#[path = "../../stdarch/crates/core_arch/src/mod.rs"]
387#[allow(
388    missing_docs,
389    missing_debug_implementations,
390    dead_code,
391    unused_imports,
392    unsafe_op_in_unsafe_fn,
393    ambiguous_glob_reexports,
394    deprecated_in_future,
395    unreachable_pub
396)]
397#[allow(rustdoc::bare_urls)]
398mod core_arch;
399
400#[stable(feature = "simd_arch", since = "1.27.0")]
401pub mod arch;
402
403// Pull in the `core_simd` crate directly into core. The contents of
404// `core_simd` are in a different repository: rust-lang/portable-simd.
405//
406// `core_simd` depends on core, but the contents of this module are
407// set up in such a way that directly pulling it here works such that the
408// crate uses this crate as its core.
409#[path = "../../portable-simd/crates/core_simd/src/mod.rs"]
410#[allow(missing_debug_implementations, dead_code, unsafe_op_in_unsafe_fn)]
411#[allow(rustdoc::bare_urls)]
412#[unstable(feature = "portable_simd", issue = "86656")]
413mod core_simd;
414
415#[unstable(feature = "portable_simd", issue = "86656")]
416pub mod simd {
417    #![doc = include_str!("../../portable-simd/crates/core_simd/src/core_simd_docs.md")]
418
419    #[unstable(feature = "portable_simd", issue = "86656")]
420    pub use crate::core_simd::simd::*;
421}
422
423include!("primitive_docs.rs");