1//! # The Rust Standard Library
2//!
3//! The Rust Standard Library is the foundation of portable Rust software, a
4//! set of minimal and battle-tested shared abstractions for the [broader Rust
5//! ecosystem][crates.io]. It offers core types, like [`Vec<T>`] and
6//! [`Option<T>`], library-defined [operations on language
7//! primitives](#primitives), [standard macros](#macros), [I/O] and
8//! [multithreading], among [many other things][other].
9//!
10//! `std` is available to all Rust crates by default. Therefore, the
11//! standard library can be accessed in [`use`] statements through the path
12//! `std`, as in [`use std::env`].
13//!
14//! # How to read this documentation
15//!
16//! If you already know the name of what you are looking for, the fastest way to
17//! find it is to use the <a href="#" onclick="window.searchState.focus();">search
18//! bar</a> at the top of the page.
19//!
20//! Otherwise, you may want to jump to one of these useful sections:
21//!
22//! * [`std::*` modules](#modules)
23//! * [Primitive types](#primitives)
24//! * [Standard macros](#macros)
25//! * [The Rust Prelude]
26//!
27//! If this is your first time, the documentation for the standard library is
28//! written to be casually perused. Clicking on interesting things should
29//! generally lead you to interesting places. Still, there are important bits
30//! you don't want to miss, so read on for a tour of the standard library and
31//! its documentation!
32//!
33//! Once you are familiar with the contents of the standard library you may
34//! begin to find the verbosity of the prose distracting. At this stage in your
35//! development you may want to press the `[-]` button near the top of the
36//! page to collapse it into a more skimmable view.
37//!
38//! While you are looking at that `[-]` button also notice the `source`
39//! link. Rust's API documentation comes with the source code and you are
40//! encouraged to read it. The standard library source is generally high
41//! quality and a peek behind the curtains is often enlightening.
42//!
43//! # What is in the standard library documentation?
44//!
45//! First of all, The Rust Standard Library is divided into a number of focused
46//! modules, [all listed further down this page](#modules). These modules are
47//! the bedrock upon which all of Rust is forged, and they have mighty names
48//! like [`std::slice`] and [`std::cmp`]. Modules' documentation typically
49//! includes an overview of the module along with examples, and are a smart
50//! place to start familiarizing yourself with the library.
51//!
52//! Second, implicit methods on [primitive types] are documented here. This can
53//! be a source of confusion for two reasons:
54//!
55//! 1. While primitives are implemented by the compiler, the standard library
56//! implements methods directly on the primitive types (and it is the only
57//! library that does so), which are [documented in the section on
58//! primitives](#primitives).
59//! 2. The standard library exports many modules *with the same name as
60//! primitive types*. These define additional items related to the primitive
61//! type, but not the all-important methods.
62//!
63//! So for example there is a [page for the primitive type
64//! `i32`](primitive::i32) that lists all the methods that can be called on
65//! 32-bit integers (very useful), and there is a [page for the module
66//! `std::i32`] that documents the constant values [`MIN`] and [`MAX`] (rarely
67//! useful).
68//!
69//! Note the documentation for the primitives [`str`] and [`[T]`][prim@slice] (also
70//! called 'slice'). Many method calls on [`String`] and [`Vec<T>`] are actually
71//! calls to methods on [`str`] and [`[T]`][prim@slice] respectively, via [deref
72//! coercions][deref-coercions].
73//!
74//! Third, the standard library defines [The Rust Prelude], a small collection
75//! of items - mostly traits - that are imported into every module of every
76//! crate. The traits in the prelude are pervasive, making the prelude
77//! documentation a good entry point to learning about the library.
78//!
79//! And finally, the standard library exports a number of standard macros, and
80//! [lists them on this page](#macros) (technically, not all of the standard
81//! macros are defined by the standard library - some are defined by the
82//! compiler - but they are documented here the same). Like the prelude, the
83//! standard macros are imported by default into all crates.
84//!
85//! # Contributing changes to the documentation
86//!
87//! Check out the Rust contribution guidelines [here](
88//! https://rustc-dev-guide.rust-lang.org/contributing.html#writing-documentation).
89//! The source for this documentation can be found on
90//! [GitHub](https://github.com/rust-lang/rust).
91//! To contribute changes, make sure you read the guidelines first, then submit
92//! pull-requests for your suggested changes.
93//!
94//! Contributions are appreciated! If you see a part of the docs that can be
95//! improved, submit a PR, or chat with us first on [Discord][rust-discord]
96//! #docs.
97//!
98//! # A Tour of The Rust Standard Library
99//!
100//! The rest of this crate documentation is dedicated to pointing out notable
101//! features of The Rust Standard Library.
102//!
103//! ## Containers and collections
104//!
105//! The [`option`] and [`result`] modules define optional and error-handling
106//! types, [`Option<T>`] and [`Result<T, E>`]. The [`iter`] module defines
107//! Rust's iterator trait, [`Iterator`], which works with the [`for`] loop to
108//! access collections.
109//!
110//! The standard library exposes three common ways to deal with contiguous
111//! regions of memory:
112//!
113//! * [`Vec<T>`] - A heap-allocated *vector* that is resizable at runtime.
114//! * [`[T; N]`][prim@array] - An inline *array* with a fixed size at compile time.
115//! * [`[T]`][prim@slice] - A dynamically sized *slice* into any other kind of contiguous
116//! storage, whether heap-allocated or not.
117//!
118//! Slices can only be handled through some kind of *pointer*, and as such come
119//! in many flavors such as:
120//!
121//! * `&[T]` - *shared slice*
122//! * `&mut [T]` - *mutable slice*
123//! * [`Box<[T]>`][owned slice] - *owned slice*
124//!
125//! [`str`], a UTF-8 string slice, is a primitive type, and the standard library
126//! defines many methods for it. Rust [`str`]s are typically accessed as
127//! immutable references: `&str`. Use the owned [`String`] for building and
128//! mutating strings.
129//!
130//! For converting to strings use the [`format!`] macro, and for converting from
131//! strings use the [`FromStr`] trait.
132//!
133//! Data may be shared by placing it in a reference-counted box or the [`Rc`]
134//! type, and if further contained in a [`Cell`] or [`RefCell`], may be mutated
135//! as well as shared. Likewise, in a concurrent setting it is common to pair an
136//! atomically-reference-counted box, [`Arc`], with a [`Mutex`] to get the same
137//! effect.
138//!
139//! The [`collections`] module defines maps, sets, linked lists and other
140//! typical collection types, including the common [`HashMap<K, V>`].
141//!
142//! ## Platform abstractions and I/O
143//!
144//! Besides basic data types, the standard library is largely concerned with
145//! abstracting over differences in common platforms, most notably Windows and
146//! Unix derivatives.
147//!
148//! Common types of I/O, including [files], [TCP], and [UDP], are defined in
149//! the [`io`], [`fs`], and [`net`] modules.
150//!
151//! The [`thread`] module contains Rust's threading abstractions. [`sync`]
152//! contains further primitive shared memory types, including [`atomic`] and
153//! [`mpsc`], which contains the channel types for message passing.
154//!
155//! # Use before and after `main()`
156//!
157//! Many parts of the standard library are expected to work before and after `main()`;
158//! but this is not guaranteed or ensured by tests. It is recommended that you write your own tests
159//! and run them on each platform you wish to support.
160//! This means that use of `std` before/after main, especially of features that interact with the
161//! OS or global state, is exempted from stability and portability guarantees and instead only
162//! provided on a best-effort basis. Nevertheless bug reports are appreciated.
163//!
164//! On the other hand `core` and `alloc` are most likely to work in such environments with
165//! the caveat that any hookable behavior such as panics, oom handling or allocators will also
166//! depend on the compatibility of the hooks.
167//!
168//! Some features may also behave differently outside main, e.g. stdio could become unbuffered,
169//! some panics might turn into aborts, backtraces might not get symbolicated or similar.
170//!
171//! Non-exhaustive list of known limitations:
172//!
173//! - after-main use of thread-locals, which also affects additional features:
174//! - [`thread::current()`]
175//! - [`thread::scope()`]
176//! - [`sync::mpsc`]
177//! - before-main stdio file descriptors are not guaranteed to be open on unix platforms
178//!
179//!
180//! [I/O]: io
181//! [`MIN`]: i32::MIN
182//! [`MAX`]: i32::MAX
183//! [page for the module `std::i32`]: crate::i32
184//! [TCP]: net::TcpStream
185//! [The Rust Prelude]: prelude
186//! [UDP]: net::UdpSocket
187//! [`Arc`]: sync::Arc
188//! [owned slice]: boxed
189//! [`Cell`]: cell::Cell
190//! [`FromStr`]: str::FromStr
191//! [`HashMap<K, V>`]: collections::HashMap
192//! [`Mutex`]: sync::Mutex
193//! [`Option<T>`]: option::Option
194//! [`Rc`]: rc::Rc
195//! [`RefCell`]: cell::RefCell
196//! [`Result<T, E>`]: result::Result
197//! [`Vec<T>`]: vec::Vec
198//! [`atomic`]: sync::atomic
199//! [`for`]: ../book/ch03-05-control-flow.html#looping-through-a-collection-with-for
200//! [`str`]: prim@str
201//! [`mpsc`]: sync::mpsc
202//! [`std::cmp`]: cmp
203//! [`std::slice`]: mod@slice
204//! [`use std::env`]: env/index.html
205//! [`use`]: ../book/ch07-02-defining-modules-to-control-scope-and-privacy.html
206//! [crates.io]: https://crates.io
207//! [deref-coercions]: ../book/ch15-02-deref.html#implicit-deref-coercions-with-functions-and-methods
208//! [files]: fs::File
209//! [multithreading]: thread
210//! [other]: #what-is-in-the-standard-library-documentation
211//! [primitive types]: ../book/ch03-02-data-types.html
212//! [rust-discord]: https://discord.gg/rust-lang
213//! [array]: prim@array
214//! [slice]: prim@slice
215
216#![cfg_attr(not(feature = "restricted-std"), stable(feature = "rust1", since = "1.0.0"))]
217#![cfg_attr(
218 feature = "restricted-std",
219 unstable(
220 feature = "restricted_std",
221 issue = "none",
222 reason = "You have attempted to use a standard library built for a platform that it doesn't \
223 know how to support. Consider building it for a known environment, disabling it with \
224 `#![no_std]` or overriding this warning by enabling this feature."
225 )
226)]
227#![cfg_attr(not(bootstrap), rustc_preserve_ub_checks)]
228#![doc(
229 html_playground_url = "https://play.rust-lang.org/",
230 issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
231 test(no_crate_inject, attr(deny(warnings))),
232 test(attr(allow(dead_code, deprecated, unused_variables, unused_mut)))
233)]
234#![doc(rust_logo)]
235#![doc(cfg_hide(
236 not(test),
237 not(any(test, bootstrap)),
238 no_global_oom_handling,
239 not(no_global_oom_handling)
240))]
241// Don't link to std. We are std.
242#![no_std]
243// Tell the compiler to link to either panic_abort or panic_unwind
244#![needs_panic_runtime]
245//
246// Lints:
247#![warn(deprecated_in_future)]
248#![warn(missing_docs)]
249#![warn(missing_debug_implementations)]
250#![allow(explicit_outlives_requirements)]
251#![allow(unused_lifetimes)]
252#![allow(internal_features)]
253#![deny(rustc::existing_doc_keyword)]
254#![deny(fuzzy_provenance_casts)]
255#![allow(rustdoc::redundant_explicit_links)]
256// Ensure that std can be linked against panic_abort despite compiled with `-C panic=unwind`
257#![deny(ffi_unwind_calls)]
258// std may use features in a platform-specific way
259#![allow(unused_features)]
260//
261// Features:
262#![cfg_attr(test, feature(internal_output_capture, print_internals, update_panic_count, rt))]
263#![cfg_attr(
264 all(target_vendor = "fortanix", target_env = "sgx"),
265 feature(slice_index_methods, coerce_unsized, sgx_platform)
266)]
267#![cfg_attr(any(windows, target_os = "uefi"), feature(round_char_boundary))]
268#![cfg_attr(target_family = "wasm", feature(stdarch_wasm_atomic_wait))]
269#![cfg_attr(
270 all(any(target_arch = "x86_64", target_arch = "x86"), target_os = "uefi"),
271 feature(stdarch_x86_has_cpuid)
272)]
273//
274// Language features:
275// tidy-alphabetical-start
276#![feature(alloc_error_handler)]
277#![feature(allocator_internals)]
278#![feature(allow_internal_unsafe)]
279#![feature(allow_internal_unstable)]
280#![feature(asm_experimental_arch)]
281#![feature(c_unwind)]
282#![feature(cfg_sanitizer_cfi)]
283#![feature(cfg_target_thread_local)]
284#![feature(cfi_encoding)]
285#![feature(concat_idents)]
286#![feature(const_mut_refs)]
287#![feature(const_trait_impl)]
288#![feature(decl_macro)]
289#![feature(deprecated_suggestion)]
290#![feature(doc_cfg)]
291#![feature(doc_cfg_hide)]
292#![feature(doc_masked)]
293#![feature(doc_notable_trait)]
294#![feature(dropck_eyepatch)]
295#![feature(f128)]
296#![feature(f16)]
297#![feature(if_let_guard)]
298#![feature(intra_doc_pointers)]
299#![feature(lang_items)]
300#![feature(let_chains)]
301#![feature(link_cfg)]
302#![feature(linkage)]
303#![feature(min_exhaustive_patterns)]
304#![feature(min_specialization)]
305#![feature(must_not_suspend)]
306#![feature(needs_panic_runtime)]
307#![feature(negative_impls)]
308#![feature(never_type)]
309#![feature(no_sanitize)]
310#![feature(prelude_import)]
311#![feature(rustc_attrs)]
312#![feature(rustdoc_internals)]
313#![feature(staged_api)]
314#![feature(thread_local)]
315#![feature(try_blocks)]
316#![feature(type_alias_impl_trait)]
317#![feature(utf8_chunks)]
318// tidy-alphabetical-end
319//
320// Library features (core):
321// tidy-alphabetical-start
322#![feature(c_str_module)]
323#![feature(char_internals)]
324#![feature(core_intrinsics)]
325#![feature(core_io_borrowed_buf)]
326#![feature(duration_constants)]
327#![feature(error_generic_member_access)]
328#![feature(error_in_core)]
329#![feature(error_iter)]
330#![feature(exact_size_is_empty)]
331#![feature(exclusive_wrapper)]
332#![feature(exposed_provenance)]
333#![feature(extend_one)]
334#![feature(float_gamma)]
335#![feature(float_minimum_maximum)]
336#![feature(float_next_up_down)]
337#![feature(fmt_internals)]
338#![feature(hasher_prefixfree_extras)]
339#![feature(hashmap_internals)]
340#![feature(hint_assert_unchecked)]
341#![feature(ip)]
342#![feature(maybe_uninit_slice)]
343#![feature(maybe_uninit_uninit_array)]
344#![feature(maybe_uninit_write_slice)]
345#![feature(panic_can_unwind)]
346#![feature(panic_info_message)]
347#![feature(panic_internals)]
348#![feature(pointer_is_aligned_to)]
349#![feature(portable_simd)]
350#![feature(prelude_2024)]
351#![feature(ptr_as_uninit)]
352#![feature(ptr_mask)]
353#![feature(slice_internals)]
354#![feature(slice_ptr_get)]
355#![feature(slice_range)]
356#![feature(std_internals)]
357#![feature(str_internals)]
358#![feature(strict_provenance)]
359#![feature(strict_provenance_atomic_ptr)]
360// tidy-alphabetical-end
361//
362// Library features (alloc):
363// tidy-alphabetical-start
364#![feature(alloc_layout_extra)]
365#![feature(allocator_api)]
366#![feature(get_mut_unchecked)]
367#![feature(map_try_insert)]
368#![feature(new_uninit)]
369#![feature(slice_concat_trait)]
370#![feature(thin_box)]
371#![feature(try_reserve_kind)]
372#![feature(vec_into_raw_parts)]
373// tidy-alphabetical-end
374//
375// Library features (unwind):
376// tidy-alphabetical-start
377#![feature(panic_unwind)]
378// tidy-alphabetical-end
379//
380// Library features (std_detect):
381// tidy-alphabetical-start
382#![feature(stdarch_internal)]
383// tidy-alphabetical-end
384//
385// Only for re-exporting:
386// tidy-alphabetical-start
387#![feature(assert_matches)]
388#![feature(async_iterator)]
389#![feature(c_variadic)]
390#![feature(cfg_accessible)]
391#![feature(cfg_eval)]
392#![feature(concat_bytes)]
393#![feature(const_format_args)]
394#![feature(custom_test_frameworks)]
395#![feature(edition_panic)]
396#![feature(format_args_nl)]
397#![feature(get_many_mut)]
398#![feature(lazy_cell)]
399#![feature(log_syntax)]
400#![feature(test)]
401#![feature(trace_macros)]
402// tidy-alphabetical-end
403//
404// Only used in tests/benchmarks:
405//
406// Only for const-ness:
407// tidy-alphabetical-start
408#![feature(const_collections_with_hasher)]
409#![feature(const_hash)]
410#![feature(const_ip)]
411#![feature(const_ipv4)]
412#![feature(const_ipv6)]
413#![feature(const_maybe_uninit_uninit_array)]
414#![feature(const_waker)]
415#![feature(thread_local_internals)]
416// tidy-alphabetical-end
417//
418#![default_lib_allocator]
419
420// Explicitly import the prelude. The compiler uses this same unstable attribute
421// to import the prelude implicitly when building crates that depend on std.
422#[prelude_import]
423#[allow(unused)]
424use prelude::rust_2021::*;
425
426// Access to Bencher, etc.
427#[cfg(test)]
428extern crate test;
429
430#[allow(unused_imports)] // macros from `alloc` are not used on all platforms
431#[macro_use]
432extern crate alloc as alloc_crate;
433
434// Many compiler tests depend on libc being pulled in by std
435// so include it here even if it's unused.
436#[doc(masked)]
437#[allow(unused_extern_crates)]
438extern crate libc;
439
440// We always need an unwinder currently for backtraces
441#[doc(masked)]
442#[allow(unused_extern_crates)]
443extern crate unwind;
444
445// FIXME: #94122 this extern crate definition only exist here to stop
446// miniz_oxide docs leaking into std docs. Find better way to do it.
447// Remove exclusion from tidy platform check when this removed.
448#[doc(masked)]
449#[allow(unused_extern_crates)]
450#[cfg(all(
451 not(all(windows, target_env = "msvc", not(target_vendor = "uwp"))),
452 feature = "miniz_oxide"
453))]
454extern crate miniz_oxide;
455
456// During testing, this crate is not actually the "real" std library, but rather
457// it links to the real std library, which was compiled from this same source
458// code. So any lang items std defines are conditionally excluded (or else they
459// would generate duplicate lang item errors), and any globals it defines are
460// _not_ the globals used by "real" std. So this import, defined only during
461// testing gives test-std access to real-std lang items and globals. See #2912
462#[cfg(test)]
463extern crate std as realstd;
464
465// The standard macros that are not built-in to the compiler.
466#[macro_use]
467mod macros;
468
469// The runtime entry point and a few unstable public functions used by the
470// compiler
471#[macro_use]
472pub mod rt;
473
474// The Rust prelude
475pub mod prelude;
476
477// Public module declarations and re-exports
478#[stable(feature = "rust1", since = "1.0.0")]
479pub use alloc_crate::borrow;
480#[stable(feature = "rust1", since = "1.0.0")]
481pub use alloc_crate::boxed;
482#[stable(feature = "rust1", since = "1.0.0")]
483pub use alloc_crate::fmt;
484#[stable(feature = "rust1", since = "1.0.0")]
485pub use alloc_crate::format;
486#[stable(feature = "rust1", since = "1.0.0")]
487pub use alloc_crate::rc;
488#[stable(feature = "rust1", since = "1.0.0")]
489pub use alloc_crate::slice;
490#[stable(feature = "rust1", since = "1.0.0")]
491pub use alloc_crate::str;
492#[stable(feature = "rust1", since = "1.0.0")]
493pub use alloc_crate::string;
494#[stable(feature = "rust1", since = "1.0.0")]
495pub use alloc_crate::vec;
496#[stable(feature = "rust1", since = "1.0.0")]
497pub use core::any;
498#[stable(feature = "core_array", since = "1.36.0")]
499pub use core::array;
500#[unstable(feature = "async_iterator", issue = "79024")]
501pub use core::async_iter;
502#[stable(feature = "rust1", since = "1.0.0")]
503pub use core::cell;
504#[stable(feature = "rust1", since = "1.0.0")]
505pub use core::char;
506#[stable(feature = "rust1", since = "1.0.0")]
507pub use core::clone;
508#[stable(feature = "rust1", since = "1.0.0")]
509pub use core::cmp;
510#[stable(feature = "rust1", since = "1.0.0")]
511pub use core::convert;
512#[stable(feature = "rust1", since = "1.0.0")]
513pub use core::default;
514#[stable(feature = "futures_api", since = "1.36.0")]
515pub use core::future;
516#[stable(feature = "core_hint", since = "1.27.0")]
517pub use core::hint;
518#[stable(feature = "i128", since = "1.26.0")]
519#[allow(deprecated, deprecated_in_future)]
520pub use core::i128;
521#[stable(feature = "rust1", since = "1.0.0")]
522#[allow(deprecated, deprecated_in_future)]
523pub use core::i16;
524#[stable(feature = "rust1", since = "1.0.0")]
525#[allow(deprecated, deprecated_in_future)]
526pub use core::i32;
527#[stable(feature = "rust1", since = "1.0.0")]
528#[allow(deprecated, deprecated_in_future)]
529pub use core::i64;
530#[stable(feature = "rust1", since = "1.0.0")]
531#[allow(deprecated, deprecated_in_future)]
532pub use core::i8;
533#[stable(feature = "rust1", since = "1.0.0")]
534pub use core::intrinsics;
535#[stable(feature = "rust1", since = "1.0.0")]
536#[allow(deprecated, deprecated_in_future)]
537pub use core::isize;
538#[stable(feature = "rust1", since = "1.0.0")]
539pub use core::iter;
540#[stable(feature = "rust1", since = "1.0.0")]
541pub use core::marker;
542#[stable(feature = "rust1", since = "1.0.0")]
543pub use core::mem;
544#[stable(feature = "rust1", since = "1.0.0")]
545pub use core::ops;
546#[stable(feature = "rust1", since = "1.0.0")]
547pub use core::option;
548#[stable(feature = "pin", since = "1.33.0")]
549pub use core::pin;
550#[stable(feature = "rust1", since = "1.0.0")]
551pub use core::ptr;
552#[stable(feature = "rust1", since = "1.0.0")]
553pub use core::result;
554#[stable(feature = "i128", since = "1.26.0")]
555#[allow(deprecated, deprecated_in_future)]
556pub use core::u128;
557#[stable(feature = "rust1", since = "1.0.0")]
558#[allow(deprecated, deprecated_in_future)]
559pub use core::u16;
560#[stable(feature = "rust1", since = "1.0.0")]
561#[allow(deprecated, deprecated_in_future)]
562pub use core::u32;
563#[stable(feature = "rust1", since = "1.0.0")]
564#[allow(deprecated, deprecated_in_future)]
565pub use core::u64;
566#[stable(feature = "rust1", since = "1.0.0")]
567#[allow(deprecated, deprecated_in_future)]
568pub use core::u8;
569#[stable(feature = "rust1", since = "1.0.0")]
570#[allow(deprecated, deprecated_in_future)]
571pub use core::usize;
572
573#[unstable(feature = "f128", issue = "116909")]
574pub mod f128;
575#[unstable(feature = "f16", issue = "116909")]
576pub mod f16;
577pub mod f32;
578pub mod f64;
579
580#[macro_use]
581pub mod thread;
582pub mod ascii;
583pub mod backtrace;
584pub mod collections;
585pub mod env;
586pub mod error;
587pub mod ffi;
588pub mod fs;
589pub mod hash;
590pub mod io;
591pub mod net;
592pub mod num;
593pub mod os;
594pub mod panic;
595#[cfg(not(bootstrap))]
596#[unstable(feature = "core_pattern_types", issue = "none")]
597pub mod pat;
598pub mod path;
599pub mod process;
600pub mod sync;
601pub mod time;
602
603// Pull in `std_float` crate into std. The contents of
604// `std_float` are in a different repository: rust-lang/portable-simd.
605#[path = "../../portable-simd/crates/std_float/src/lib.rs"]
606#[allow(missing_debug_implementations, dead_code, unsafe_op_in_unsafe_fn)]
607#[allow(rustdoc::bare_urls)]
608#[unstable(feature = "portable_simd", issue = "86656")]
609mod std_float;
610
611#[unstable(feature = "portable_simd", issue = "86656")]
612pub mod simd {
613 #![doc = include_str!("../../portable-simd/crates/core_simd/src/core_simd_docs.md")]
614
615 #[doc(inline)]
616 pub use crate::std_float::StdFloat;
617 #[doc(inline)]
618 pub use core::simd::*;
619}
620
621#[stable(feature = "futures_api", since = "1.36.0")]
622pub mod task {
623 //! Types and Traits for working with asynchronous tasks.
624
625 #[doc(inline)]
626 #[stable(feature = "futures_api", since = "1.36.0")]
627 pub use core::task::*;
628
629 #[doc(inline)]
630 #[stable(feature = "wake_trait", since = "1.51.0")]
631 pub use alloc::task::*;
632}
633
634#[doc = include_str!("../../stdarch/crates/core_arch/src/core_arch_docs.md")]
635#[stable(feature = "simd_arch", since = "1.27.0")]
636pub mod arch {
637 #[stable(feature = "simd_arch", since = "1.27.0")]
638 // The `no_inline`-attribute is required to make the documentation of all
639 // targets available.
640 // See https://github.com/rust-lang/rust/pull/57808#issuecomment-457390549 for
641 // more information.
642 #[doc(no_inline)] // Note (#82861): required for correct documentation
643 pub use core::arch::*;
644
645 #[stable(feature = "simd_aarch64", since = "1.60.0")]
646 pub use std_detect::is_aarch64_feature_detected;
647 #[unstable(feature = "stdarch_arm_feature_detection", issue = "111190")]
648 pub use std_detect::is_arm_feature_detected;
649 #[unstable(feature = "is_riscv_feature_detected", issue = "111192")]
650 pub use std_detect::is_riscv_feature_detected;
651 #[stable(feature = "simd_x86", since = "1.27.0")]
652 pub use std_detect::is_x86_feature_detected;
653 #[unstable(feature = "stdarch_mips_feature_detection", issue = "111188")]
654 pub use std_detect::{is_mips64_feature_detected, is_mips_feature_detected};
655 #[unstable(feature = "stdarch_powerpc_feature_detection", issue = "111191")]
656 pub use std_detect::{is_powerpc64_feature_detected, is_powerpc_feature_detected};
657}
658
659// This was stabilized in the crate root so we have to keep it there.
660#[stable(feature = "simd_x86", since = "1.27.0")]
661pub use std_detect::is_x86_feature_detected;
662
663// Platform-abstraction modules
664mod sys;
665mod sys_common;
666
667pub mod alloc;
668
669// Private support modules
670mod panicking;
671
672#[path = "../../backtrace/src/lib.rs"]
673#[allow(dead_code, unused_attributes, fuzzy_provenance_casts)]
674mod backtrace_rs;
675
676// Re-export macros defined in core.
677#[stable(feature = "rust1", since = "1.0.0")]
678#[allow(deprecated, deprecated_in_future)]
679pub use core::{
680 assert_eq, assert_ne, debug_assert, debug_assert_eq, debug_assert_ne, matches, todo, r#try,
681 unimplemented, unreachable, write, writeln,
682};
683
684// Re-export built-in macros defined through core.
685#[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
686#[allow(deprecated)]
687pub use core::{
688 assert, assert_matches, cfg, column, compile_error, concat, concat_idents, const_format_args,
689 env, file, format_args, format_args_nl, include, include_bytes, include_str, line, log_syntax,
690 module_path, option_env, stringify, trace_macros,
691};
692
693#[unstable(
694 feature = "concat_bytes",
695 issue = "87555",
696 reason = "`concat_bytes` is not stable enough for use and is subject to change"
697)]
698pub use core::concat_bytes;
699
700#[unstable(feature = "cfg_match", issue = "115585")]
701pub use core::cfg_match;
702
703#[stable(feature = "core_primitive", since = "1.43.0")]
704pub use core::primitive;
705
706// Include a number of private modules that exist solely to provide
707// the rustdoc documentation for primitive types. Using `include!`
708// because rustdoc only looks for these modules at the crate level.
709include!("../../core/src/primitive_docs.rs");
710
711// Include a number of private modules that exist solely to provide
712// the rustdoc documentation for the existing keywords. Using `include!`
713// because rustdoc only looks for these modules at the crate level.
714include!("keyword_docs.rs");
715
716// This is required to avoid an unstable error when `restricted-std` is not
717// enabled. The use of #![feature(restricted_std)] in rustc-std-workspace-std
718// is unconditional, so the unstable feature needs to be defined somewhere.
719#[unstable(feature = "restricted_std", issue = "none")]
720mod __restricted_std_workaround {}
721
722mod sealed {
723 /// This trait being unreachable from outside the crate
724 /// prevents outside implementations of our extension traits.
725 /// This allows adding more trait methods in the future.
726 #[unstable(feature = "sealed", issue = "none")]
727 pub trait Sealed {}
728}
729
730#[cfg(test)]
731#[allow(dead_code)] // Not used in all configurations.
732pub(crate) mod test_helpers {
733 /// Test-only replacement for `rand::thread_rng()`, which is unusable for
734 /// us, as we want to allow running stdlib tests on tier-3 targets which may
735 /// not have `getrandom` support.
736 ///
737 /// Does a bit of a song and dance to ensure that the seed is different on
738 /// each call (as some tests sadly rely on this), but doesn't try that hard.
739 ///
740 /// This is duplicated in the `core`, `alloc` test suites (as well as
741 /// `std`'s integration tests), but figuring out a mechanism to share these
742 /// seems far more painful than copy-pasting a 7 line function a couple
743 /// times, given that even under a perma-unstable feature, I don't think we
744 /// want to expose types from `rand` from `std`.
745 #[track_caller]
746 pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng {
747 use core::hash::{BuildHasher, Hash, Hasher};
748 let mut hasher = crate::hash::RandomState::new().build_hasher();
749 core::panic::Location::caller().hash(&mut hasher);
750 let hc64 = hasher.finish();
751 let seed_vec = hc64.to_le_bytes().into_iter().chain(0u8..8).collect::<Vec<u8>>();
752 let seed: [u8; 16] = seed_vec.as_slice().try_into().unwrap();
753 rand::SeedableRng::from_seed(seed)
754 }
755}
756