//! # The Rust core allocation and collections library //! //! This library provides smart pointers and collections for managing //! heap-allocated values. //! //! This library, like core, normally doesn’t need to be used directly //! since its contents are re-exported in the [`std` crate](../std/index.html). //! Crates that use the `#![no_std]` attribute however will typically //! not depend on `std`, so they’d use this crate instead. //! //! ## Boxed values //! //! The [`Box`] type is a smart pointer type. There can only be one owner of a //! [`Box`], and the owner can decide to mutate the contents, which live on the //! heap. //! //! This type can be sent among threads efficiently as the size of a `Box` value //! is the same as that of a pointer. Tree-like data structures are often built //! with boxes because each node often has only one owner, the parent. //! //! ## Reference counted pointers //! //! The [`Rc`] type is a non-threadsafe reference-counted pointer type intended //! for sharing memory within a thread. An [`Rc`] pointer wraps a type, `T`, and //! only allows access to `&T`, a shared reference. //! //! This type is useful when inherited mutability (such as using [`Box`]) is too //! constraining for an application, and is often paired with the [`Cell`] or //! [`RefCell`] types in order to allow mutation. //! //! ## Atomically reference counted pointers //! //! The [`Arc`] type is the threadsafe equivalent of the [`Rc`] type. It //! provides all the same functionality of [`Rc`], except it requires that the //! contained type `T` is shareable. Additionally, [`Arc`][`Arc`] is itself //! sendable while [`Rc`][`Rc`] is not. //! //! This type allows for shared access to the contained data, and is often //! paired with synchronization primitives such as mutexes to allow mutation of //! shared resources. //! //! ## Collections //! //! Implementations of the most common general purpose data structures are //! defined in this library. They are re-exported through the //! [standard collections library](../std/collections/index.html). //! //! ## Heap interfaces //! //! The [`alloc`](alloc/index.html) module defines the low-level interface to the //! default global allocator. It is not compatible with the libc allocator API. //! //! [`Arc`]: sync //! [`Box`]: boxed //! [`Cell`]: core::cell //! [`Rc`]: rc //! [`RefCell`]: core::cell #![allow(incomplete_features)] #![allow(unused_attributes)] #![stable(feature = "alloc", since = "1.36.0")] #![doc( html_playground_url = "https://play.rust-lang.org/", issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/", test(no_crate_inject, attr(allow(unused_variables), deny(warnings))) )] #![doc(cfg_hide( not(test), not(any(test, bootstrap)), no_global_oom_handling, not(no_global_oom_handling), not(no_rc), not(no_sync), target_has_atomic = "ptr" ))] #![doc(rust_logo)] #![feature(rustdoc_internals)] #![no_std] #![needs_allocator] // Lints: #![deny(unsafe_op_in_unsafe_fn)] #![deny(fuzzy_provenance_casts)] #![warn(deprecated_in_future)] #![warn(missing_debug_implementations)] #![warn(missing_docs)] #![allow(explicit_outlives_requirements)] #![warn(multiple_supertrait_upcastable)] #![allow(internal_features)] #![allow(rustdoc::redundant_explicit_links)] #![warn(rustdoc::unescaped_backticks)] #![deny(ffi_unwind_calls)] #![warn(unreachable_pub)] // // Library features: // tidy-alphabetical-start #![feature(alloc_layout_extra)] #![feature(allocator_api)] #![feature(array_chunks)] #![feature(array_into_iter_constructors)] #![feature(array_windows)] #![feature(ascii_char)] #![feature(assert_matches)] #![feature(async_fn_traits)] #![feature(async_iterator)] #![feature(bstr)] #![feature(bstr_internals)] #![feature(char_max_len)] #![feature(clone_to_uninit)] #![feature(coerce_unsized)] #![feature(const_eval_select)] #![feature(const_heap)] #![feature(core_intrinsics)] #![feature(deprecated_suggestion)] #![feature(deref_pure_trait)] #![feature(dispatch_from_dyn)] #![feature(ergonomic_clones)] #![feature(error_generic_member_access)] #![feature(exact_size_is_empty)] #![feature(extend_one)] #![feature(extend_one_unchecked)] #![feature(fmt_internals)] #![feature(fn_traits)] #![feature(formatting_options)] #![feature(hasher_prefixfree_extras)] #![feature(inplace_iteration)] #![feature(iter_advance_by)] #![feature(iter_next_chunk)] #![feature(layout_for_ptr)] #![feature(legacy_receiver_trait)] #![feature(local_waker)] #![feature(maybe_uninit_slice)] #![feature(maybe_uninit_uninit_array_transpose)] #![feature(nonnull_provenance)] #![feature(panic_internals)] #![feature(pattern)] #![feature(pin_coerce_unsized_trait)] #![feature(pointer_like_trait)] #![feature(ptr_internals)] #![feature(ptr_metadata)] #![feature(set_ptr_value)] #![feature(sized_type_properties)] #![feature(slice_from_ptr_range)] #![feature(slice_index_methods)] #![feature(slice_iter_mut_as_mut_slice)] #![feature(slice_ptr_get)] #![feature(slice_range)] #![feature(std_internals)] #![feature(str_internals)] #![feature(temporary_niche_types)] #![feature(trusted_fused)] #![feature(trusted_len)] #![feature(trusted_random_access)] #![feature(try_trait_v2)] #![feature(try_with_capacity)] #![feature(tuple_trait)] #![feature(unicode_internals)] #![feature(unsize)] #![feature(unwrap_infallible)] // tidy-alphabetical-end // // Language features: // tidy-alphabetical-start #![feature(allocator_internals)] #![feature(allow_internal_unstable)] #![feature(cfg_sanitize)] #![feature(const_precise_live_drops)] #![feature(coroutine_trait)] #![feature(decl_macro)] #![feature(dropck_eyepatch)] #![feature(fundamental)] #![feature(hashmap_internals)] #![feature(intrinsics)] #![feature(lang_items)] #![feature(min_specialization)] #![feature(multiple_supertrait_upcastable)] #![feature(negative_impls)] #![feature(never_type)] #![feature(optimize_attribute)] #![feature(rustc_allow_const_fn_unstable)] #![feature(rustc_attrs)] #![feature(slice_internals)] #![feature(staged_api)] #![feature(stmt_expr_attributes)] #![feature(strict_provenance_lints)] #![feature(unboxed_closures)] #![feature(unsized_fn_params)] #![feature(with_negative_coherence)] #![rustc_preserve_ub_checks] // tidy-alphabetical-end // // Rustdoc features: #![feature(doc_cfg)] #![feature(doc_cfg_hide)] // Technically, this is a bug in rustdoc: rustdoc sees the documentation on `#[lang = slice_alloc]` // blocks is for `&[T]`, which also has documentation using this feature in `core`, and gets mad // that the feature-gate isn't enabled. Ideally, it wouldn't check for the feature gate for docs // from other crates, but since this can only appear for lang items, it doesn't seem worth fixing. #![feature(intra_doc_pointers)] // Module with internal macros used by other modules (needs to be included before other modules). #[macro_use] mod macros; mod raw_vec; // Heaps provided for low-level allocation strategies pub mod alloc; // Primitive types using the heaps above // Need to conditionally define the mod from `boxed.rs` to avoid // duplicating the lang-items when building in test cfg; but also need // to allow code to have `use boxed::Box;` declarations. pub mod borrow; pub mod boxed; #[unstable(feature = "bstr", issue = "134915")] pub mod bstr; pub mod collections; #[cfg(all(not(no_rc), not(no_sync), not(no_global_oom_handling)))] pub mod ffi; pub mod fmt; #[cfg(not(no_rc))] pub mod rc; pub mod slice; pub mod str; pub mod string; #[cfg(all(not(no_rc), not(no_sync), target_has_atomic = "ptr"))] pub mod sync; #[cfg(all(not(no_global_oom_handling), not(no_rc), not(no_sync)))] pub mod task; pub mod vec; #[doc(hidden)] #[unstable(feature = "liballoc_internals", issue = "none", reason = "implementation detail")] pub mod __export { pub use core::format_args; pub use core::hint::must_use; }