// SPDX-License-Identifier: Apache-2.0 OR MIT //! # 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<T>`][`Arc`] is itself//! sendable while [`Rc<T>`][`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 // To run alloc tests without x.py without ending up with two copies of alloc, Miri needs to be// able to "empty" this crate. See <https://github.com/rust-lang/miri-test-libstd/issues/4>.// rustc itself never sets the feature, so this line has no effect there.#![cfg(any(not(feature = "miri-test-libstd"), test, doctest))]//#![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)), any(not(feature = "miri-test-libstd"), test, doctest), 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)]//// Library features:// tidy-alphabetical-start#![cfg_attr(not(no_global_oom_handling), feature(const_alloc_error))]#![cfg_attr(not(no_global_oom_handling), feature(const_btree_len))]#![cfg_attr(test, feature(is_sorted))]#![cfg_attr(test, feature(new_uninit))]#![feature(alloc_layout_extra)]#![feature(allocator_api)]#![feature(array_chunks)]#![feature(array_into_iter_constructors)]#![feature(array_methods)]#![feature(array_windows)]#![feature(ascii_char)]#![feature(assert_matches)]#![feature(async_iterator)]#![feature(coerce_unsized)]#![feature(const_align_of_val)]#![feature(const_box)]#![cfg_attr(not(no_borrow), feature(const_cow_is_borrowed))]#![feature(const_eval_select)]#![feature(const_maybe_uninit_as_mut_ptr)]#![feature(const_maybe_uninit_write)]#![feature(const_pin)]#![feature(const_refs_to_cell)]#![feature(const_size_of_val)]#![feature(const_waker)]#![feature(core_intrinsics)]#![feature(core_panic)]#![feature(deprecated_suggestion)]#![feature(dispatch_from_dyn)]#![feature(error_generic_member_access)]#![feature(error_in_core)]#![feature(exact_size_is_empty)]#![feature(extend_one)]#![feature(fmt_internals)]#![feature(fn_traits)]#![feature(hasher_prefixfree_extras)]#![feature(inline_const)]#![feature(inplace_iteration)]#![feature(iter_advance_by)]#![feature(iter_next_chunk)]#![feature(iter_repeat_n)]#![feature(layout_for_ptr)]#![feature(maybe_uninit_slice)]#![feature(maybe_uninit_uninit_array)]#![feature(maybe_uninit_uninit_array_transpose)]#![feature(pattern)]#![feature(ptr_internals)]#![feature(ptr_metadata)]#![feature(ptr_sub_ptr)]#![feature(receiver_trait)]#![feature(set_ptr_value)]#![feature(sized_type_properties)]#![feature(slice_from_ptr_range)]#![feature(slice_group_by)]#![feature(slice_ptr_get)]#![feature(slice_ptr_len)]#![feature(slice_range)]#![feature(std_internals)]#![feature(str_internals)]#![feature(strict_provenance)]#![feature(trusted_fused)]#![feature(trusted_len)]#![feature(trusted_random_access)]#![feature(try_trait_v2)]#![feature(tuple_trait)]#![feature(unchecked_math)]#![feature(unicode_internals)]#![feature(unsize)]#![feature(utf8_chunks)]// tidy-alphabetical-end//// Language features:// tidy-alphabetical-start#![cfg_attr(not(test), feature(coroutine_trait))]#![cfg_attr(test, feature(panic_update_hook))]#![cfg_attr(test, feature(test))]#![feature(allocator_internals)]#![feature(allow_internal_unstable)]#![feature(associated_type_bounds)]#![feature(c_unwind)]#![feature(cfg_sanitize)]#![feature(const_mut_refs)]#![feature(const_precise_live_drops)]#![feature(const_ptr_write)]#![feature(const_trait_impl)]#![feature(const_try)]#![feature(dropck_eyepatch)]#![feature(exclusive_range_pattern)]#![feature(fundamental)]#![feature(hashmap_internals)]#![feature(lang_items)]#![feature(min_specialization)]#![feature(multiple_supertrait_upcastable)]#![feature(negative_impls)]#![feature(never_type)]#![feature(pointer_is_aligned)]#![feature(rustc_allow_const_fn_unstable)]#![feature(rustc_attrs)]#![feature(slice_internals)]#![feature(staged_api)]#![feature(stmt_expr_attributes)]#![feature(unboxed_closures)]#![feature(unsized_fn_params)]#![feature(with_negative_coherence)]// 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)] // Allow testing this library#[cfg(test)]#[macro_use]extern crate std;#[cfg(test)]extern crate test;#[cfg(test)]mod testing; // Module with internal macros used by other modules (needs to be included before other modules).#[cfg(not(no_macros))]#[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.#[cfg(not(test))]pub mod boxed;#[cfg(test)]mod boxed { pub use std::boxed::Box;}#[cfg(not(no_borrow))]pub mod borrow;pub mod collections;#[cfg(all(not(no_rc), not(no_sync), not(no_global_oom_handling)))]pub mod ffi;#[cfg(not(no_fmt))]pub mod fmt;#[cfg(not(no_rc))]pub mod rc;pub mod slice;#[cfg(not(no_str))]pub mod str;#[cfg(not(no_string))]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), target_has_atomic = "ptr"))]pub mod task;#[cfg(test)]mod tests;pub mod vec; #[doc(hidden)]#[unstable(feature = "liballoc_internals", issue = "none", reason = "implementation detail")]pub mod __export { pub use core::format_args;} #[cfg(test)]#[allow(dead_code)] // Not used in all configurationspub(crate) mod test_helpers { /// Copied from `std::test_helpers::test_rng`, since these tests rely on the /// seed not being the same for every RNG invocation too. pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng { use std::hash::{BuildHasher, Hash, Hasher}; let mut hasher = std::hash::RandomState::new().build_hasher(); std::panic::Location::caller().hash(&mut hasher); let hc64 = hasher.finish(); let seed_vec = hc64.to_le_bytes().into_iter().chain(0u8..8).collect::<crate::vec::Vec<u8>>(); let seed: [u8; 16] = seed_vec.as_slice().try_into().unwrap(); rand::SeedableRng::from_seed(seed) }}
// SPDX-License-Identifier: Apache-2.0 OR MIT
//! # 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<T>`][`Arc`] is itself
//! sendable while [`Rc<T>`][`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
// To run alloc tests without x.py without ending up with two copies of alloc, Miri needs to be
// able to "empty" this crate. See <https://github.com/rust-lang/miri-test-libstd/issues/4>.
// rustc itself never sets the feature, so this line has no effect there.
#![cfg(any(not(feature = "miri-test-libstd"), test, doctest))]
//
#![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)),
any(not(feature = "miri-test-libstd"), test, doctest),
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)]
//
// Library features:
// tidy-alphabetical-start
#![cfg_attr(not(no_global_oom_handling), feature(const_alloc_error))]
#![cfg_attr(not(no_global_oom_handling), feature(const_btree_len))]
#![cfg_attr(test, feature(is_sorted))]
#![cfg_attr(test, feature(new_uninit))]
#![feature(alloc_layout_extra)]
#![feature(allocator_api)]
#![feature(array_chunks)]
#![feature(array_into_iter_constructors)]
#![feature(array_methods)]
#![feature(array_windows)]
#![feature(ascii_char)]
#![feature(assert_matches)]
#![feature(async_iterator)]
#![feature(coerce_unsized)]
#![feature(const_align_of_val)]
#![feature(const_box)]
#![cfg_attr(not(no_borrow), feature(const_cow_is_borrowed))]
#![feature(const_eval_select)]
#![feature(const_maybe_uninit_as_mut_ptr)]
#![feature(const_maybe_uninit_write)]
#![feature(const_pin)]
#![feature(const_refs_to_cell)]
#![feature(const_size_of_val)]
#![feature(const_waker)]
#![feature(core_intrinsics)]
#![feature(core_panic)]
#![feature(deprecated_suggestion)]
#![feature(dispatch_from_dyn)]
#![feature(error_generic_member_access)]
#![feature(error_in_core)]
#![feature(exact_size_is_empty)]
#![feature(extend_one)]
#![feature(fmt_internals)]
#![feature(fn_traits)]
#![feature(hasher_prefixfree_extras)]
#![feature(inline_const)]
#![feature(inplace_iteration)]
#![feature(iter_advance_by)]
#![feature(iter_next_chunk)]
#![feature(iter_repeat_n)]
#![feature(layout_for_ptr)]
#![feature(maybe_uninit_slice)]
#![feature(maybe_uninit_uninit_array)]
#![feature(maybe_uninit_uninit_array_transpose)]
#![feature(pattern)]
#![feature(ptr_internals)]
#![feature(ptr_metadata)]
#![feature(ptr_sub_ptr)]
#![feature(receiver_trait)]
#![feature(set_ptr_value)]
#![feature(sized_type_properties)]
#![feature(slice_from_ptr_range)]
#![feature(slice_group_by)]
#![feature(slice_ptr_get)]
#![feature(slice_ptr_len)]
#![feature(slice_range)]
#![feature(std_internals)]
#![feature(str_internals)]
#![feature(strict_provenance)]
#![feature(trusted_fused)]
#![feature(trusted_len)]
#![feature(trusted_random_access)]
#![feature(try_trait_v2)]
#![feature(tuple_trait)]
#![feature(unchecked_math)]
#![feature(unicode_internals)]
#![feature(unsize)]
#![feature(utf8_chunks)]
// tidy-alphabetical-end
//
// Language features:
// tidy-alphabetical-start
#![cfg_attr(not(test), feature(coroutine_trait))]
#![cfg_attr(test, feature(panic_update_hook))]
#![cfg_attr(test, feature(test))]
#![feature(allocator_internals)]
#![feature(allow_internal_unstable)]
#![feature(associated_type_bounds)]
#![feature(c_unwind)]
#![feature(cfg_sanitize)]
#![feature(const_mut_refs)]
#![feature(const_precise_live_drops)]
#![feature(const_ptr_write)]
#![feature(const_trait_impl)]
#![feature(const_try)]
#![feature(dropck_eyepatch)]
#![feature(exclusive_range_pattern)]
#![feature(fundamental)]
#![feature(hashmap_internals)]
#![feature(lang_items)]
#![feature(min_specialization)]
#![feature(multiple_supertrait_upcastable)]
#![feature(negative_impls)]
#![feature(never_type)]
#![feature(pointer_is_aligned)]
#![feature(rustc_allow_const_fn_unstable)]
#![feature(rustc_attrs)]
#![feature(slice_internals)]
#![feature(staged_api)]
#![feature(stmt_expr_attributes)]
#![feature(unboxed_closures)]
#![feature(unsized_fn_params)]
#![feature(with_negative_coherence)]
// 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)]
// Allow testing this library
#[cfg(test)]
#[macro_use]
extern crate std;
#[cfg(test)]
extern crate test;
#[cfg(test)]
mod testing;
// Module with internal macros used by other modules (needs to be included before other modules).
#[cfg(not(no_macros))]
#[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.
#[cfg(not(test))]
pub mod boxed;
#[cfg(test)]
mod boxed {
pub use std::boxed::Box;
}
#[cfg(not(no_borrow))]
pub mod borrow;
pub mod collections;
#[cfg(all(not(no_rc), not(no_sync), not(no_global_oom_handling)))]
pub mod ffi;
#[cfg(not(no_fmt))]
pub mod fmt;
#[cfg(not(no_rc))]
pub mod rc;
pub mod slice;
#[cfg(not(no_str))]
pub mod str;
#[cfg(not(no_string))]
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), target_has_atomic = "ptr"))]
pub mod task;
#[cfg(test)]
mod tests;
pub mod vec;
#[doc(hidden)]
#[unstable(feature = "liballoc_internals", issue = "none", reason = "implementation detail")]
pub mod __export {
pub use core::format_args;
}
#[cfg(test)]
#[allow(dead_code)] // Not used in all configurations
pub(crate) mod test_helpers {
/// Copied from `std::test_helpers::test_rng`, since these tests rely on the
/// seed not being the same for every RNG invocation too.
pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng {
use std::hash::{BuildHasher, Hash, Hasher};
let mut hasher = std::hash::RandomState::new().build_hasher();
std::panic::Location::caller().hash(&mut hasher);
let hc64 = hasher.finish();
let seed_vec =
hc64.to_le_bytes().into_iter().chain(0u8..8).collect::<crate::vec::Vec<u8>>();
let seed: [u8; 16] = seed_vec.as_slice().try_into().unwrap();
rand::SeedableRng::from_seed(seed)
}
}