8f85b90ca6
As part of the "arbitrary self types v2" project, we are going to replace the current `Receiver` trait with a new mechanism based on a new, different `Receiver` trait. This PR renames the old trait to get it out the way. Naming is hard. Options considered included: * HardCodedReceiver (because it should only be used for things in the standard library, and hence is sort-of hard coded) * LegacyReceiver * TargetLessReceiver * OldReceiver These are all bad names, but fortunately this will be temporary. Assuming the new mechanism proceeds to stabilization as intended, the legacy trait will be removed altogether. Although we expect this trait to be used only in the standard library, we suspect it may be in use elsehwere, so we're landing this change separately to identify any surprising breakages. It's known that this trait is used within the Rust for Linux project; a patch is in progress to remove their dependency. This is a part of the arbitrary self types v2 project, https://github.com/rust-lang/rfcs/pull/3519 https://github.com/rust-lang/rust/issues/44874 r? @wesleywiser
274 lines
8.8 KiB
Rust
274 lines
8.8 KiB
Rust
//! # The Rust core allocation and collections library
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//!
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//! This library provides smart pointers and collections for managing
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//! heap-allocated values.
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//!
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//! This library, like core, normally doesn’t need to be used directly
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//! since its contents are re-exported in the [`std` crate](../std/index.html).
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//! Crates that use the `#![no_std]` attribute however will typically
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//! not depend on `std`, so they’d use this crate instead.
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//!
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//! ## Boxed values
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//!
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//! The [`Box`] type is a smart pointer type. There can only be one owner of a
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//! [`Box`], and the owner can decide to mutate the contents, which live on the
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//! heap.
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//!
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//! This type can be sent among threads efficiently as the size of a `Box` value
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//! is the same as that of a pointer. Tree-like data structures are often built
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//! with boxes because each node often has only one owner, the parent.
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//!
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//! ## Reference counted pointers
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//!
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//! The [`Rc`] type is a non-threadsafe reference-counted pointer type intended
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//! for sharing memory within a thread. An [`Rc`] pointer wraps a type, `T`, and
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//! only allows access to `&T`, a shared reference.
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//!
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//! This type is useful when inherited mutability (such as using [`Box`]) is too
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//! constraining for an application, and is often paired with the [`Cell`] or
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//! [`RefCell`] types in order to allow mutation.
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//!
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//! ## Atomically reference counted pointers
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//!
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//! The [`Arc`] type is the threadsafe equivalent of the [`Rc`] type. It
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//! provides all the same functionality of [`Rc`], except it requires that the
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//! contained type `T` is shareable. Additionally, [`Arc<T>`][`Arc`] is itself
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//! sendable while [`Rc<T>`][`Rc`] is not.
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//!
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//! This type allows for shared access to the contained data, and is often
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//! paired with synchronization primitives such as mutexes to allow mutation of
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//! shared resources.
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//!
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//! ## Collections
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//!
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//! Implementations of the most common general purpose data structures are
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//! defined in this library. They are re-exported through the
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//! [standard collections library](../std/collections/index.html).
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//!
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//! ## Heap interfaces
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//!
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//! The [`alloc`](alloc/index.html) module defines the low-level interface to the
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//! default global allocator. It is not compatible with the libc allocator API.
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//!
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//! [`Arc`]: sync
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//! [`Box`]: boxed
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//! [`Cell`]: core::cell
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//! [`Rc`]: rc
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//! [`RefCell`]: core::cell
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#![allow(unused_attributes)]
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#![stable(feature = "alloc", since = "1.36.0")]
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#![doc(
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html_playground_url = "https://play.rust-lang.org/",
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issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
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test(no_crate_inject, attr(allow(unused_variables), deny(warnings)))
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)]
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#![doc(cfg_hide(
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not(test),
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not(any(test, bootstrap)),
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no_global_oom_handling,
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not(no_global_oom_handling),
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not(no_rc),
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not(no_sync),
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target_has_atomic = "ptr"
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))]
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#![doc(rust_logo)]
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#![feature(rustdoc_internals)]
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#![no_std]
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#![needs_allocator]
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// Lints:
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#![deny(unsafe_op_in_unsafe_fn)]
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#![deny(fuzzy_provenance_casts)]
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#![warn(deprecated_in_future)]
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#![warn(missing_debug_implementations)]
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#![warn(missing_docs)]
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#![allow(explicit_outlives_requirements)]
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#![warn(multiple_supertrait_upcastable)]
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#![allow(internal_features)]
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#![allow(rustdoc::redundant_explicit_links)]
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#![warn(rustdoc::unescaped_backticks)]
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#![deny(ffi_unwind_calls)]
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//
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// Library features:
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// tidy-alphabetical-start
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#![cfg_attr(not(no_global_oom_handling), feature(const_alloc_error))]
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#![cfg_attr(not(no_global_oom_handling), feature(const_btree_len))]
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#![cfg_attr(test, feature(str_as_str))]
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#![feature(alloc_layout_extra)]
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#![feature(allocator_api)]
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#![feature(array_chunks)]
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#![feature(array_into_iter_constructors)]
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#![feature(array_windows)]
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#![feature(ascii_char)]
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#![feature(assert_matches)]
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#![feature(async_closure)]
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#![feature(async_fn_traits)]
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#![feature(async_iterator)]
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#![feature(box_uninit_write)]
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#![feature(clone_to_uninit)]
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#![feature(coerce_unsized)]
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#![feature(const_align_of_val)]
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#![feature(const_box)]
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#![feature(const_eval_select)]
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#![feature(const_heap)]
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#![feature(const_maybe_uninit_write)]
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#![feature(const_size_of_val)]
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#![feature(const_vec_string_slice)]
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#![feature(core_intrinsics)]
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#![feature(deprecated_suggestion)]
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#![feature(deref_pure_trait)]
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#![feature(dispatch_from_dyn)]
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#![feature(error_generic_member_access)]
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#![feature(exact_size_is_empty)]
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#![feature(extend_one)]
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#![feature(extend_one_unchecked)]
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#![feature(fmt_internals)]
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#![feature(fn_traits)]
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#![feature(hasher_prefixfree_extras)]
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#![feature(inplace_iteration)]
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#![feature(iter_advance_by)]
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#![feature(iter_next_chunk)]
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#![feature(layout_for_ptr)]
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#![feature(legacy_receiver_trait)]
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#![feature(local_waker)]
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#![feature(maybe_uninit_slice)]
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#![feature(maybe_uninit_uninit_array_transpose)]
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#![feature(panic_internals)]
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#![feature(pattern)]
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#![feature(pin_coerce_unsized_trait)]
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#![feature(ptr_internals)]
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#![feature(ptr_metadata)]
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#![feature(ptr_sub_ptr)]
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#![feature(set_ptr_value)]
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#![feature(sized_type_properties)]
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#![feature(slice_from_ptr_range)]
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#![feature(slice_index_methods)]
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#![feature(slice_ptr_get)]
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#![feature(slice_range)]
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#![feature(std_internals)]
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#![feature(str_internals)]
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#![feature(trusted_fused)]
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#![feature(trusted_len)]
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#![feature(trusted_random_access)]
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#![feature(try_trait_v2)]
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#![feature(try_with_capacity)]
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#![feature(tuple_trait)]
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#![feature(unicode_internals)]
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#![feature(unsize)]
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#![feature(unwrap_infallible)]
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#![feature(vec_pop_if)]
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// tidy-alphabetical-end
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//
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// Language features:
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// tidy-alphabetical-start
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#![cfg_attr(bootstrap, feature(strict_provenance))]
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#![cfg_attr(not(bootstrap), feature(strict_provenance_lints))]
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#![cfg_attr(not(test), feature(coroutine_trait))]
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#![cfg_attr(test, feature(panic_update_hook))]
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#![cfg_attr(test, feature(test))]
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#![feature(allocator_internals)]
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#![feature(allow_internal_unstable)]
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#![feature(cfg_sanitize)]
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#![feature(const_precise_live_drops)]
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#![feature(const_try)]
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#![feature(decl_macro)]
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#![feature(dropck_eyepatch)]
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#![feature(fundamental)]
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#![feature(hashmap_internals)]
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#![feature(lang_items)]
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#![feature(min_specialization)]
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#![feature(multiple_supertrait_upcastable)]
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#![feature(negative_impls)]
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#![feature(never_type)]
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#![feature(optimize_attribute)]
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#![feature(rustc_allow_const_fn_unstable)]
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#![feature(rustc_attrs)]
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#![feature(slice_internals)]
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#![feature(staged_api)]
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#![feature(stmt_expr_attributes)]
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#![feature(unboxed_closures)]
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#![feature(unsized_fn_params)]
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#![feature(with_negative_coherence)]
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#![rustc_preserve_ub_checks]
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// tidy-alphabetical-end
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//
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// Rustdoc features:
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#![feature(doc_cfg)]
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#![feature(doc_cfg_hide)]
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// Technically, this is a bug in rustdoc: rustdoc sees the documentation on `#[lang = slice_alloc]`
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// blocks is for `&[T]`, which also has documentation using this feature in `core`, and gets mad
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// that the feature-gate isn't enabled. Ideally, it wouldn't check for the feature gate for docs
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// from other crates, but since this can only appear for lang items, it doesn't seem worth fixing.
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#![feature(intra_doc_pointers)]
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// Allow testing this library
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#[cfg(test)]
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#[macro_use]
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extern crate std;
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#[cfg(test)]
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extern crate test;
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#[cfg(test)]
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mod testing;
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// Module with internal macros used by other modules (needs to be included before other modules).
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#[macro_use]
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mod macros;
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mod raw_vec;
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// Heaps provided for low-level allocation strategies
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pub mod alloc;
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// Primitive types using the heaps above
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// Need to conditionally define the mod from `boxed.rs` to avoid
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// duplicating the lang-items when building in test cfg; but also need
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// to allow code to have `use boxed::Box;` declarations.
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#[cfg(not(test))]
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pub mod boxed;
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#[cfg(test)]
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mod boxed {
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pub use std::boxed::Box;
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}
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pub mod borrow;
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pub mod collections;
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#[cfg(all(not(no_rc), not(no_sync), not(no_global_oom_handling)))]
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pub mod ffi;
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pub mod fmt;
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#[cfg(not(no_rc))]
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pub mod rc;
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pub mod slice;
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pub mod str;
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pub mod string;
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#[cfg(all(not(no_rc), not(no_sync), target_has_atomic = "ptr"))]
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pub mod sync;
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#[cfg(all(not(no_global_oom_handling), not(no_rc), not(no_sync)))]
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pub mod task;
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#[cfg(test)]
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mod tests;
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pub mod vec;
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#[doc(hidden)]
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#[unstable(feature = "liballoc_internals", issue = "none", reason = "implementation detail")]
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pub mod __export {
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pub use core::format_args;
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pub use core::hint::must_use;
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}
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#[cfg(test)]
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#[allow(dead_code)] // Not used in all configurations
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pub(crate) mod test_helpers {
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/// Copied from `std::test_helpers::test_rng`, since these tests rely on the
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/// seed not being the same for every RNG invocation too.
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pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng {
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use std::hash::{BuildHasher, Hash, Hasher};
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let mut hasher = std::hash::RandomState::new().build_hasher();
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std::panic::Location::caller().hash(&mut hasher);
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let hc64 = hasher.finish();
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let seed_vec =
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hc64.to_le_bytes().into_iter().chain(0u8..8).collect::<crate::vec::Vec<u8>>();
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let seed: [u8; 16] = seed_vec.as_slice().try_into().unwrap();
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rand::SeedableRng::from_seed(seed)
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}
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}
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