lib.rs.html -- source
Description: Source to the Rust file `src/liballoc/lib.rs`.
Keywords: rust, rustlang, rust-lang

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    //! # The Rust core allocation and collections library
    //!
    //! This library provides smart pointers and collections for managing
    //! heap-allocated values.
    //!
    //! This library, like libcore, 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`](boxed/index.html) 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`](rc/index.html) 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`](sync/index.html) 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>` is itself
    //! sendable while `Rc<T>` 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.

    #![allow(unused_attributes)]
    #![stable(feature = "alloc", since = "1.36.0")]
    #![doc(html_root_url = "https://doc.rust-lang.org/nightly/",
           issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
           test(no_crate_inject, attr(allow(unused_variables), deny(warnings))))]
    #![no_std]
    #![needs_allocator]

    #![warn(deprecated_in_future)]
    #![warn(missing_docs)]
    #![warn(missing_debug_implementations)]
    #![deny(intra_doc_link_resolution_failure)] // rustdoc is run without -D warnings

    #![deny(rust_2018_idioms)]
    #![allow(explicit_outlives_requirements)]

    #![cfg_attr(not(test), feature(generator_trait))]
    #![cfg_attr(test, feature(test))]

    #![feature(allocator_api)]
    #![feature(allow_internal_unstable)]
    #![feature(arbitrary_self_types)]
    #![feature(box_into_raw_non_null)]
    #![feature(box_patterns)]
    #![feature(box_syntax)]
    #![feature(cfg_target_has_atomic)]
    #![feature(coerce_unsized)]
    #![feature(dispatch_from_dyn)]
    #![feature(core_intrinsics)]
    #![feature(custom_attribute)]
    #![feature(dropck_eyepatch)]
    #![feature(exact_size_is_empty)]
    #![feature(fmt_internals)]
    #![feature(fn_traits)]
    #![feature(fundamental)]
    #![feature(lang_items)]
    #![feature(libc)]
    #![feature(nll)]
    #![feature(optin_builtin_traits)]
    #![feature(pattern)]
    #![feature(ptr_internals)]
    #![feature(ptr_offset_from)]
    #![feature(rustc_attrs)]
    #![feature(receiver_trait)]
    #![feature(specialization)]
    #![feature(staged_api)]
    #![feature(std_internals)]
    #![feature(str_internals)]
    #![feature(trusted_len)]
    #![feature(try_reserve)]
    #![feature(unboxed_closures)]
    #![feature(unicode_internals)]
    #![feature(unsize)]
    #![feature(unsized_locals)]
    #![feature(allocator_internals)]
    #![feature(on_unimplemented)]
    #![feature(rustc_const_unstable)]
    #![feature(const_vec_new)]
    #![feature(slice_partition_dedup)]
    #![feature(maybe_uninit_extra, maybe_uninit_slice, maybe_uninit_array)]
    #![feature(alloc_layout_extra)]
    #![feature(try_trait)]
    #![feature(iter_nth_back)]

    // Allow testing this library

    #[cfg(test)]
    #[macro_use]
    extern crate std;
    #[cfg(test)]
    extern crate test;

    // Module with internal macros used by other modules (needs to be included before other modules).
    #[macro_use]
    mod macros;

    // 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(test)]
    mod boxed_test;
    pub mod collections;
    #[cfg(all(target_has_atomic = "ptr", target_has_atomic = "cas"))]
    pub mod sync;
    pub mod rc;
    pub mod raw_vec;
    pub mod prelude;
    pub mod borrow;
    pub mod fmt;
    pub mod slice;
    pub mod str;
    pub mod string;
    pub mod vec;

    #[cfg(not(test))]
    mod std {
        pub use core::ops; // RangeFull
    }

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