src/liballoc/lib.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! # The Rust core allocation library
  12 //!
  13 //! This is the lowest level library through which allocation in Rust can be
  14 //! performed.
  15 //!
  16 //! This library, like libcore, is not intended for general usage, but rather as
  17 //! a building block of other libraries. The types and interfaces in this
  18 //! library are reexported through the [standard library](../std/index.html),
  19 //! and should not be used through this library.
  20 //!
  21 //! Currently, there are four major definitions in this library.
  22 //!
  23 //! ## Boxed values
  24 //!
  25 //! The [`Box`](boxed/index.html) type is a smart pointer type. There can
  26 //! only be one owner of a `Box`, and the owner can decide to mutate the
  27 //! contents, which live on the heap.
  28 //!
  29 //! This type can be sent among threads efficiently as the size of a `Box` value
  30 //! is the same as that of a pointer. Tree-like data structures are often built
  31 //! with boxes because each node often has only one owner, the parent.
  32 //!
  33 //! ## Reference counted pointers
  34 //!
  35 //! The [`Rc`](rc/index.html) type is a non-threadsafe reference-counted pointer
  36 //! type intended for sharing memory within a thread. An `Rc` pointer wraps a
  37 //! type, `T`, and only allows access to `&T`, a shared reference.
  38 //!
  39 //! This type is useful when inherited mutability (such as using `Box`) is too
  40 //! constraining for an application, and is often paired with the `Cell` or
  41 //! `RefCell` types in order to allow mutation.
  42 //!
  43 //! ## Atomically reference counted pointers
  44 //!
  45 //! The [`Arc`](arc/index.html) type is the threadsafe equivalent of the `Rc`
  46 //! type. It provides all the same functionality of `Rc`, except it requires
  47 //! that the contained type `T` is shareable. Additionally, `Arc<T>` is itself
  48 //! sendable while `Rc<T>` is not.
  49 //!
  50 //! This types allows for shared access to the contained data, and is often
  51 //! paired with synchronization primitives such as mutexes to allow mutation of
  52 //! shared resources.
  53 //!
  54 //! ## Heap interfaces
  55 //!
  56 //! The [`heap`](heap/index.html) module defines the low-level interface to the
  57 //! default global allocator. It is not compatible with the libc allocator API.
  58
  59 #![crate_name = "alloc"]
  60 #![crate_type = "rlib"]
  61 #![allow(unused_attributes)]
  62 #![unstable(feature = "alloc",
  63             reason = "this library is unlikely to be stabilized in its current \
  64                       form or name",
  65             issue = "27783")]
  66 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  67        html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
  68        html_root_url = "https://doc.rust-lang.org/nightly/",
  69        issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
  70        test(no_crate_inject, attr(allow(unused_variables), deny(warnings))))]
  71 #![no_std]
  72 #![needs_allocator]
  73 #![cfg_attr(not(stage0), deny(warnings))]
  74
  75 #![feature(allocator)]
  76 #![feature(box_syntax)]
  77 #![feature(coerce_unsized)]
  78 #![feature(const_fn)]
  79 #![feature(core_intrinsics)]
  80 #![feature(custom_attribute)]
  81 #![feature(dropck_parametricity)]
  82 #![feature(fundamental)]
  83 #![feature(lang_items)]
  84 #![feature(needs_allocator)]
  85 #![feature(optin_builtin_traits)]
  86 #![feature(placement_in_syntax)]
  87 #![feature(shared)]
  88 #![feature(staged_api)]
  89 #![feature(unboxed_closures)]
  90 #![feature(unique)]
  91 #![feature(unsafe_no_drop_flag, filling_drop)]
  92 #![feature(unsize)]
  93 #![feature(extended_compare_and_swap)]
  94
  95 #![cfg_attr(not(test), feature(raw, fn_traits, placement_new_protocol))]
  96 #![cfg_attr(test, feature(test, box_heap))]
  97
  98 // Allow testing this library
  99
 100 #[cfg(test)]
 101 #[macro_use]
 102 extern crate std;
 103
 104 // Heaps provided for low-level allocation strategies
 105
 106 pub mod heap;
 107
 108 // Primitive types using the heaps above
 109
 110 // Need to conditionally define the mod from `boxed.rs` to avoid
 111 // duplicating the lang-items when building in test cfg; but also need
 112 // to allow code to have `use boxed::HEAP;`
 113 // and `use boxed::Box;` declarations.
 114 #[cfg(not(test))]
 115 pub mod boxed;
 116 #[cfg(test)]
 117 mod boxed {
 118     pub use std::boxed::{Box, HEAP};
 119 }
 120 #[cfg(test)]
 121 mod boxed_test;
 122 pub mod arc;
 123 pub mod rc;
 124 pub mod raw_vec;
 125 pub mod oom;
 126
 127 pub use oom::oom;