#![stable(feature = "rust1", since = "1.0.0")]
-use heap::Heap;
use raw_vec::RawVec;
use core::any::Any;
use core::cmp::Ordering;
use core::fmt;
use core::hash::{Hash, Hasher};
-use core::heap::{Alloc, Layout};
use core::iter::FusedIterator;
-use core::marker::{self, Unpin, Unsize};
+use core::marker::{Unpin, Unsize};
use core::mem::{self, Pin};
use core::ops::{CoerceUnsized, Deref, DerefMut, Generator, GeneratorState};
-use core::ops::{BoxPlace, Boxed, InPlace, Place, Placer};
use core::ptr::{self, NonNull, Unique};
use core::convert::From;
use str::from_boxed_utf8_unchecked;
-/// A value that represents the heap. This is the default place that the `box`
-/// keyword allocates into when no place is supplied.
-///
-/// The following two examples are equivalent:
-///
-/// ```
-/// #![feature(box_heap)]
-///
-/// #![feature(box_syntax, placement_in_syntax)]
-/// use std::boxed::HEAP;
-///
-/// fn main() {
-/// let foo: Box<i32> = in HEAP { 5 };
-/// let foo = box 5;
-/// }
-/// ```
-#[unstable(feature = "box_heap",
- reason = "may be renamed; uncertain about custom allocator design",
- issue = "27779")]
-pub const HEAP: ExchangeHeapSingleton = ExchangeHeapSingleton { _force_singleton: () };
-
-/// This the singleton type used solely for `boxed::HEAP`.
-#[unstable(feature = "box_heap",
- reason = "may be renamed; uncertain about custom allocator design",
- issue = "27779")]
-#[allow(missing_debug_implementations)]
-#[derive(Copy, Clone)]
-pub struct ExchangeHeapSingleton {
- _force_singleton: (),
-}
-
/// A pointer type for heap allocation.
///
/// See the [module-level documentation](../../std/boxed/index.html) for more.
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Box<T: ?Sized>(Unique<T>);
-/// `IntermediateBox` represents uninitialized backing storage for `Box`.
-///
-/// FIXME (pnkfelix): Ideally we would just reuse `Box<T>` instead of
-/// introducing a separate `IntermediateBox<T>`; but then you hit
-/// issues when you e.g. attempt to destructure an instance of `Box`,
-/// since it is a lang item and so it gets special handling by the
-/// compiler. Easier just to make this parallel type for now.
-///
-/// FIXME (pnkfelix): Currently the `box` protocol only supports
-/// creating instances of sized types. This IntermediateBox is
-/// designed to be forward-compatible with a future protocol that
-/// supports creating instances of unsized types; that is why the type
-/// parameter has the `?Sized` generalization marker, and is also why
-/// this carries an explicit size. However, it probably does not need
-/// to carry the explicit alignment; that is just a work-around for
-/// the fact that the `align_of` intrinsic currently requires the
-/// input type to be Sized (which I do not think is strictly
-/// necessary).
-#[unstable(feature = "placement_in",
- reason = "placement box design is still being worked out.",
- issue = "27779")]
-#[allow(missing_debug_implementations)]
-pub struct IntermediateBox<T: ?Sized> {
- ptr: *mut u8,
- layout: Layout,
- marker: marker::PhantomData<*mut T>,
-}
-
-#[unstable(feature = "placement_in",
- reason = "placement box design is still being worked out.",
- issue = "27779")]
-unsafe impl<T> Place<T> for IntermediateBox<T> {
- fn pointer(&mut self) -> *mut T {
- self.ptr as *mut T
- }
-}
-
-unsafe fn finalize<T>(b: IntermediateBox<T>) -> Box<T> {
- let p = b.ptr as *mut T;
- mem::forget(b);
- Box::from_raw(p)
-}
-
-fn make_place<T>() -> IntermediateBox<T> {
- let layout = Layout::new::<T>();
-
- let p = if layout.size() == 0 {
- mem::align_of::<T>() as *mut u8
- } else {
- unsafe {
- Heap.alloc(layout.clone()).unwrap_or_else(|err| {
- Heap.oom(err)
- })
- }
- };
-
- IntermediateBox {
- ptr: p,
- layout,
- marker: marker::PhantomData,
- }
-}
-
-#[unstable(feature = "placement_in",
- reason = "placement box design is still being worked out.",
- issue = "27779")]
-impl<T> BoxPlace<T> for IntermediateBox<T> {
- fn make_place() -> IntermediateBox<T> {
- make_place()
- }
-}
-
-#[unstable(feature = "placement_in",
- reason = "placement box design is still being worked out.",
- issue = "27779")]
-impl<T> InPlace<T> for IntermediateBox<T> {
- type Owner = Box<T>;
- unsafe fn finalize(self) -> Box<T> {
- finalize(self)
- }
-}
-
-#[unstable(feature = "placement_new_protocol", issue = "27779")]
-impl<T> Boxed for Box<T> {
- type Data = T;
- type Place = IntermediateBox<T>;
- unsafe fn finalize(b: IntermediateBox<T>) -> Box<T> {
- finalize(b)
- }
-}
-
-#[unstable(feature = "placement_in",
- reason = "placement box design is still being worked out.",
- issue = "27779")]
-impl<T> Placer<T> for ExchangeHeapSingleton {
- type Place = IntermediateBox<T>;
-
- fn make_place(self) -> IntermediateBox<T> {
- make_place()
- }
-}
-
-#[unstable(feature = "placement_in",
- reason = "placement box design is still being worked out.",
- issue = "27779")]
-impl<T: ?Sized> Drop for IntermediateBox<T> {
- fn drop(&mut self) {
- if self.layout.size() > 0 {
- unsafe {
- Heap.dealloc(self.ptr, self.layout.clone())
- }
- }
- }
-}
-
impl<T> Box<T> {
/// Allocates memory on the heap and then places `x` into it.
///
projects / rust.git / blobdiff