Struct sp_std::prelude::Box1.0.0[][src]

#[lang = "owned_box"]pub struct Box<T, A = Global>(_, _)
where
    T: ?Sized,
    A: Allocator
;

A pointer type for heap allocation.

See the module-level documentation for more.

Implementations

impl<T> Box<T, Global>[src]

pub fn new(x: T) -> Box<T, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Allocates memory on the heap and then places x into it.

This doesn't actually allocate if T is zero-sized.

Examples

let five = Box::new(5);

pub fn new_uninit() -> Box<MaybeUninit<T>, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (new_uninit)

Constructs a new box with uninitialized contents.

Examples

#![feature(new_uninit)]

let mut five = Box::<u32>::new_uninit();

let five = unsafe {
    // Deferred initialization:
    five.as_mut_ptr().write(5);

    five.assume_init()
};

assert_eq!(*five, 5)

pub fn new_zeroed() -> Box<MaybeUninit<T>, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (new_uninit)

Constructs a new Box with uninitialized contents, with the memory being filled with 0 bytes.

See MaybeUninit::zeroed for examples of correct and incorrect usage of this method.

Examples

#![feature(new_uninit)]

let zero = Box::<u32>::new_zeroed();
let zero = unsafe { zero.assume_init() };

assert_eq!(*zero, 0)

pub fn pin(x: T) -> Pin<Box<T, Global>>1.33.0[src]

Constructs a new Pin<Box<T>>. If T does not implement Unpin, then x will be pinned in memory and unable to be moved.

pub fn try_new(x: T) -> Result<Box<T, Global>, AllocError>[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Allocates memory on the heap then places x into it, returning an error if the allocation fails

This doesn't actually allocate if T is zero-sized.

Examples

#![feature(allocator_api)]

let five = Box::try_new(5)?;

pub fn try_new_uninit() -> Result<Box<MaybeUninit<T>, Global>, AllocError>[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a new box with uninitialized contents on the heap, returning an error if the allocation fails

Examples

#![feature(allocator_api, new_uninit)]

let mut five = Box::<u32>::try_new_uninit()?;

let five = unsafe {
    // Deferred initialization:
    five.as_mut_ptr().write(5);

    five.assume_init()
};

assert_eq!(*five, 5);

pub fn try_new_zeroed() -> Result<Box<MaybeUninit<T>, Global>, AllocError>[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a new Box with uninitialized contents, with the memory being filled with 0 bytes on the heap

See MaybeUninit::zeroed for examples of correct and incorrect usage of this method.

Examples

#![feature(allocator_api, new_uninit)]

let zero = Box::<u32>::try_new_zeroed()?;
let zero = unsafe { zero.assume_init() };

assert_eq!(*zero, 0);

impl<T, A> Box<T, A> where
    A: Allocator
[src]

pub fn new_in(x: T, alloc: A) -> Box<T, A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Allocates memory in the given allocator then places x into it.

This doesn't actually allocate if T is zero-sized.

Examples

#![feature(allocator_api)]

use std::alloc::System;

let five = Box::new_in(5, System);

pub fn try_new_in(x: T, alloc: A) -> Result<Box<T, A>, AllocError>[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Allocates memory in the given allocator then places x into it, returning an error if the allocation fails

This doesn't actually allocate if T is zero-sized.

Examples

#![feature(allocator_api)]

use std::alloc::System;

let five = Box::try_new_in(5, System)?;

pub fn new_uninit_in(alloc: A) -> Box<MaybeUninit<T>, A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a new box with uninitialized contents in the provided allocator.

Examples

#![feature(allocator_api, new_uninit)]

use std::alloc::System;

let mut five = Box::<u32, _>::new_uninit_in(System);

let five = unsafe {
    // Deferred initialization:
    five.as_mut_ptr().write(5);

    five.assume_init()
};

assert_eq!(*five, 5)

pub fn try_new_uninit_in(alloc: A) -> Result<Box<MaybeUninit<T>, A>, AllocError>[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a new box with uninitialized contents in the provided allocator, returning an error if the allocation fails

Examples

#![feature(allocator_api, new_uninit)]

use std::alloc::System;

let mut five = Box::<u32, _>::try_new_uninit_in(System)?;

let five = unsafe {
    // Deferred initialization:
    five.as_mut_ptr().write(5);

    five.assume_init()
};

assert_eq!(*five, 5);

pub fn new_zeroed_in(alloc: A) -> Box<MaybeUninit<T>, A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a new Box with uninitialized contents, with the memory being filled with 0 bytes in the provided allocator.

See MaybeUninit::zeroed for examples of correct and incorrect usage of this method.

Examples

#![feature(allocator_api, new_uninit)]

use std::alloc::System;

let zero = Box::<u32, _>::new_zeroed_in(System);
let zero = unsafe { zero.assume_init() };

assert_eq!(*zero, 0)

pub fn try_new_zeroed_in(alloc: A) -> Result<Box<MaybeUninit<T>, A>, AllocError>[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a new Box with uninitialized contents, with the memory being filled with 0 bytes in the provided allocator, returning an error if the allocation fails,

See MaybeUninit::zeroed for examples of correct and incorrect usage of this method.

Examples

#![feature(allocator_api, new_uninit)]

use std::alloc::System;

let zero = Box::<u32, _>::try_new_zeroed_in(System)?;
let zero = unsafe { zero.assume_init() };

assert_eq!(*zero, 0);

pub fn pin_in(x: T, alloc: A) -> Pin<Box<T, A>> where
    A: 'static, 
[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a new Pin<Box<T, A>>. If T does not implement Unpin, then x will be pinned in memory and unable to be moved.

pub fn into_boxed_slice(boxed: Box<T, A>) -> Box<[T], A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (box_into_boxed_slice)

Converts a Box<T> into a Box<[T]>

This conversion does not allocate on the heap and happens in place.

impl<T> Box<[T], Global>[src]

pub fn new_uninit_slice(len: usize) -> Box<[MaybeUninit<T>], Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (new_uninit)

Constructs a new boxed slice with uninitialized contents.

Examples

#![feature(new_uninit)]

let mut values = Box::<[u32]>::new_uninit_slice(3);

let values = unsafe {
    // Deferred initialization:
    values[0].as_mut_ptr().write(1);
    values[1].as_mut_ptr().write(2);
    values[2].as_mut_ptr().write(3);

    values.assume_init()
};

assert_eq!(*values, [1, 2, 3])

pub fn new_zeroed_slice(len: usize) -> Box<[MaybeUninit<T>], Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (new_uninit)

Constructs a new boxed slice with uninitialized contents, with the memory being filled with 0 bytes.

See MaybeUninit::zeroed for examples of correct and incorrect usage of this method.

Examples

#![feature(new_uninit)]

let values = Box::<[u32]>::new_zeroed_slice(3);
let values = unsafe { values.assume_init() };

assert_eq!(*values, [0, 0, 0])

impl<T, A> Box<[T], A> where
    A: Allocator
[src]

pub fn new_uninit_slice_in(len: usize, alloc: A) -> Box<[MaybeUninit<T>], A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a new boxed slice with uninitialized contents in the provided allocator.

Examples

#![feature(allocator_api, new_uninit)]

use std::alloc::System;

let mut values = Box::<[u32], _>::new_uninit_slice_in(3, System);

let values = unsafe {
    // Deferred initialization:
    values[0].as_mut_ptr().write(1);
    values[1].as_mut_ptr().write(2);
    values[2].as_mut_ptr().write(3);

    values.assume_init()
};

assert_eq!(*values, [1, 2, 3])

pub fn new_zeroed_slice_in(len: usize, alloc: A) -> Box<[MaybeUninit<T>], A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a new boxed slice with uninitialized contents in the provided allocator, with the memory being filled with 0 bytes.

See MaybeUninit::zeroed for examples of correct and incorrect usage of this method.

Examples

#![feature(allocator_api, new_uninit)]

use std::alloc::System;

let values = Box::<[u32], _>::new_zeroed_slice_in(3, System);
let values = unsafe { values.assume_init() };

assert_eq!(*values, [0, 0, 0])

impl<T, A> Box<MaybeUninit<T>, A> where
    A: Allocator
[src]

pub unsafe fn assume_init(self) -> Box<T, A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (new_uninit)

Converts to Box<T, A>.

Safety

As with MaybeUninit::assume_init, it is up to the caller to guarantee that the value really is in an initialized state. Calling this when the content is not yet fully initialized causes immediate undefined behavior.

Examples

#![feature(new_uninit)]

let mut five = Box::<u32>::new_uninit();

let five: Box<u32> = unsafe {
    // Deferred initialization:
    five.as_mut_ptr().write(5);

    five.assume_init()
};

assert_eq!(*five, 5)

impl<T, A> Box<[MaybeUninit<T>], A> where
    A: Allocator
[src]

pub unsafe fn assume_init(self) -> Box<[T], A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (new_uninit)

Converts to Box<[T], A>.

Safety

As with MaybeUninit::assume_init, it is up to the caller to guarantee that the values really are in an initialized state. Calling this when the content is not yet fully initialized causes immediate undefined behavior.

Examples

#![feature(new_uninit)]

let mut values = Box::<[u32]>::new_uninit_slice(3);

let values = unsafe {
    // Deferred initialization:
    values[0].as_mut_ptr().write(1);
    values[1].as_mut_ptr().write(2);
    values[2].as_mut_ptr().write(3);

    values.assume_init()
};

assert_eq!(*values, [1, 2, 3])

impl<T> Box<T, Global> where
    T: ?Sized
[src]

pub unsafe fn from_raw(raw: *mut T) -> Box<T, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
1.4.0[src]

Constructs a box from a raw pointer.

After calling this function, the raw pointer is owned by the resulting Box. Specifically, the Box destructor will call the destructor of T and free the allocated memory. For this to be safe, the memory must have been allocated in accordance with the memory layout used by Box .

Safety

This function is unsafe because improper use may lead to memory problems. For example, a double-free may occur if the function is called twice on the same raw pointer.

The safety conditions are described in the memory layout section.

Examples

Recreate a Box which was previously converted to a raw pointer using Box::into_raw:

let x = Box::new(5);
let ptr = Box::into_raw(x);
let x = unsafe { Box::from_raw(ptr) };

Manually create a Box from scratch by using the global allocator:

use std::alloc::{alloc, Layout};

unsafe {
    let ptr = alloc(Layout::new::<i32>()) as *mut i32;
    // In general .write is required to avoid attempting to destruct
    // the (uninitialized) previous contents of `ptr`, though for this
    // simple example `*ptr = 5` would have worked as well.
    ptr.write(5);
    let x = Box::from_raw(ptr);
}

impl<T, A> Box<T, A> where
    T: ?Sized,
    A: Allocator
[src]

pub unsafe fn from_raw_in(raw: *mut T, alloc: A) -> Box<T, A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Constructs a box from a raw pointer in the given allocator.

After calling this function, the raw pointer is owned by the resulting Box. Specifically, the Box destructor will call the destructor of T and free the allocated memory. For this to be safe, the memory must have been allocated in accordance with the memory layout used by Box .

Safety

This function is unsafe because improper use may lead to memory problems. For example, a double-free may occur if the function is called twice on the same raw pointer.

Examples

Recreate a Box which was previously converted to a raw pointer using Box::into_raw_with_allocator:

#![feature(allocator_api)]

use std::alloc::System;

let x = Box::new_in(5, System);
let (ptr, alloc) = Box::into_raw_with_allocator(x);
let x = unsafe { Box::from_raw_in(ptr, alloc) };

Manually create a Box from scratch by using the system allocator:

#![feature(allocator_api, slice_ptr_get)]

use std::alloc::{Allocator, Layout, System};

unsafe {
    let ptr = System.allocate(Layout::new::<i32>())?.as_mut_ptr();
    // In general .write is required to avoid attempting to destruct
    // the (uninitialized) previous contents of `ptr`, though for this
    // simple example `*ptr = 5` would have worked as well.
    ptr.write(5);
    let x = Box::from_raw_in(ptr, System);
}

pub fn into_raw(b: Box<T, A>) -> *mut T1.4.0[src]

Consumes the Box, returning a wrapped raw pointer.

The pointer will be properly aligned and non-null.

After calling this function, the caller is responsible for the memory previously managed by the Box. In particular, the caller should properly destroy T and release the memory, taking into account the memory layout used by Box. The easiest way to do this is to convert the raw pointer back into a Box with the Box::from_raw function, allowing the Box destructor to perform the cleanup.

Note: this is an associated function, which means that you have to call it as Box::into_raw(b) instead of b.into_raw(). This is so that there is no conflict with a method on the inner type.

Examples

Converting the raw pointer back into a Box with Box::from_raw for automatic cleanup:

let x = Box::new(String::from("Hello"));
let ptr = Box::into_raw(x);
let x = unsafe { Box::from_raw(ptr) };

Manual cleanup by explicitly running the destructor and deallocating the memory:

use std::alloc::{dealloc, Layout};
use std::ptr;

let x = Box::new(String::from("Hello"));
let p = Box::into_raw(x);
unsafe {
    ptr::drop_in_place(p);
    dealloc(p as *mut u8, Layout::new::<String>());
}

pub fn into_raw_with_allocator(b: Box<T, A>) -> (*mut T, A)[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Consumes the Box, returning a wrapped raw pointer and the allocator.

The pointer will be properly aligned and non-null.

After calling this function, the caller is responsible for the memory previously managed by the Box. In particular, the caller should properly destroy T and release the memory, taking into account the memory layout used by Box. The easiest way to do this is to convert the raw pointer back into a Box with the Box::from_raw_in function, allowing the Box destructor to perform the cleanup.

Note: this is an associated function, which means that you have to call it as Box::into_raw_with_allocator(b) instead of b.into_raw_with_allocator(). This is so that there is no conflict with a method on the inner type.

Examples

Converting the raw pointer back into a Box with Box::from_raw_in for automatic cleanup:

#![feature(allocator_api)]

use std::alloc::System;

let x = Box::new_in(String::from("Hello"), System);
let (ptr, alloc) = Box::into_raw_with_allocator(x);
let x = unsafe { Box::from_raw_in(ptr, alloc) };

Manual cleanup by explicitly running the destructor and deallocating the memory:

#![feature(allocator_api)]

use std::alloc::{Allocator, Layout, System};
use std::ptr::{self, NonNull};

let x = Box::new_in(String::from("Hello"), System);
let (ptr, alloc) = Box::into_raw_with_allocator(x);
unsafe {
    ptr::drop_in_place(ptr);
    let non_null = NonNull::new_unchecked(ptr);
    alloc.deallocate(non_null.cast(), Layout::new::<String>());
}

pub fn allocator(b: &Box<T, A>) -> &A

Notable traits for &'_ mut I

impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

🔬 This is a nightly-only experimental API. (allocator_api)

Returns a reference to the underlying allocator.

Note: this is an associated function, which means that you have to call it as Box::allocator(&b) instead of b.allocator(). This is so that there is no conflict with a method on the inner type.

pub fn leak<'a>(b: Box<T, A>) -> &'a mut T

Notable traits for &'_ mut I

impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
where
    A: 'a, 
1.26.0[src]

Consumes and leaks the Box, returning a mutable reference, &'a mut T. Note that the type T must outlive the chosen lifetime 'a. If the type has only static references, or none at all, then this may be chosen to be 'static.

This function is mainly useful for data that lives for the remainder of the program's life. Dropping the returned reference will cause a memory leak. If this is not acceptable, the reference should first be wrapped with the Box::from_raw function producing a Box. This Box can then be dropped which will properly destroy T and release the allocated memory.

Note: this is an associated function, which means that you have to call it as Box::leak(b) instead of b.leak(). This is so that there is no conflict with a method on the inner type.

Examples

Simple usage:

let x = Box::new(41);
let static_ref: &'static mut usize = Box::leak(x);
*static_ref += 1;
assert_eq!(*static_ref, 42);

Unsized data:

let x = vec![1, 2, 3].into_boxed_slice();
let static_ref = Box::leak(x);
static_ref[0] = 4;
assert_eq!(*static_ref, [4, 2, 3]);

pub fn into_pin(boxed: Box<T, A>) -> Pin<Box<T, A>> where
    A: 'static, 
[src]

🔬 This is a nightly-only experimental API. (box_into_pin)

Converts a Box<T> into a Pin<Box<T>>

This conversion does not allocate on the heap and happens in place.

This is also available via From.

impl<A> Box<dyn Any + 'static, A> where
    A: Allocator
[src]

pub fn downcast<T>(self) -> Result<Box<T, A>, Box<dyn Any + 'static, A>> where
    T: Any
[src]

Attempt to downcast the box to a concrete type.

Examples

use std::any::Any;

fn print_if_string(value: Box<dyn Any>) {
    if let Ok(string) = value.downcast::<String>() {
        println!("String ({}): {}", string.len(), string);
    }
}

let my_string = "Hello World".to_string();
print_if_string(Box::new(my_string));
print_if_string(Box::new(0i8));

impl<A> Box<dyn Any + 'static + Send, A> where
    A: Allocator
[src]

pub fn downcast<T>(self) -> Result<Box<T, A>, Box<dyn Any + 'static + Send, A>> where
    T: Any
[src]

Attempt to downcast the box to a concrete type.

Examples

use std::any::Any;

fn print_if_string(value: Box<dyn Any + Send>) {
    if let Ok(string) = value.downcast::<String>() {
        println!("String ({}): {}", string.len(), string);
    }
}

let my_string = "Hello World".to_string();
print_if_string(Box::new(my_string));
print_if_string(Box::new(0i8));

Trait Implementations

impl<T, A> AsMut<T> for Box<T, A> where
    T: ?Sized,
    A: Allocator
1.5.0[src]

impl<T, A> AsRef<T> for Box<T, A> where
    T: ?Sized,
    A: Allocator
1.5.0[src]

impl<T, A> Borrow<T> for Box<T, A> where
    T: ?Sized,
    A: Allocator
1.1.0[src]

impl<T, A> BorrowMut<T> for Box<T, A> where
    T: ?Sized,
    A: Allocator
1.1.0[src]

impl<B> BufRead for Box<B, Global> where
    B: BufRead + ?Sized
[src]

impl Clone for Box<Path, Global>1.29.0[src]

impl Clone for Box<CStr, Global>1.29.0[src]

impl Clone for Box<OsStr, Global>1.29.0[src]

impl Clone for Box<str, Global>1.3.0[src]

impl<T, A> Clone for Box<[T], A> where
    T: Clone,
    A: Clone + Allocator
1.3.0[src]

impl<T, A> Clone for Box<T, A> where
    T: Clone,
    A: Clone + Allocator
[src]

pub fn clone(&self) -> Box<T, A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Returns a new box with a clone() of this box's contents.

Examples

let x = Box::new(5);
let y = x.clone();

// The value is the same
assert_eq!(x, y);

// But they are unique objects
assert_ne!(&*x as *const i32, &*y as *const i32);

pub fn clone_from(&mut self, source: &Box<T, A>)[src]

Copies source's contents into self without creating a new allocation.

Examples

let x = Box::new(5);
let mut y = Box::new(10);
let yp: *const i32 = &*y;

y.clone_from(&x);

// The value is the same
assert_eq!(x, y);

// And no allocation occurred
assert_eq!(yp, &*y);

impl<T, U, A> CoerceUnsized<Box<U, A>> for Box<T, A> where
    T: Unsize<U> + ?Sized,
    A: Allocator,
    U: ?Sized
[src]

impl<T, A> Debug for Box<T, A> where
    T: Debug + ?Sized,
    A: Allocator
[src]

impl Default for Box<CStr, Global>1.17.0[src]

impl Default for Box<OsStr, Global>1.17.0[src]

impl Default for Box<str, Global>1.17.0[src]

impl<T> Default for Box<T, Global> where
    T: Default
[src]

pub fn default() -> Box<T, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Creates a Box<T>, with the Default value for T.

impl<T> Default for Box<[T], Global>[src]

impl<T, A> Deref for Box<T, A> where
    T: ?Sized,
    A: Allocator
[src]

type Target = T

The resulting type after dereferencing.

impl<T, A> DerefMut for Box<T, A> where
    T: ?Sized,
    A: Allocator
[src]

impl<T, U> DispatchFromDyn<Box<U, Global>> for Box<T, Global> where
    T: Unsize<U> + ?Sized,
    U: ?Sized
[src]

impl<T, A> Display for Box<T, A> where
    T: Display + ?Sized,
    A: Allocator
[src]

impl<I, A> DoubleEndedIterator for Box<I, A> where
    A: Allocator,
    I: DoubleEndedIterator + ?Sized
[src]

impl<T, A> Drop for Box<T, A> where
    T: ?Sized,
    A: Allocator
[src]

impl<T, A> Eq for Box<T, A> where
    T: Eq + ?Sized,
    A: Allocator
[src]

impl<T> Error for Box<T, Global> where
    T: Error
1.8.0[src]

impl<I, A> ExactSizeIterator for Box<I, A> where
    A: Allocator,
    I: ExactSizeIterator + ?Sized
[src]

impl Extend<Box<str, Global>> for String1.45.0[src]

impl<Args, F, A> Fn<Args> for Box<F, A> where
    A: Allocator,
    F: Fn<Args> + ?Sized
1.35.0[src]

impl<Args, F, A> FnMut<Args> for Box<F, A> where
    A: Allocator,
    F: FnMut<Args> + ?Sized
1.35.0[src]

impl<Args, F, A> FnOnce<Args> for Box<F, A> where
    A: Allocator,
    F: FnOnce<Args> + ?Sized
1.35.0[src]

type Output = <F as FnOnce<Args>>::Output

The returned type after the call operator is used.

impl<'_, T> From<&'_ [T]> for Box<[T], Global> where
    T: Copy
1.17.0[src]

pub fn from(slice: &[T]) -> Box<[T], Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a &[T] into a Box<[T]>

This conversion allocates on the heap and performs a copy of slice.

Examples

// create a &[u8] which will be used to create a Box<[u8]>
let slice: &[u8] = &[104, 101, 108, 108, 111];
let boxed_slice: Box<[u8]> = Box::from(slice);

println!("{:?}", boxed_slice);

impl<'_> From<&'_ CStr> for Box<CStr, Global>1.17.0[src]

impl<'_> From<&'_ OsStr> for Box<OsStr, Global>1.17.0[src]

impl<'_> From<&'_ Path> for Box<Path, Global>1.17.0[src]

impl<'a, '_> From<&'_ str> for Box<dyn Error + 'a + Send + Sync, Global>[src]

pub fn from(err: &str) -> Box<dyn Error + 'a + Send + Sync, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a str into a box of dyn Error + Send + Sync.

Examples

use std::error::Error;
use std::mem;

let a_str_error = "a str error";
let a_boxed_error = Box::<dyn Error + Send + Sync>::from(a_str_error);
assert!(
    mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))

impl<'_> From<&'_ str> for Box<dyn Error + 'static, Global>1.6.0[src]

pub fn from(err: &str) -> Box<dyn Error + 'static, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a str into a box of dyn Error.

Examples

use std::error::Error;
use std::mem;

let a_str_error = "a str error";
let a_boxed_error = Box::<dyn Error>::from(a_str_error);
assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))

impl<'_> From<&'_ str> for Box<str, Global>1.17.0[src]

pub fn from(s: &str) -> Box<str, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a &str into a Box<str>

This conversion allocates on the heap and performs a copy of s.

Examples

let boxed: Box<str> = Box::from("hello");
println!("{}", boxed);

impl<T, const N: usize> From<[T; N]> for Box<[T], Global>1.45.0[src]

pub fn from(array: [T; N]) -> Box<[T], Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a [T; N] into a Box<[T]>

This conversion moves the array to newly heap-allocated memory.

Examples

let boxed: Box<[u8]> = Box::from([4, 2]);
println!("{:?}", boxed);

impl<T, A> From<Box<[T], A>> for Vec<T, A> where
    A: Allocator
1.18.0[src]

impl From<Box<CStr, Global>> for CString1.18.0[src]

pub fn from(s: Box<CStr, Global>) -> CString[src]

Converts a Box<CStr> into a CString without copying or allocating.

impl From<Box<OsStr, Global>> for OsString1.18.0[src]

pub fn from(boxed: Box<OsStr, Global>) -> OsString[src]

Converts a Box<OsStr> into a OsString without copying or allocating.

impl From<Box<Path, Global>> for PathBuf1.18.0[src]

pub fn from(boxed: Box<Path, Global>) -> PathBuf[src]

Converts a Box<Path> into a PathBuf

This conversion does not allocate or copy memory.

impl<T, A> From<Box<T, A>> for Pin<Box<T, A>> where
    T: ?Sized,
    A: Allocator + 'static, 
1.33.0[src]

pub fn from(boxed: Box<T, A>) -> Pin<Box<T, A>>[src]

Converts a Box<T> into a Pin<Box<T>>

This conversion does not allocate on the heap and happens in place.

impl<T> From<Box<T, Global>> for Arc<T> where
    T: ?Sized
1.21.0[src]

impl<T> From<Box<T, Global>> for Rc<T> where
    T: ?Sized
1.21.0[src]

impl<A> From<Box<str, A>> for Box<[u8], A> where
    A: Allocator
1.19.0[src]

pub fn from(s: Box<str, A>) -> Box<[u8], A>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a Box<str> into a Box<[u8]>

This conversion does not allocate on the heap and happens in place.

Examples

// create a Box<str> which will be used to create a Box<[u8]>
let boxed: Box<str> = Box::from("hello");
let boxed_str: Box<[u8]> = Box::from(boxed);

// create a &[u8] which will be used to create a Box<[u8]>
let slice: &[u8] = &[104, 101, 108, 108, 111];
let boxed_slice = Box::from(slice);

assert_eq!(boxed_slice, boxed_str);

impl From<Box<str, Global>> for String1.18.0[src]

pub fn from(s: Box<str, Global>) -> String[src]

Converts the given boxed str slice to a String. It is notable that the str slice is owned.

Examples

Basic usage:

let s1: String = String::from("hello world");
let s2: Box<str> = s1.into_boxed_str();
let s3: String = String::from(s2);

assert_eq!("hello world", s3)

impl From<CString> for Box<CStr, Global>1.20.0[src]

pub fn from(s: CString) -> Box<CStr, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a CString into a Box<CStr> without copying or allocating.

impl<'_, T> From<Cow<'_, [T]>> for Box<[T], Global> where
    T: Copy
1.45.0[src]

impl<'_> From<Cow<'_, CStr>> for Box<CStr, Global>1.45.0[src]

impl<'_> From<Cow<'_, OsStr>> for Box<OsStr, Global>1.45.0[src]

impl<'_> From<Cow<'_, Path>> for Box<Path, Global>1.45.0[src]

impl<'_> From<Cow<'_, str>> for Box<str, Global>1.45.0[src]

impl<'a> From<Cow<'a, str>> for Box<dyn Error + 'static, Global>1.22.0[src]

pub fn from(err: Cow<'a, str>) -> Box<dyn Error + 'static, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a Cow into a box of dyn Error.

Examples

use std::error::Error;
use std::mem;
use std::borrow::Cow;

let a_cow_str_error = Cow::from("a str error");
let a_boxed_error = Box::<dyn Error>::from(a_cow_str_error);
assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))

impl<'a, 'b> From<Cow<'b, str>> for Box<dyn Error + 'a + Send + Sync, Global>1.22.0[src]

pub fn from(err: Cow<'b, str>) -> Box<dyn Error + 'a + Send + Sync, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a Cow into a box of dyn Error + Send + Sync.

Examples

use std::error::Error;
use std::mem;
use std::borrow::Cow;

let a_cow_str_error = Cow::from("a str error");
let a_boxed_error = Box::<dyn Error + Send + Sync>::from(a_cow_str_error);
assert!(
    mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))

impl<'a, E> From<E> for Box<dyn Error + 'a, Global> where
    E: 'a + Error
[src]

pub fn from(err: E) -> Box<dyn Error + 'a, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a type of Error into a box of dyn Error.

Examples

use std::error::Error;
use std::fmt;
use std::mem;

#[derive(Debug)]
struct AnError;

impl fmt::Display for AnError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f , "An error")
    }
}

impl Error for AnError {}

let an_error = AnError;
assert!(0 == mem::size_of_val(&an_error));
let a_boxed_error = Box::<dyn Error>::from(an_error);
assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))

impl<'a, E> From<E> for Box<dyn Error + 'a + Send + Sync, Global> where
    E: 'a + Error + Send + Sync
[src]

pub fn from(err: E) -> Box<dyn Error + 'a + Send + Sync, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a type of Error + Send + Sync into a box of dyn Error + Send + Sync.

Examples

use std::error::Error;
use std::fmt;
use std::mem;

#[derive(Debug)]
struct AnError;

impl fmt::Display for AnError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f , "An error")
    }
}

impl Error for AnError {}

unsafe impl Send for AnError {}

unsafe impl Sync for AnError {}

let an_error = AnError;
assert!(0 == mem::size_of_val(&an_error));
let a_boxed_error = Box::<dyn Error + Send + Sync>::from(an_error);
assert!(
    mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))

impl From<OsString> for Box<OsStr, Global>1.20.0[src]

pub fn from(s: OsString) -> Box<OsStr, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a OsString into a Box<OsStr> without copying or allocating.

impl From<PathBuf> for Box<Path, Global>1.20.0[src]

pub fn from(p: PathBuf) -> Box<Path, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a PathBuf into a Box<Path>

This conversion currently should not allocate memory, but this behavior is not guaranteed on all platforms or in all future versions.

impl From<String> for Box<dyn Error + 'static, Global>1.6.0[src]

pub fn from(str_err: String) -> Box<dyn Error + 'static, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a String into a box of dyn Error.

Examples

use std::error::Error;
use std::mem;

let a_string_error = "a string error".to_string();
let a_boxed_error = Box::<dyn Error>::from(a_string_error);
assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))

impl From<String> for Box<dyn Error + 'static + Send + Sync, Global>[src]

pub fn from(err: String) -> Box<dyn Error + 'static + Send + Sync, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a String into a box of dyn Error + Send + Sync.

Examples

use std::error::Error;
use std::mem;

let a_string_error = "a string error".to_string();
let a_boxed_error = Box::<dyn Error + Send + Sync>::from(a_string_error);
assert!(
    mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))

impl From<String> for Box<str, Global>1.20.0[src]

pub fn from(s: String) -> Box<str, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts the given String to a boxed str slice that is owned.

Examples

Basic usage:

let s1: String = String::from("hello world");
let s2: Box<str> = Box::from(s1);
let s3: String = String::from(s2);

assert_eq!("hello world", s3)

impl<T> From<T> for Box<T, Global>1.6.0[src]

pub fn from(t: T) -> Box<T, Global>

Notable traits for Box<R, Global>

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[src]

Converts a generic type T into a Box<T>

The conversion allocates on the heap and moves t from the stack into it.

Examples

let x = 5;
let boxed = Box::new(5);

assert_eq!(Box::from(x), boxed);

impl<T, A> From<Vec<T, A>> for Box<[T], A> where
    A: Allocator
1.20.0[src]

impl FromIterator<Box<str, Global>> for String1.45.0[src]

impl<I> FromIterator<I> for Box<[I], Global>1.32.0[src]

impl<I, A> FusedIterator for Box<I, A> where
    A: Allocator,
    I: FusedIterator + ?Sized
1.26.0[src]

impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
1.36.0[src]

type Output = <F as Future>::Output

The type of value produced on completion.

impl<G, R, A> Generator<R> for Box<G, A> where
    A: Allocator + 'static,
    G: Unpin + Generator<R> + ?Sized
[src]

type Yield = <G as Generator<R>>::Yield

🔬 This is a nightly-only experimental API. (generator_trait)

The type of value this generator yields. Read more

type Return = <G as Generator<R>>::Return

🔬 This is a nightly-only experimental API. (generator_trait)

The type of value this generator returns. Read more

impl<T, A> Hash for Box<T, A> where
    T: Hash + ?Sized,
    A: Allocator
[src]

impl<T, A> Hasher for Box<T, A> where
    T: Hasher + ?Sized,
    A: Allocator
1.22.0[src]

impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
[src]

type Item = <I as Iterator>::Item

The type of the elements being iterated over.

impl<T, A> Ord for Box<T, A> where
    T: Ord + ?Sized,
    A: Allocator
[src]

impl<T, A> PartialEq<Box<T, A>> for Box<T, A> where
    T: PartialEq<T> + ?Sized,
    A: Allocator
[src]

impl<T, A> PartialOrd<Box<T, A>> for Box<T, A> where
    T: PartialOrd<T> + ?Sized,
    A: Allocator
[src]

impl<T, A> Pointer for Box<T, A> where
    T: ?Sized,
    A: Allocator
[src]

impl<R> Read for Box<R, Global> where
    R: Read + ?Sized
[src]

impl<S> Seek for Box<S, Global> where
    S: Seek + ?Sized
[src]

impl<S> Stream for Box<S, Global> where
    S: Unpin + Stream + ?Sized
[src]

type Item = <S as Stream>::Item

🔬 This is a nightly-only experimental API. (async_stream)

The type of items yielded by the stream.

impl<T, const N: usize> TryFrom<Box<[T], Global>> for Box<[T; N], Global>1.43.0[src]

type Error = Box<[T], Global>

The type returned in the event of a conversion error.

impl<T, A> Unpin for Box<T, A> where
    T: ?Sized,
    A: Allocator + 'static, 
1.33.0[src]

impl<W> Write for Box<W, Global> where
    W: Write + ?Sized
[src]

Auto Trait Implementations

impl<T: ?Sized, A> RefUnwindSafe for Box<T, A> where
    A: RefUnwindSafe,
    T: RefUnwindSafe
[src]

impl<T: ?Sized, A> Send for Box<T, A> where
    A: Send,
    T: Send
[src]

impl<T: ?Sized, A> Sync for Box<T, A> where
    A: Sync,
    T: Sync
[src]

impl<T: ?Sized, A> UnwindSafe for Box<T, A> where
    A: UnwindSafe,
    T: UnwindSafe
[src]

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> From<!> for T[src]

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<F> IntoFuture for F where
    F: Future
[src]

type Output = <F as Future>::Output

🔬 This is a nightly-only experimental API. (into_future)

The output that the future will produce on completion.

type Future = F

🔬 This is a nightly-only experimental API. (into_future)

Which kind of future are we turning this into?

impl<I> IntoIterator for I where
    I: Iterator
[src]

type Item = <I as Iterator>::Item

The type of the elements being iterated over.

type IntoIter = I

Which kind of iterator are we turning this into?

impl<'a, F> Pattern<'a> for F where
    F: FnMut(char) -> bool
[src]

type Searcher = CharPredicateSearcher<'a, F>

🔬 This is a nightly-only experimental API. (pattern)

API not fully fleshed out and ready to be stabilized

Associated searcher for this pattern

impl<T> ToOwned for T where
    T: Clone
[src]

type Owned = T

The resulting type after obtaining ownership.

impl<T> ToString for T where
    T: Display + ?Sized
[src]

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.