Struct ockam::compat::boxed::Box

pub struct Box<T, A = Global>(_, _) 
where
    A: Allocator,
    T: ?Sized;

A pointer type for heap allocation.

See the module-level documentation for more.

Implementations

impl<T> Box<T, Global>

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

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>

🔬 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>

🔬 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>>

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

Constructing and pinning of the Box can also be done in two steps: Box::pin(x) does the same as Box::into_pin(Box::new(x)). Consider using into_pin if you already have a Box<T>, or if you want to construct a (pinned) Box in a different way than with Box::new.

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

🔬 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>

🔬 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>

🔬 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, 

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

🔬 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> where
    A: Allocator, 

🔬 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> where
    A: Allocator, 

🔬 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> where
    A: Allocator, 

🔬 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> where
    A: Allocator, 

🔬 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> where
    A: Allocator, 

🔬 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 + Allocator, 

🔬 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.

Constructing and pinning of the Box can also be done in two steps: Box::pin_in(x, alloc) does the same as Box::into_pin(Box::new_in(x, alloc)). Consider using into_pin if you already have a Box<T, A>, or if you want to construct a (pinned) Box in a different way than with Box::new_in.

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

🔬 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.

pub fn into_inner(boxed: Box<T, A>) -> T

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

Consumes the Box, returning the wrapped value.

Examples

#![feature(box_into_inner)]

let c = Box::new(5);

assert_eq!(Box::into_inner(c), 5);

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

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

🔬 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>

🔬 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])

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

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

Constructs a new boxed slice with uninitialized contents. Returns an error if the allocation fails

Examples

#![feature(allocator_api, new_uninit)]

let mut values = Box::<[u32]>::try_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 try_new_zeroed_slice(
    len: usize
) -> Result<Box<[MaybeUninit<T>], Global>, AllocError>

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

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

let values = Box::<[u32]>::try_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, 

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

🔬 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>

🔬 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, 

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

🔬 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)

pub fn write(boxed: Box<MaybeUninit<T>, A>, value: T) -> Box<T, A>

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

Writes the value and converts to Box<T, A>.

This method converts the box similarly to Box::assume_init but writes value into it before conversion thus guaranteeing safety. In some scenarios use of this method may improve performance because the compiler may be able to optimize copying from stack.

Examples

#![feature(new_uninit)]

let big_box = Box::<[usize; 1024]>::new_uninit();

let mut array = [0; 1024];
for (i, place) in array.iter_mut().enumerate() {
    *place = i;
}

// The optimizer may be able to elide this copy, so previous code writes
// to heap directly.
let big_box = Box::write(big_box, array);

for (i, x) in big_box.iter().enumerate() {
    assert_eq!(*x, i);
}

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

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

🔬 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, 

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

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
    A: Allocator,
    T: ?Sized, 

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

🔬 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() 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_in(ptr, System);
}

pub fn into_raw(b: Box<T, A>) -> *mut T

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)

🔬 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

🔬 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 where
    A: 'a, 

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, 

Converts a Box<T> into a Pin<Box<T>>. If T does not implement Unpin, then *boxed will be pinned in memory and unable to be moved.

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

This is also available via From.

Constructing and pinning a Box with Box::into_pin(Box::new(x)) can also be written more concisely using Box::pin(x). This into_pin method is useful if you already have a Box<T>, or you are constructing a (pinned) Box in a different way than with Box::new.

Notes

It’s not recommended that crates add an impl like From<Box<T>> for Pin<T>, as it’ll introduce an ambiguity when calling Pin::from. A demonstration of such a poor impl is shown below.

struct Foo; // A type defined in this crate.
impl From<Box<()>> for Pin<Foo> {
    fn from(_: Box<()>) -> Pin<Foo> {
        Pin::new(Foo)
    }
}

let foo = Box::new(());
let bar = Pin::from(foo);

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

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

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));

pub unsafe fn downcast_unchecked<T>(self) -> Box<T, A> where
    T: Any, 

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

Downcasts the box to a concrete type.

For a safe alternative see downcast.

Examples

#![feature(downcast_unchecked)]

use std::any::Any;

let x: Box<dyn Any> = Box::new(1_usize);

unsafe {
    assert_eq!(*x.downcast_unchecked::<usize>(), 1);
}

Safety

The contained value must be of type T. Calling this method with the incorrect type is undefined behavior.

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

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

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));

pub unsafe fn downcast_unchecked<T>(self) -> Box<T, A> where
    T: Any, 

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

Downcasts the box to a concrete type.

For a safe alternative see downcast.

Examples

#![feature(downcast_unchecked)]

use std::any::Any;

let x: Box<dyn Any + Send> = Box::new(1_usize);

unsafe {
    assert_eq!(*x.downcast_unchecked::<usize>(), 1);
}

Safety

The contained value must be of type T. Calling this method with the incorrect type is undefined behavior.

impl<A> Box<dyn Any + Send + Sync + 'static, A> where
    A: Allocator, 

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

Attempt to downcast the box to a concrete type.

Examples

use std::any::Any;

fn print_if_string(value: Box<dyn Any + Send + Sync>) {
    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));

pub unsafe fn downcast_unchecked<T>(self) -> Box<T, A> where
    T: Any, 

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

Downcasts the box to a concrete type.

For a safe alternative see downcast.

Examples

#![feature(downcast_unchecked)]

use std::any::Any;

let x: Box<dyn Any + Send + Sync> = Box::new(1_usize);

unsafe {
    assert_eq!(*x.downcast_unchecked::<usize>(), 1);
}

Safety

The contained value must be of type T. Calling this method with the incorrect type is undefined behavior.

Trait Implementations

impl<T, A> AsMut<T> for Box<T, A> where
    A: Allocator,
    T: ?Sized, 

fn as_mut(&mut self) -> &mut T

Converts this type into a mutable reference of the (usually inferred) input type.

impl<T, A> AsRef<T> for Box<T, A> where
    A: Allocator,
    T: ?Sized, 

fn as_ref(&self) -> &T

Converts this type into a shared reference of the (usually inferred) input type.

impl<T> AsyncBufRead for Box<T, Global> where
    T: AsyncBufRead + Unpin + ?Sized, 

fn poll_fill_buf(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<&[u8], Error>>

Attempts to return the contents of the internal buffer, filling it with more data from the inner reader if it is empty.

fn consume(self: Pin<&mut Box<T, Global>>, amt: usize)

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to poll_read.

impl<T> AsyncBufRead for Box<T, Global> where
    T: AsyncBufRead + Unpin + ?Sized, 

fn poll_fill_buf(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<&[u8], Error>>

Attempt to return the contents of the internal buffer, filling it with more data from the inner reader if it is empty.

fn consume(self: Pin<&mut Box<T, Global>>, amt: usize)

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to poll_read.

impl<S> AsyncIterator for Box<S, Global> where
    S: AsyncIterator + Unpin + ?Sized, 

type Item = <S as AsyncIterator>::Item

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

The type of items yielded by the async iterator.

fn poll_next(
    self: Pin<&mut Box<S, Global>>,
    cx: &mut Context<'_>
) -> Poll<Option<<Box<S, Global> as AsyncIterator>::Item>>

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

Attempt to pull out the next value of this async iterator, registering the current task for wakeup if the value is not yet available, and returning None if the async iterator is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

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

Returns the bounds on the remaining length of the async iterator.

impl<T> AsyncRead for Box<T, Global> where
    T: AsyncRead + Unpin + ?Sized, 

fn poll_read(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    buf: &mut ReadBuf<'_>
) -> Poll<Result<(), Error>>

Attempts to read from the AsyncRead into buf.

impl<T> AsyncRead for Box<T, Global> where
    T: AsyncRead + Unpin + ?Sized, 

fn poll_read(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    buf: &mut [u8]
) -> Poll<Result<usize, Error>>

Attempt to read from the AsyncRead into buf.

fn poll_read_vectored(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    bufs: &mut [IoSliceMut<'_>]
) -> Poll<Result<usize, Error>>

Attempt to read from the AsyncRead into bufs using vectored IO operations.

impl<T> AsyncSeek for Box<T, Global> where
    T: AsyncSeek + Unpin + ?Sized, 

fn start_seek(
    self: Pin<&mut Box<T, Global>>,
    pos: SeekFrom
) -> Result<(), Error>

Attempts to seek to an offset, in bytes, in a stream.

fn poll_complete(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<u64, Error>>

Waits for a seek operation to complete.

impl<T> AsyncSeek for Box<T, Global> where
    T: AsyncSeek + Unpin + ?Sized, 

fn poll_seek(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    pos: SeekFrom
) -> Poll<Result<u64, Error>>

Attempt to seek to an offset, in bytes, in a stream.

impl<T> AsyncWrite for Box<T, Global> where
    T: AsyncWrite + Unpin + ?Sized, 

fn poll_write(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

Attempt to write bytes from buf into the object.

fn poll_write_vectored(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

Like poll_write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

Determines if this writer has an efficient poll_write_vectored implementation.

fn poll_flush(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

Attempts to flush the object, ensuring that any buffered data reach their destination.

fn poll_shutdown(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

Initiates or attempts to shut down this writer, returning success when the I/O connection has completely shut down.

impl<T> AsyncWrite for Box<T, Global> where
    T: AsyncWrite + Unpin + ?Sized, 

fn poll_write(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    buf: &[u8]
) -> Poll<Result<usize, Error>>

Attempt to write bytes from buf into the object.

fn poll_write_vectored(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>,
    bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>

Attempt to write bytes from bufs into the object using vectored IO operations.

fn poll_flush(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

Attempt to flush the object, ensuring that any buffered data reach their destination.

fn poll_close(
    self: Pin<&mut Box<T, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), Error>>

Attempt to close the object.

impl<T, A> Borrow<T> for Box<T, A> where
    A: Allocator,
    T: ?Sized, 

fn borrow(&self) -> &T

Immutably borrows from an owned value.

impl<T, A> BorrowMut<T> for Box<T, A> where
    A: Allocator,
    T: ?Sized, 

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value.

impl<T> Buf for Box<T, Global> where
    T: Buf + ?Sized, 

fn remaining(&self) -> usize

Returns the number of bytes between the current position and the end of the buffer.

fn chunk(&self) -> &[u8]

Returns a slice starting at the current position and of length between 0 and Buf::remaining(). Note that this can return shorter slice (this allows non-continuous internal representation).

fn chunks_vectored(&'b self, dst: &mut [IoSlice<'b>]) -> usize

Fills dst with potentially multiple slices starting at self’s current position.

fn advance(&mut self, cnt: usize)

Advance the internal cursor of the Buf

fn has_remaining(&self) -> bool

Returns true if there are any more bytes to consume

fn copy_to_slice(&mut self, dst: &mut [u8])

Copies bytes from self into dst.

fn get_u8(&mut self) -> u8

Gets an unsigned 8 bit integer from self.

fn get_i8(&mut self) -> i8

Gets a signed 8 bit integer from self.

fn get_u16(&mut self) -> u16

Gets an unsigned 16 bit integer from self in big-endian byte order.

fn get_u16_le(&mut self) -> u16

Gets an unsigned 16 bit integer from self in little-endian byte order.

fn get_i16(&mut self) -> i16

Gets a signed 16 bit integer from self in big-endian byte order.

fn get_i16_le(&mut self) -> i16

Gets a signed 16 bit integer from self in little-endian byte order.

fn get_u32(&mut self) -> u32

Gets an unsigned 32 bit integer from self in the big-endian byte order.

fn get_u32_le(&mut self) -> u32

Gets an unsigned 32 bit integer from self in the little-endian byte order.

fn get_i32(&mut self) -> i32

Gets a signed 32 bit integer from self in big-endian byte order.

fn get_i32_le(&mut self) -> i32

Gets a signed 32 bit integer from self in little-endian byte order.

fn get_u64(&mut self) -> u64

Gets an unsigned 64 bit integer from self in big-endian byte order.

fn get_u64_le(&mut self) -> u64

Gets an unsigned 64 bit integer from self in little-endian byte order.

fn get_i64(&mut self) -> i64

Gets a signed 64 bit integer from self in big-endian byte order.

fn get_i64_le(&mut self) -> i64

Gets a signed 64 bit integer from self in little-endian byte order.

fn get_uint(&mut self, nbytes: usize) -> u64

Gets an unsigned n-byte integer from self in big-endian byte order.

fn get_uint_le(&mut self, nbytes: usize) -> u64

Gets an unsigned n-byte integer from self in little-endian byte order.

fn get_int(&mut self, nbytes: usize) -> i64

Gets a signed n-byte integer from self in big-endian byte order.

fn get_int_le(&mut self, nbytes: usize) -> i64

Gets a signed n-byte integer from self in little-endian byte order.

fn copy_to_bytes(&mut self, len: usize) -> Bytes

Consumes len bytes inside self and returns new instance of Bytes with this data.

fn get_u128(&mut self) -> u128

Gets an unsigned 128 bit integer from self in big-endian byte order.

fn get_u128_le(&mut self) -> u128

Gets an unsigned 128 bit integer from self in little-endian byte order.

fn get_i128(&mut self) -> i128

Gets a signed 128 bit integer from self in big-endian byte order.

fn get_i128_le(&mut self) -> i128

Gets a signed 128 bit integer from self in little-endian byte order.

fn get_f32(&mut self) -> f32

Gets an IEEE754 single-precision (4 bytes) floating point number from self in big-endian byte order.

fn get_f32_le(&mut self) -> f32

Gets an IEEE754 single-precision (4 bytes) floating point number from self in little-endian byte order.

fn get_f64(&mut self) -> f64

Gets an IEEE754 double-precision (8 bytes) floating point number from self in big-endian byte order.

fn get_f64_le(&mut self) -> f64

Gets an IEEE754 double-precision (8 bytes) floating point number from self in little-endian byte order.

fn take(self, limit: usize) -> Take<Self>

Creates an adaptor which will read at most limit bytes from self.

fn chain<U>(self, next: U) -> Chain<Self, U> where
    U: Buf, 

Creates an adaptor which will chain this buffer with another.

fn reader(self) -> Reader<Self>

Creates an adaptor which implements the Read trait for self.

impl<T> BufMut for Box<T, Global> where
    T: BufMut + ?Sized, 

fn remaining_mut(&self) -> usize

Returns the number of bytes that can be written from the current position until the end of the buffer is reached.

fn chunk_mut(&mut self) -> &mut UninitSlice

Returns a mutable slice starting at the current BufMut position and of length between 0 and BufMut::remaining_mut(). Note that this can be shorter than the whole remainder of the buffer (this allows non-continuous implementation).

unsafe fn advance_mut(&mut self, cnt: usize)

Advance the internal cursor of the BufMut

fn put_slice(&mut self, src: &[u8])

Transfer bytes into self from src and advance the cursor by the number of bytes written.

fn put_u8(&mut self, n: u8)

Writes an unsigned 8 bit integer to self.

fn put_i8(&mut self, n: i8)

Writes a signed 8 bit integer to self.

fn put_u16(&mut self, n: u16)

Writes an unsigned 16 bit integer to self in big-endian byte order.

fn put_u16_le(&mut self, n: u16)

Writes an unsigned 16 bit integer to self in little-endian byte order.

fn put_i16(&mut self, n: i16)

Writes a signed 16 bit integer to self in big-endian byte order.

fn put_i16_le(&mut self, n: i16)

Writes a signed 16 bit integer to self in little-endian byte order.

fn put_u32(&mut self, n: u32)

Writes an unsigned 32 bit integer to self in big-endian byte order.

fn put_u32_le(&mut self, n: u32)

Writes an unsigned 32 bit integer to self in little-endian byte order.

fn put_i32(&mut self, n: i32)

Writes a signed 32 bit integer to self in big-endian byte order.

fn put_i32_le(&mut self, n: i32)

Writes a signed 32 bit integer to self in little-endian byte order.

fn put_u64(&mut self, n: u64)

Writes an unsigned 64 bit integer to self in the big-endian byte order.

fn put_u64_le(&mut self, n: u64)

Writes an unsigned 64 bit integer to self in little-endian byte order.

fn put_i64(&mut self, n: i64)

Writes a signed 64 bit integer to self in the big-endian byte order.

fn put_i64_le(&mut self, n: i64)

Writes a signed 64 bit integer to self in little-endian byte order.

fn has_remaining_mut(&self) -> bool

Returns true if there is space in self for more bytes.

fn put<T>(&mut self, src: T) where
    T: Buf, 

Transfer bytes into self from src and advance the cursor by the number of bytes written.

fn put_bytes(&mut self, val: u8, cnt: usize)

Put cnt bytes val into self.

fn put_u128(&mut self, n: u128)

Writes an unsigned 128 bit integer to self in the big-endian byte order.

fn put_u128_le(&mut self, n: u128)

Writes an unsigned 128 bit integer to self in little-endian byte order.

fn put_i128(&mut self, n: i128)

Writes a signed 128 bit integer to self in the big-endian byte order.

fn put_i128_le(&mut self, n: i128)

Writes a signed 128 bit integer to self in little-endian byte order.

fn put_uint(&mut self, n: u64, nbytes: usize)

Writes an unsigned n-byte integer to self in big-endian byte order.

fn put_uint_le(&mut self, n: u64, nbytes: usize)

Writes an unsigned n-byte integer to self in the little-endian byte order.

fn put_int(&mut self, n: i64, nbytes: usize)

Writes low nbytes of a signed integer to self in big-endian byte order.

fn put_int_le(&mut self, n: i64, nbytes: usize)

Writes low nbytes of a signed integer to self in little-endian byte order.

fn put_f32(&mut self, n: f32)

Writes an IEEE754 single-precision (4 bytes) floating point number to self in big-endian byte order.

fn put_f32_le(&mut self, n: f32)

Writes an IEEE754 single-precision (4 bytes) floating point number to self in little-endian byte order.

fn put_f64(&mut self, n: f64)

Writes an IEEE754 double-precision (8 bytes) floating point number to self in big-endian byte order.

fn put_f64_le(&mut self, n: f64)

Writes an IEEE754 double-precision (8 bytes) floating point number to self in little-endian byte order.

fn limit(self, limit: usize) -> Limit<Self>

Creates an adaptor which can write at most limit bytes to self.

fn writer(self) -> Writer<Self>

Creates an adaptor which implements the Write trait for self.

fn chain_mut<U>(self, next: U) -> Chain<Self, U> where
    U: BufMut, 

Creates an adapter which will chain this buffer with another.

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

fn fill_buf(&mut self) -> Result<&[u8], Error>

Returns the contents of the internal buffer, filling it with more data from the inner reader if it is empty.

fn consume(&mut self, amt: usize)

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to read.

fn read_until(
    &mut self,
    byte: u8,
    buf: &mut Vec<u8, Global>
) -> Result<usize, Error>

Read all bytes into buf until the delimiter byte or EOF is reached.

fn read_line(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until a newline (the 0xA byte) is reached, and append them to the provided buffer. You do not need to clear the buffer before appending.

fn has_data_left(&mut self) -> Result<bool, Error>

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

Check if the underlying Read has any data left to be read.

fn split(self, byte: u8) -> Split<Self>

Returns an iterator over the contents of this reader split on the byte byte.

fn lines(self) -> Lines<Self>

Returns an iterator over the lines of this reader.

impl<T> Clear for Box<T, Global> where
    T: Clear, 

fn clear(&mut self)

Clear all data in self, retaining the allocated capacithy.

impl Clone for Box<Path, Global>

fn clone(&self) -> Box<Path, Global>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Clone for Box<OsStr, Global>

fn clone(&self) -> Box<OsStr, Global>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'clone> Clone for Box<dyn BehaviorHook + 'clone>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'clone> Clone for Box<dyn BehaviorHook + Send + 'clone>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'clone> Clone for Box<dyn BehaviorHook + Sync + 'clone>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'clone> Clone for Box<dyn BehaviorHook + Send + Sync + 'clone>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Clone for Box<str, Global>

fn clone(&self) -> Box<str, Global>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

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

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

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);

fn clone_from(&mut self, source: &Box<T, A>)

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

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Clone for Box<CStr, Global>

fn clone(&self) -> Box<CStr, Global>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'clone, C, M> Clone for Box<dyn SystemHandler<C, M> + 'clone> where
    C: Send + 'static,
    M: Message, 

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'clone, C, M> Clone for Box<dyn SystemHandler<C, M> + Send + 'clone> where
    C: Send + 'static,
    M: Message, 

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'clone, C, M> Clone for Box<dyn SystemHandler<C, M> + Sync + 'clone> where
    C: Send + 'static,
    M: Message, 

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'clone, C, M> Clone for Box<dyn SystemHandler<C, M> + Send + Sync + 'clone> where
    C: Send + 'static,
    M: Message, 

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

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

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'b, C> Decode<'b, C> for Box<Path, Global>

fn decode(d: &mut Decoder<'b>, ctx: &mut C) -> Result<Box<Path, Global>, Error>

Decode a value using the given Decoder.

fn nil() -> Option<Self>

If possible, return a nil value of Self.

impl<'b, C, T> Decode<'b, C> for Box<T, Global> where
    T: Decode<'b, C>, 

fn decode(d: &mut Decoder<'b>, ctx: &mut C) -> Result<Box<T, Global>, Error>

Decode a value using the given Decoder.

fn nil() -> Option<Self>

If possible, return a nil value of Self.

impl<'b, C> Decode<'b, C> for Box<str, Global>

fn decode(d: &mut Decoder<'b>, &mut C) -> Result<Box<str, Global>, Error>

Decode a value using the given Decoder.

fn nil() -> Option<Self>

If possible, return a nil value of Self.

impl Default for Box<OsStr, Global>

fn default() -> Box<OsStr, Global>

Returns the “default value” for a type.

impl Default for Box<str, Global>

fn default() -> Box<str, Global>

Returns the “default value” for a type.

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

fn default() -> Box<[T], Global>

Returns the “default value” for a type.

impl<T> Default for Box<T, Global> where
    T: Default, 

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

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

impl Default for Box<CStr, Global>

fn default() -> Box<CStr, Global>

Returns the “default value” for a type.

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

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

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

fn deref_mut(&mut self) -> &mut T

Mutably dereferences the value.

impl<'de> Deserialize<'de> for Box<Path, Global>

fn deserialize<D>(
    deserializer: D
) -> Result<Box<Path, Global>, <D as Deserializer<'de>>::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<'de, T> Deserialize<'de> for Box<[T], Global> where
    T: Deserialize<'de>, 

fn deserialize<D>(
    deserializer: D
) -> Result<Box<[T], Global>, <D as Deserializer<'de>>::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<'de, T> Deserialize<'de> for Box<T, Global> where
    T: Deserialize<'de>, 

fn deserialize<D>(
    deserializer: D
) -> Result<Box<T, Global>, <D as Deserializer<'de>>::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<'de> Deserialize<'de> for Box<str, Global>

fn deserialize<D>(
    deserializer: D
) -> Result<Box<str, Global>, <D as Deserializer<'de>>::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<'de> Deserialize<'de> for Box<CStr, Global>

fn deserialize<D>(
    deserializer: D
) -> Result<Box<CStr, Global>, <D as Deserializer<'de>>::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

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

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

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

fn next_back(&mut self) -> Option<<I as Iterator>::Item>

Removes and returns an element from the end of the iterator.

fn nth_back(&mut self, n: usize) -> Option<<I as Iterator>::Item>

Returns the nth element from the end of the iterator.

fn advance_back_by(&mut self, n: usize) -> Result<(), usize>

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

Advances the iterator from the back by n elements.

fn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R where
    F: FnMut(B, Self::Item) -> R,
    R: Try<Output = B>, 

This is the reverse version of Iterator::try_fold(): it takes elements starting from the back of the iterator.

fn rfold<B, F>(self, init: B, f: F) -> B where
    F: FnMut(B, Self::Item) -> B, 

An iterator method that reduces the iterator’s elements to a single, final value, starting from the back.

fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item> where
    P: for<'_> FnMut(&Self::Item) -> bool, 

Searches for an element of an iterator from the back that satisfies a predicate.

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

fn drop(&mut self)

Executes the destructor for this type.

impl<C, T> Encode<C> for Box<T, Global> where
    T: Encode<C> + ?Sized, 

fn encode<W>(
    &self,
    e: &mut Encoder<W>,
    ctx: &mut C
) -> Result<(), Error<<W as Write>::Error>> where
    W: Write, 

Encode a value of this type using the given Encoder.

fn is_nil(&self) -> bool

Is this value of Self a nil value?

impl<T> Error for Box<T, Global> where
    T: Error, 

fn description(&self) -> &str

👎 Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎 Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn source(&self) -> Option<&(dyn Error + 'static)>

The lower-level source of this error, if any.

fn backtrace(&self) -> Option<&Backtrace>

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

Returns a stack backtrace, if available, of where this error occurred.

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

fn len(&self) -> usize

Returns the exact length of the iterator.

fn is_empty(&self) -> bool

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

Returns true if the iterator is empty.

impl Extend<Box<str, Global>> for String

fn extend<I>(&mut self, iter: I) where
    I: IntoIterator<Item = Box<str, Global>>, 

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

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

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

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

Reserves capacity in a collection for the given number of additional elements.

impl<S> Filter<S> for Box<dyn Filter<S> + Send + Sync + 'static, Global>

fn enabled(&self, meta: &Metadata<'_>, cx: &Context<'_, S>) -> bool

Returns true if this layer is interested in a span or event with the given Metadata in the current Context, similarly to Subscriber::enabled.

fn callsite_enabled(&self, meta: &'static Metadata<'static>) -> Interest

Returns an Interest indicating whether this layer will always, sometimes, or never be interested in the given Metadata.

fn max_level_hint(&self) -> Option<LevelFilter>

Returns an optional hint of the highest verbosity level that this Filter will enable.

fn on_new_span(&self, attrs: &Attributes<'_>, id: &Id, ctx: Context<'_, S>)

Notifies this filter that a new span was constructed with the given Attributes and Id.

fn on_record(&self, id: &Id, values: &Record<'_>, ctx: Context<'_, S>)

Notifies this filter that a span with the given Id recorded the given values.

fn on_enter(&self, id: &Id, ctx: Context<'_, S>)

Notifies this filter that a span with the given ID was entered.

fn on_exit(&self, id: &Id, ctx: Context<'_, S>)

Notifies this filter that a span with the given ID was exited.

fn on_close(&self, id: Id, ctx: Context<'_, S>)

Notifies this filter that a span with the given ID has been closed.

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

extern "rust-call" fn call(
    &self,
    args: Args
) -> <Box<F, A> as FnOnce<Args>>::Output

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

Performs the call operation.

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

extern "rust-call" fn call_mut(
    &mut self,
    args: Args
) -> <Box<F, A> as FnOnce<Args>>::Output

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

Performs the call operation.

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

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

The returned type after the call operator is used.

extern "rust-call" fn call_once(
    self,
    args: Args
) -> <Box<F, A> as FnOnce<Args>>::Output

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

Performs the call operation.

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

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

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>

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

Converts a &CStr into a Box<CStr>, by copying the contents into a newly allocated Box.

impl<'_> From<&OsStr> for Box<OsStr, Global>

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

Copies the string into a newly allocated Box<OsStr>.

impl<'_> From<&Path> for Box<Path, Global>

fn from(path: &Path) -> Box<Path, Global>

Creates a boxed Path from a reference.

This will allocate and clone path to it.

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

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

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

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

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<str, Global>

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

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>

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

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, 

fn from(s: Box<[T], A>) -> Vec<T, A>

Convert a boxed slice into a vector by transferring ownership of the existing heap allocation.

Examples

let b: Box<[i32]> = vec![1, 2, 3].into_boxed_slice();
assert_eq!(Vec::from(b), vec![1, 2, 3]);

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

fn from(boxed: Box<T, A>) -> Pin<Box<T, A>>

Converts a Box<T> into a Pin<Box<T>>. If T does not implement Unpin, then *boxed will be pinned in memory and unable to be moved.

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

This is also available via Box::into_pin.

Constructing and pinning a Box with <Pin<Box<T>>>::from(Box::new(x)) can also be written more concisely using Box::pin(x). This From implementation is useful if you already have a Box<T>, or you are constructing a (pinned) Box in a different way than with Box::new.

impl<T> From<Box<T, Global>> for Arc<T> where
    T: ?Sized, 

fn from(v: Box<T, Global>) -> Arc<T>

Move a boxed object to a new, reference-counted allocation.

Example

let unique: Box<str> = Box::from("eggplant");
let shared: Arc<str> = Arc::from(unique);
assert_eq!("eggplant", &shared[..]);

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

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

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 String

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

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>

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

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

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

fn from(cow: Cow<'_, [T]>) -> Box<[T], Global>

Converts a Cow<'_, [T]> into a Box<[T]>

When cow is the Cow::Borrowed variant, this conversion allocates on the heap and copies the underlying slice. Otherwise, it will try to reuse the owned Vec’s allocation.

impl<'_> From<Cow<'_, CStr>> for Box<CStr, Global>

fn from(cow: Cow<'_, CStr>) -> Box<CStr, Global>

Converts a Cow<'a, CStr> into a Box<CStr>, by copying the contents if they are borrowed.

impl<'_> From<Cow<'_, OsStr>> for Box<OsStr, Global>

fn from(cow: Cow<'_, OsStr>) -> Box<OsStr, Global>

Converts a Cow<'a, OsStr> into a Box<OsStr>, by copying the contents if they are borrowed.

impl<'_> From<Cow<'_, Path>> for Box<Path, Global>

fn from(cow: Cow<'_, Path>) -> Box<Path, Global>

Creates a boxed Path from a clone-on-write pointer.

Converting from a Cow::Owned does not clone or allocate.

impl<'_> From<Cow<'_, str>> for Box<str, Global>

fn from(cow: Cow<'_, str>) -> Box<str, Global>

Converts a Cow<'_, str> into a Box<str>

When cow is the Cow::Borrowed variant, this conversion allocates on the heap and copies the underlying str. Otherwise, it will try to reuse the owned String’s allocation.

Examples

use std::borrow::Cow;

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

let unboxed = Cow::Owned("hello".to_string());
let boxed: Box<str> = Box::from(unboxed);
println!("{boxed}");

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

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

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 + Send + Sync + 'a, Global>

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

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, 

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

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 + Send + Sync + 'a, Global> where
    E: 'a + Error + Send + Sync, 

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

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>

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

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

impl From<PathBuf> for Box<Path, Global>

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

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 + Send + Sync + 'static, Global>

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

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<dyn Error + 'static, Global>

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

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<str, Global>

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

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>

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

Converts a 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, 

fn from(v: Vec<T, A>) -> Box<[T], A>

Convert a vector into a boxed slice.

If v has excess capacity, its items will be moved into a newly-allocated buffer with exactly the right capacity.

Examples

assert_eq!(Box::from(vec![1, 2, 3]), vec![1, 2, 3].into_boxed_slice());

impl FromIterator<Box<str, Global>> for String

fn from_iter<I>(iter: I) -> String where
    I: IntoIterator<Item = Box<str, Global>>, 

Creates a value from an iterator.

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

fn from_iter<T>(iter: T) -> Box<[I], Global> where
    T: IntoIterator<Item = I>, 

Creates a value from an iterator.

impl<F> FusedFuture for Box<F, Global> where
    F: FusedFuture + Unpin + ?Sized, 

fn is_terminated(&self) -> bool

Returns true if the underlying future should no longer be polled.

impl<S> FusedStream for Box<S, Global> where
    S: FusedStream + Unpin + ?Sized, 

fn is_terminated(&self) -> bool

Returns true if the stream should no longer be polled.

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

type Output = <F as Future>::Output

The type of value produced on completion.

fn poll(
    self: Pin<&mut Box<F, A>>,
    cx: &mut Context<'_>
) -> Poll<<Box<F, A> as Future>::Output>

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available.

impl<G, R, A> Generator<R> for Pin<Box<G, A>> where
    G: Generator<R> + ?Sized,
    A: Allocator + 'static, 

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

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

The type of value this generator yields.

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

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

The type of value this generator returns.

fn resume(
    self: Pin<&mut Pin<Box<G, A>>>,
    arg: R
) -> GeneratorState<<Pin<Box<G, A>> as Generator<R>>::Yield, <Pin<Box<G, A>> as Generator<R>>::Return>

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

Resumes the execution of this generator.

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

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

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

The type of value this generator yields.

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

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

The type of value this generator returns.

fn resume(
    self: Pin<&mut Box<G, A>>,
    arg: R
) -> GeneratorState<<Box<G, A> as Generator<R>>::Yield, <Box<G, A> as Generator<R>>::Return>

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

Resumes the execution of this generator.

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

fn hash<H>(&self, state: &mut H) where
    H: Hasher, 

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<T, A> Hasher for Box<T, A> where
    T: Hasher + ?Sized,
    A: Allocator, 

fn finish(&self) -> u64

Returns the hash value for the values written so far.

fn write(&mut self, bytes: &[u8])

Writes some data into this Hasher.

fn write_u8(&mut self, i: u8)

Writes a single u8 into this hasher.

fn write_u16(&mut self, i: u16)

Writes a single u16 into this hasher.

fn write_u32(&mut self, i: u32)

Writes a single u32 into this hasher.

fn write_u64(&mut self, i: u64)

Writes a single u64 into this hasher.

fn write_u128(&mut self, i: u128)

Writes a single u128 into this hasher.

fn write_usize(&mut self, i: usize)

Writes a single usize into this hasher.

fn write_i8(&mut self, i: i8)

Writes a single i8 into this hasher.

fn write_i16(&mut self, i: i16)

Writes a single i16 into this hasher.

fn write_i32(&mut self, i: i32)

Writes a single i32 into this hasher.

fn write_i64(&mut self, i: i64)

Writes a single i64 into this hasher.

fn write_i128(&mut self, i: i128)

Writes a single i128 into this hasher.

fn write_isize(&mut self, i: isize)

Writes a single isize into this hasher.

fn write_length_prefix(&mut self, len: usize)

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

Writes a length prefix into this hasher, as part of being prefix-free.

fn write_str(&mut self, s: &str)

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

Writes a single str into this hasher.

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

type Item = <I as Iterator>::Item

The type of the elements being iterated over.

fn next(&mut self) -> Option<<I as Iterator>::Item>

Advances the iterator and returns the next value.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the iterator.

fn nth(&mut self, n: usize) -> Option<<I as Iterator>::Item>

Returns the nth element of the iterator.

fn last(self) -> Option<<I as Iterator>::Item>

Consumes the iterator, returning the last element.

fn next_chunk<const N: usize>(
    &mut self
) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>

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

Advances the iterator and returns an array containing the next N values.

fn count(self) -> usize

Consumes the iterator, counting the number of iterations and returning it.

fn advance_by(&mut self, n: usize) -> Result<(), usize>

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

Advances the iterator by n elements.

fn step_by(self, step: usize) -> StepBy<Self>

Creates an iterator starting at the same point, but stepping by the given amount at each iteration.

fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator<Item = Self::Item>, 

Takes two iterators and creates a new iterator over both in sequence.

fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator, 

‘Zips up’ two iterators into a single iterator of pairs.

fn intersperse(self, separator: Self::Item) -> Intersperse<Self> where
    Self::Item: Clone, 

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

Creates a new iterator which places a copy of separator between adjacent items of the original iterator.

fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G> where
    G: FnMut() -> Self::Item, 

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

Creates a new iterator which places an item generated by separator between adjacent items of the original iterator.

fn map<B, F>(self, f: F) -> Map<Self, F> where
    F: FnMut(Self::Item) -> B, 

Takes a closure and creates an iterator which calls that closure on each element.

fn for_each<F>(self, f: F) where
    F: FnMut(Self::Item), 

Calls a closure on each element of an iterator.

fn filter<P>(self, predicate: P) -> Filter<Self, P> where
    P: for<'_> FnMut(&Self::Item) -> bool, 

Creates an iterator which uses a closure to determine if an element should be yielded.

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where
    F: FnMut(Self::Item) -> Option<B>, 

Creates an iterator that both filters and maps.

fn enumerate(self) -> Enumerate<Self>

Creates an iterator which gives the current iteration count as well as the next value.

fn peekable(self) -> Peekable<Self>

Creates an iterator which can use the peek and peek_mut methods to look at the next element of the iterator without consuming it. See their documentation for more information.

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where
    P: for<'_> FnMut(&Self::Item) -> bool, 

Creates an iterator that skips elements based on a predicate.

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where
    P: for<'_> FnMut(&Self::Item) -> bool, 

Creates an iterator that yields elements based on a predicate.

fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P> where
    P: FnMut(Self::Item) -> Option<B>, 

Creates an iterator that both yields elements based on a predicate and maps.

fn skip(self, n: usize) -> Skip<Self>

Creates an iterator that skips the first n elements.

fn take(self, n: usize) -> Take<Self>

Creates an iterator that yields the first n elements, or fewer if the underlying iterator ends sooner.

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where
    F: for<'_> FnMut(&mut St, Self::Item) -> Option<B>, 

An iterator adapter similar to fold that holds internal state and produces a new iterator.

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
    U: IntoIterator,
    F: FnMut(Self::Item) -> U, 

Creates an iterator that works like map, but flattens nested structure.

fn flatten(self) -> Flatten<Self> where
    Self::Item: IntoIterator, 

Creates an iterator that flattens nested structure.

fn fuse(self) -> Fuse<Self>

Creates an iterator which ends after the first None.

fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: for<'_> FnMut(&Self::Item), 

Does something with each element of an iterator, passing the value on.

fn by_ref(&mut self) -> &mut Self

Borrows an iterator, rather than consuming it.

fn collect<B>(self) -> B where
    B: FromIterator<Self::Item>, 

Transforms an iterator into a collection.

fn try_collect<B>(
    &mut self
) -> <<Self::Item as Try>::Residual as Residual<B>>::TryType where
    B: FromIterator<<Self::Item as Try>::Output>,
    Self::Item: Try,
    <Self::Item as Try>::Residual: Residual<B>, 

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

Fallibly transforms an iterator into a collection, short circuiting if a failure is encountered.

fn collect_into<E>(self, collection: &mut E) -> &mut E where
    E: Extend<Self::Item>, 

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

Collects all the items from an iterator into a collection.

fn partition<B, F>(self, f: F) -> (B, B) where
    B: Default + Extend<Self::Item>,
    F: for<'_> FnMut(&Self::Item) -> bool, 

Consumes an iterator, creating two collections from it.

fn partition_in_place<'a, T, P>(self, predicate: P) -> usize where
    T: 'a,
    Self: DoubleEndedIterator<Item = &'a mut T>,
    P: for<'_> FnMut(&T) -> bool, 

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

Reorders the elements of this iterator in-place according to the given predicate, such that all those that return true precede all those that return false. Returns the number of true elements found.

fn is_partitioned<P>(self, predicate: P) -> bool where
    P: FnMut(Self::Item) -> bool, 

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

Checks if the elements of this iterator are partitioned according to the given predicate, such that all those that return true precede all those that return false.

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R where
    F: FnMut(B, Self::Item) -> R,
    R: Try<Output = B>, 

An iterator method that applies a function as long as it returns successfully, producing a single, final value.

fn try_for_each<F, R>(&mut self, f: F) -> R where
    F: FnMut(Self::Item) -> R,
    R: Try<Output = ()>, 

An iterator method that applies a fallible function to each item in the iterator, stopping at the first error and returning that error.

fn fold<B, F>(self, init: B, f: F) -> B where
    F: FnMut(B, Self::Item) -> B, 

Folds every element into an accumulator by applying an operation, returning the final result.

fn reduce<F>(self, f: F) -> Option<Self::Item> where
    F: FnMut(Self::Item, Self::Item) -> Self::Item, 

Reduces the elements to a single one, by repeatedly applying a reducing operation.

fn try_reduce<F, R>(
    &mut self,
    f: F
) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType where
    F: FnMut(Self::Item, Self::Item) -> R,
    R: Try<Output = Self::Item>,
    <R as Try>::Residual: Residual<Option<Self::Item>>, 

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

Reduces the elements to a single one by repeatedly applying a reducing operation. If the closure returns a failure, the failure is propagated back to the caller immediately.

fn all<F>(&mut self, f: F) -> bool where
    F: FnMut(Self::Item) -> bool, 

Tests if every element of the iterator matches a predicate.

fn any<F>(&mut self, f: F) -> bool where
    F: FnMut(Self::Item) -> bool, 

Tests if any element of the iterator matches a predicate.

fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where
    P: for<'_> FnMut(&Self::Item) -> bool, 

Searches for an element of an iterator that satisfies a predicate.

fn find_map<B, F>(&mut self, f: F) -> Option<B> where
    F: FnMut(Self::Item) -> Option<B>, 

Applies function to the elements of iterator and returns the first non-none result.

fn try_find<F, R>(
    &mut self,
    f: F
) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType where
    F: for<'_> FnMut(&Self::Item) -> R,
    R: Try<Output = bool>,
    <R as Try>::Residual: Residual<Option<Self::Item>>, 

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

Applies function to the elements of iterator and returns the first true result or the first error.

fn position<P>(&mut self, predicate: P) -> Option<usize> where
    P: FnMut(Self::Item) -> bool, 

Searches for an element in an iterator, returning its index.

fn rposition<P>(&mut self, predicate: P) -> Option<usize> where
    P: FnMut(Self::Item) -> bool,
    Self: ExactSizeIterator + DoubleEndedIterator, 

Searches for an element in an iterator from the right, returning its index.

fn max(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the maximum element of an iterator.

fn min(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the minimum element of an iterator.

fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: for<'_> FnMut(&Self::Item) -> B, 

Returns the element that gives the maximum value from the specified function.

fn max_by<F>(self, compare: F) -> Option<Self::Item> where
    F: for<'_, '_> FnMut(&Self::Item, &Self::Item) -> Ordering, 

Returns the element that gives the maximum value with respect to the specified comparison function.

fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: for<'_> FnMut(&Self::Item) -> B, 

Returns the element that gives the minimum value from the specified function.

fn min_by<F>(self, compare: F) -> Option<Self::Item> where
    F: for<'_, '_> FnMut(&Self::Item, &Self::Item) -> Ordering, 

Returns the element that gives the minimum value with respect to the specified comparison function.

fn rev(self) -> Rev<Self> where
    Self: DoubleEndedIterator, 

Reverses an iterator’s direction.

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where
    FromA: Default + Extend<A>,
    FromB: Default + Extend<B>,
    Self: Iterator<Item = (A, B)>, 

Converts an iterator of pairs into a pair of containers.

fn copied<'a, T>(self) -> Copied<Self> where
    T: 'a + Copy,
    Self: Iterator<Item = &'a T>, 

Creates an iterator which copies all of its elements.

fn cloned<'a, T>(self) -> Cloned<Self> where
    T: 'a + Clone,
    Self: Iterator<Item = &'a T>, 

Creates an iterator which clones all of its elements.

fn cycle(self) -> Cycle<Self> where
    Self: Clone, 

Repeats an iterator endlessly.

fn sum<S>(self) -> S where
    S: Sum<Self::Item>, 

Sums the elements of an iterator.

fn product<P>(self) -> P where
    P: Product<Self::Item>, 

Iterates over the entire iterator, multiplying all the elements

fn cmp<I>(self, other: I) -> Ordering where
    I: IntoIterator<Item = Self::Item>,
    Self::Item: Ord, 

Lexicographically compares the elements of this Iterator with those of another.

fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering where
    I: IntoIterator,
    F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Ordering, 

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

Lexicographically compares the elements of this Iterator with those of another with respect to the specified comparison function.

fn partial_cmp<I>(self, other: I) -> Option<Ordering> where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Lexicographically compares the elements of this Iterator with those of another.

fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering> where
    I: IntoIterator,
    F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Option<Ordering>, 

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

Lexicographically compares the elements of this Iterator with those of another with respect to the specified comparison function.

fn eq<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are equal to those of another.

fn eq_by<I, F>(self, other: I, eq: F) -> bool where
    I: IntoIterator,
    F: FnMut(Self::Item, <I as IntoIterator>::Item) -> bool, 

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

Determines if the elements of this Iterator are equal to those of another with respect to the specified equality function.

fn ne<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are unequal to those of another.

fn lt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically less than those of another.

fn le<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically less or equal to those of another.

fn gt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically greater than those of another.

fn ge<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another.

fn is_sorted(self) -> bool where
    Self::Item: PartialOrd<Self::Item>, 

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

Checks if the elements of this iterator are sorted.

fn is_sorted_by<F>(self, compare: F) -> bool where
    F: for<'_, '_> FnMut(&Self::Item, &Self::Item) -> Option<Ordering>, 

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

Checks if the elements of this iterator are sorted using the given comparator function.

fn is_sorted_by_key<F, K>(self, f: F) -> bool where
    F: FnMut(Self::Item) -> K,
    K: PartialOrd<K>, 

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

Checks if the elements of this iterator are sorted using the given key extraction function.

impl<S> Layer<S> for Box<dyn Layer<S> + Send + Sync + 'static, Global> where
    S: Subscriber, 

fn on_layer(&mut self, subscriber: &mut S)

Performs late initialization when attaching a Layer to a Subscriber.

fn on_new_span(&self, attrs: &Attributes<'_>, id: &Id, ctx: Context<'_, S>)

Notifies this layer that a new span was constructed with the given Attributes and Id.

fn register_callsite(&self, metadata: &'static Metadata<'static>) -> Interest

Registers a new callsite with this layer, returning whether or not the layer is interested in being notified about the callsite, similarly to Subscriber::register_callsite.

fn enabled(&self, metadata: &Metadata<'_>, ctx: Context<'_, S>) -> bool

Returns true if this layer is interested in a span or event with the given metadata in the current Context, similarly to Subscriber::enabled.

fn on_record(&self, span: &Id, values: &Record<'_>, ctx: Context<'_, S>)

Notifies this layer that a span with the given Id recorded the given values.

fn on_follows_from(&self, span: &Id, follows: &Id, ctx: Context<'_, S>)

Notifies this layer that a span with the ID span recorded that it follows from the span with the ID follows.

fn on_event(&self, event: &Event<'_>, ctx: Context<'_, S>)

Notifies this layer that an event has occurred.

fn on_enter(&self, id: &Id, ctx: Context<'_, S>)

Notifies this layer that a span with the given ID was entered.

fn on_exit(&self, id: &Id, ctx: Context<'_, S>)

Notifies this layer that the span with the given ID was exited.

fn on_close(&self, id: Id, ctx: Context<'_, S>)

Notifies this layer that the span with the given ID has been closed.

fn on_id_change(&self, old: &Id, new: &Id, ctx: Context<'_, S>)

Notifies this layer that a span ID has been cloned, and that the subscriber returned a different ID.

fn and_then<L>(self, layer: L) -> Layered<L, Self, S> where
    L: Layer<S>, 

Composes this layer around the given Layer, returning a Layered struct implementing Layer.

fn with_subscriber(self, inner: S) -> Layered<Self, S, S>

Composes this Layer with the given Subscriber, returning a Layered struct that implements Subscriber.

fn with_filter<F>(self, filter: F) -> Filtered<Self, F, S> where
    F: Filter<S>, 

Combines self with a Filter, returning a Filtered layer.

fn boxed(self) -> Box<dyn Layer<S> + Send + Sync + 'static, Global> where
    Self: 'static + Layer<S> + Send + Sync,
    S: Subscriber, 

Erases the type of this Layer, returning a Boxed dyn Layer trait object.

impl<L, S> Layer<S> for Box<L, Global> where
    L: Layer<S>,
    S: Subscriber, 

fn on_layer(&mut self, subscriber: &mut S)

Performs late initialization when attaching a Layer to a Subscriber.

fn on_new_span(&self, attrs: &Attributes<'_>, id: &Id, ctx: Context<'_, S>)

Notifies this layer that a new span was constructed with the given Attributes and Id.

fn register_callsite(&self, metadata: &'static Metadata<'static>) -> Interest

Registers a new callsite with this layer, returning whether or not the layer is interested in being notified about the callsite, similarly to Subscriber::register_callsite.

fn enabled(&self, metadata: &Metadata<'_>, ctx: Context<'_, S>) -> bool

Returns true if this layer is interested in a span or event with the given metadata in the current Context, similarly to Subscriber::enabled.

fn on_record(&self, span: &Id, values: &Record<'_>, ctx: Context<'_, S>)

Notifies this layer that a span with the given Id recorded the given values.

fn on_follows_from(&self, span: &Id, follows: &Id, ctx: Context<'_, S>)

Notifies this layer that a span with the ID span recorded that it follows from the span with the ID follows.

fn on_event(&self, event: &Event<'_>, ctx: Context<'_, S>)

Notifies this layer that an event has occurred.

fn on_enter(&self, id: &Id, ctx: Context<'_, S>)

Notifies this layer that a span with the given ID was entered.

fn on_exit(&self, id: &Id, ctx: Context<'_, S>)

Notifies this layer that the span with the given ID was exited.

fn on_close(&self, id: Id, ctx: Context<'_, S>)

Notifies this layer that the span with the given ID has been closed.

fn on_id_change(&self, old: &Id, new: &Id, ctx: Context<'_, S>)

Notifies this layer that a span ID has been cloned, and that the subscriber returned a different ID.

fn and_then<L>(self, layer: L) -> Layered<L, Self, S> where
    L: Layer<S>, 

Composes this layer around the given Layer, returning a Layered struct implementing Layer.

fn with_subscriber(self, inner: S) -> Layered<Self, S, S>

Composes this Layer with the given Subscriber, returning a Layered struct that implements Subscriber.

fn with_filter<F>(self, filter: F) -> Filtered<Self, F, S> where
    F: Filter<S>, 

Combines self with a Filter, returning a Filtered layer.

fn boxed(self) -> Box<dyn Layer<S> + Send + Sync + 'static, Global> where
    Self: 'static + Layer<S> + Send + Sync,
    S: Subscriber, 

Erases the type of this Layer, returning a Boxed dyn Layer trait object.

impl<Sp> LocalSpawn for Box<Sp, Global> where
    Sp: LocalSpawn + ?Sized, 

fn spawn_local_obj(
    &self,
    future: LocalFutureObj<'static, ()>
) -> Result<(), SpawnError>

Spawns a future that will be run to completion.

fn status_local(&self) -> Result<(), SpawnError>

Determines whether the executor is able to spawn new tasks.

impl<T> Log for Box<T, Global> where
    T: Log + ?Sized, 

fn enabled(&self, metadata: &Metadata<'_>) -> bool

Determines if a log message with the specified metadata would be logged.

fn log(&self, record: &Record<'_>)

Logs the Record.

fn flush(&self)

Flushes any buffered records.

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

fn cmp(&self, other: &Box<T, A>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

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

fn eq(&self, other: &Box<T, A>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Box<T, A>) -> bool

This method tests for !=.

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

fn partial_cmp(&self, other: &Box<T, A>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Box<T, A>) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Box<T, A>) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn ge(&self, other: &Box<T, A>) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

fn gt(&self, other: &Box<T, A>) -> bool

This method tests greater than (for self and other) and is used by the > operator.

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

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

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

fn read(&mut self, buf: &mut [u8]) -> Result<usize, Error>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> Result<(), Error>

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

Pull some bytes from this source into the specified buffer.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

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

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8, Global>) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Read the exact number of bytes required to fill buf.

fn read_buf_exact(&mut self, buf: &mut ReadBuf<'_>) -> Result<(), Error>

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

Read the exact number of bytes required to fill buf.

fn by_ref(&mut self) -> &mut Self

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R> where
    R: Read, 

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

Creates an adapter which will read at most limit bytes from it.

impl<R> RngCore for Box<R, Global> where
    R: RngCore + ?Sized, 

fn next_u32(&mut self) -> u32

Return the next random u32.

fn next_u64(&mut self) -> u64

Return the next random u64.

fn fill_bytes(&mut self, dest: &mut [u8])

Fill dest with random data.

fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error>

Fill dest entirely with random data.

impl<R> RngCore for Box<R, Global> where
    R: RngCore + ?Sized, 

fn next_u32(&mut self) -> u32

Return the next random u32.

fn next_u64(&mut self) -> u64

Return the next random u64.

fn fill_bytes(&mut self, dest: &mut [u8])

Fill dest with random data.

fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error>

Fill dest entirely with random data.

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

fn seek(&mut self, pos: SeekFrom) -> Result<u64, Error>

Seek to an offset, in bytes, in a stream.

fn stream_position(&mut self) -> Result<u64, Error>

Returns the current seek position from the start of the stream.

fn rewind(&mut self) -> Result<(), Error>

Rewind to the beginning of a stream.

fn stream_len(&mut self) -> Result<u64, Error>

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

Returns the length of this stream (in bytes).

impl<T> Serialize for Box<T, Global> where
    T: Serialize + ?Sized, 

fn serialize<S>(
    &self,
    serializer: S
) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl<S, Item> Sink<Item> for Box<S, Global> where
    S: Sink<Item> + Unpin + ?Sized, 

type Error = <S as Sink<Item>>::Error

The type of value produced by the sink when an error occurs.

fn poll_ready(
    self: Pin<&mut Box<S, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), <Box<S, Global> as Sink<Item>>::Error>>

Attempts to prepare the Sink to receive a value.

fn start_send(
    self: Pin<&mut Box<S, Global>>,
    item: Item
) -> Result<(), <Box<S, Global> as Sink<Item>>::Error>

Begin the process of sending a value to the sink. Each call to this function must be preceded by a successful call to poll_ready which returned Poll::Ready(Ok(())).

fn poll_flush(
    self: Pin<&mut Box<S, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), <Box<S, Global> as Sink<Item>>::Error>>

Flush any remaining output from this sink.

fn poll_close(
    self: Pin<&mut Box<S, Global>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), <Box<S, Global> as Sink<Item>>::Error>>

Flush any remaining output and close this sink, if necessary.

impl<T> Source for Box<T, Global> where
    T: Source + ?Sized, 

fn register(
    &mut self,
    registry: &Registry,
    token: Token,
    interests: Interest
) -> Result<(), Error>

Register self with the given Registry instance.

fn reregister(
    &mut self,
    registry: &Registry,
    token: Token,
    interests: Interest
) -> Result<(), Error>

Re-register self with the given Registry instance.

fn deregister(&mut self, registry: &Registry) -> Result<(), Error>

Deregister self from the given Registry instance.

impl<Sp> Spawn for Box<Sp, Global> where
    Sp: Spawn + ?Sized, 

fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), SpawnError>

Spawns a future that will be run to completion.

fn status(&self) -> Result<(), SpawnError>

Determines whether the executor is able to spawn new tasks.

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

type Item = <S as Stream>::Item

Values yielded by the stream.

fn poll_next(
    self: Pin<&mut Box<S, Global>>,
    cx: &mut Context<'_>
) -> Poll<Option<<Box<S, Global> as Stream>::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.

impl<S> Subscriber for Box<S, Global> where
    S: Subscriber + ?Sized, 

fn register_callsite(&self, metadata: &'static Metadata<'static>) -> Interest

Registers a new callsite with this subscriber, returning whether or not the subscriber is interested in being notified about the callsite.

fn enabled(&self, metadata: &Metadata<'_>) -> bool

Returns true if a span or event with the specified metadata would be recorded.

fn max_level_hint(&self) -> Option<LevelFilter>

Returns the highest verbosity level that this Subscriber will enable, or None, if the subscriber does not implement level-based filtering or chooses not to implement this method.

fn new_span(&self, span: &Attributes<'_>) -> Id

Visit the construction of a new span, returning a new span ID for the span being constructed.

fn record(&self, span: &Id, values: &Record<'_>)

Record a set of values on a span.

fn record_follows_from(&self, span: &Id, follows: &Id)

Adds an indication that span follows from the span with the id follows.

fn event_enabled(&self, event: &Event<'_>) -> bool

Determine if an Event should be recorded.

fn event(&self, event: &Event<'_>)

Records that an Event has occurred.

fn enter(&self, span: &Id)

Records that a span has been entered.

fn exit(&self, span: &Id)

Records that a span has been exited.

fn clone_span(&self, id: &Id) -> Id

Notifies the subscriber that a span ID has been cloned.

fn try_close(&self, id: Id) -> bool

Notifies the subscriber that a span ID has been dropped, and returns true if there are now 0 IDs that refer to that span.

fn drop_span(&self, id: Id)

👎 Deprecated since 0.1.2:

use Subscriber::try_close instead

This method is deprecated.

fn current_span(&self) -> Current

Returns a type representing this subscriber’s view of the current span.

unsafe fn downcast_raw(&self, id: TypeId) -> Option<*const ()>

If self is the same type as the provided TypeId, returns an untyped *const pointer to that type. Otherwise, returns None.

impl<T> TrustPolicy for Box<T, Global> where
    T: TrustPolicy + ?Sized, 

fn check<'life0, 'life1, 'async_trait>(
    &'life0 self,
    trust_info: &'life1 SecureChannelTrustInfo
) -> Pin<Box<dyn Future<Output = Result<bool, Error>> + Send + 'async_trait, Global>> where
    'life0: 'async_trait,
    'life1: 'async_trait,
    Box<T, Global>: 'async_trait, 

fn and<O>(self, other: O) -> AllTrustPolicy<Self, O> where
    O: TrustPolicy, 

fn or<O>(self, other: O) -> AnyTrustPolicy<Self, O> where
    O: TrustPolicy, 

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

fn try_from(
    boxed_slice: Box<[T], Global>
) -> Result<Box<[T; N], Global>, <Box<[T; N], Global> as TryFrom<Box<[T], Global>>>::Error>

Attempts to convert a Box<[T]> into a Box<[T; N]>.

The conversion occurs in-place and does not require a new memory allocation.

Errors

Returns the old Box<[T]> in the Err variant if boxed_slice.len() does not equal N.

type Error = Box<[T], Global>

The type returned in the event of a conversion error.

impl<'a, T> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + Send + 'a, Global> where
    T: 'a, 

fn into_raw(self) -> *mut dyn Future<Output = T> + 'a

Convert an owned instance into a (conceptually owned) fat pointer.

unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer.

impl<'a, T, F> UnsafeFutureObj<'a, T> for Pin<Box<F, Global>> where
    F: 'a + Future<Output = T>, 

fn into_raw(self) -> *mut dyn Future<Output = T> + 'a

Convert an owned instance into a (conceptually owned) fat pointer.

unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer.

impl<'a, T> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + 'a, Global> where
    T: 'a, 

fn into_raw(self) -> *mut dyn Future<Output = T> + 'a

Convert an owned instance into a (conceptually owned) fat pointer.

unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer.

impl<'a, T> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + Send + 'a, Global>> where
    T: 'a, 

fn into_raw(self) -> *mut dyn Future<Output = T> + 'a

Convert an owned instance into a (conceptually owned) fat pointer.

unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer.

impl<'a, T, F> UnsafeFutureObj<'a, T> for Box<F, Global> where
    F: 'a + Future<Output = T>, 

fn into_raw(self) -> *mut dyn Future<Output = T> + 'a

Convert an owned instance into a (conceptually owned) fat pointer.

unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer.

impl<'a, T> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + 'a, Global>> where
    T: 'a, 

fn into_raw(self) -> *mut dyn Future<Output = T> + 'a

Convert an owned instance into a (conceptually owned) fat pointer.

unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer.

impl<T> Value for Box<T, Global> where
    T: Value + ?Sized, 

fn record(&self, key: &Field, visitor: &mut dyn Visit)

Visits this value with the given Visitor.

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

fn write(&mut self, buf: &[u8]) -> Result<usize, Error>

Write a buffer into this writer, returning how many bytes were written.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

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

Determines if this Writer has an efficient write_vectored implementation.

fn flush(&mut self) -> Result<(), Error>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

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

Attempts to write multiple buffers into this writer.

fn by_ref(&mut self) -> &mut Self

Creates a “by reference” adapter for this instance of Write.

impl<Z> Zeroize for Box<[Z], Global> where
    Z: Zeroize, 

fn zeroize(&mut self)

Unlike Vec, Box<[Z]> cannot reallocate, so we can be sure that we are not leaving values on the heap.

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

impl<R> CryptoRng for Box<R, Global> where
    R: CryptoRng + ?Sized, 

impl<R> CryptoRng for Box<R, Global> where
    R: CryptoRng + ?Sized, 

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

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

impl<I, A> FusedIterator for Box<I, A> where
    I: FusedIterator + ?Sized,
    A: Allocator, 

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

impl<Z> ZeroizeOnDrop for Box<[Z], Global> where
    Z: ZeroizeOnDrop,