Struct gstd::prelude::Box

1.0.0 · source ·
pub struct Box<T, A = Global>(/* private fields */)
where
    A: Allocator,
    T: ?Sized;
Expand description

A pointer type that uniquely owns a heap allocation of type T.

See the module-level documentation for more.

Implementations§

source§

impl<T> Box<T>

1.0.0 · source

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

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);
source

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

🔬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)
source

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

🔬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)
1.33.0 · source

pub fn pin(x: T) -> Pin<Box<T>>

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.

source

pub fn try_new(x: T) -> Result<Box<T>, 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)?;
source

pub fn try_new_uninit() -> Result<Box<MaybeUninit<T>>, 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);
source

pub fn try_new_zeroed() -> Result<Box<MaybeUninit<T>>, 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);
source§

impl<T, A> Box<T, A>
where A: Allocator,

source

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);
source

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)?;
source

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)
source

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);
source

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)
source

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);
source

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.

source

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.

source

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);
source§

impl<T> Box<[T]>

source

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

🔬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])
source

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

🔬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])
source

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

pub fn try_new_zeroed_slice( len: usize, ) -> Result<Box<[MaybeUninit<T>]>, 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]);
source§

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

source

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])
source

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])
source

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

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

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

§Examples
#![feature(allocator_api, new_uninit)]

use std::alloc::System;

let mut values = Box::<[u32], _>::try_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]);
source

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

🔬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. 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)]

use std::alloc::System;

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

assert_eq!(*values, [0, 0, 0]);
source§

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

source

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)
source

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);
}
source§

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

source

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])
source§

impl<T> Box<T>
where T: ?Sized,

1.4.0 · source

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

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);
}
source§

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

source

pub const 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);
}
1.4.0 · source

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

Note: This is equivalent to the following:

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

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>());
}
source

pub const 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.

1.26.0 · source

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]);
1.63.0 (const: unstable) · source

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);
source§

impl<A> Box<dyn Any, A>
where A: Allocator,

1.0.0 · source

pub fn downcast<T>(self) -> Result<Box<T, A>, Box<dyn Any, A>>
where T: Any,

Attempts 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));
source

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.

source§

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

1.0.0 · source

pub fn downcast<T>(self) -> Result<Box<T, A>, Box<dyn Any + Send, A>>
where T: Any,

Attempts 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));
source

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.

source§

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

1.51.0 · source

pub fn downcast<T>(self) -> Result<Box<T, A>, Box<dyn Any + Send + Sync, A>>
where T: Any,

Attempts 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));
source

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§

1.5.0 · source§

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

source§

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

Converts this type into a mutable reference of the (usually inferred) input type.
1.5.0 · source§

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

source§

fn as_ref(&self) -> &T

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

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

source§

extern "rust-call" fn async_call( &self, args: Args, ) -> <Box<F, A> as AsyncFnMut<Args>>::CallRefFuture<'_>

🔬This is a nightly-only experimental API. (async_fn_traits)
Call the AsyncFn, returning a future which may borrow from the called closure.
source§

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

§

type CallRefFuture<'a> = <F as AsyncFnMut<Args>>::CallRefFuture<'a> where Box<F, A>: 'a

🔬This is a nightly-only experimental API. (async_fn_traits)
source§

extern "rust-call" fn async_call_mut( &mut self, args: Args, ) -> <Box<F, A> as AsyncFnMut<Args>>::CallRefFuture<'_>

🔬This is a nightly-only experimental API. (async_fn_traits)
Call the AsyncFnMut, returning a future which may borrow from the called closure.
source§

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

§

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

🔬This is a nightly-only experimental API. (async_fn_traits)
Output type of the called closure’s future.
§

type CallOnceFuture = <F as AsyncFnOnce<Args>>::CallOnceFuture

🔬This is a nightly-only experimental API. (async_fn_traits)
Future returned by AsyncFnOnce::async_call_once.
source§

extern "rust-call" fn async_call_once( self, args: Args, ) -> <Box<F, A> as AsyncFnOnce<Args>>::CallOnceFuture

🔬This is a nightly-only experimental API. (async_fn_traits)
Call the AsyncFnOnce, returning a future which may move out of the called closure.
source§

impl<S> AsyncIterator for Box<S>
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.
source§

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

🔬This is a nightly-only experimental API. (async_iterator)
Attempts 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. Read more
source§

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. Read more
1.1.0 · source§

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

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
1.1.0 · source§

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

source§

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

Mutably borrows from an owned value. Read more
1.3.0 · source§

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

source§

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

Copies source’s contents into self without creating a new allocation, so long as the two are of the same length.

§Examples
let x = Box::new([5, 6, 7]);
let mut y = Box::new([8, 9, 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);
source§

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

Returns a copy of the value. Read more
1.29.0 · source§

impl Clone for Box<CStr>

source§

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

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
1.0.0 · source§

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

source§

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);
source§

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);
1.3.0 · source§

impl Clone for Box<str>

source§

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

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
source§

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

§

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

🔬This is a nightly-only experimental API. (coroutine_trait)
The type of value this coroutine yields. Read more
§

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

🔬This is a nightly-only experimental API. (coroutine_trait)
The type of value this coroutine returns. Read more
source§

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

🔬This is a nightly-only experimental API. (coroutine_trait)
Resumes the execution of this coroutine. Read more
source§

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

§

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

🔬This is a nightly-only experimental API. (coroutine_trait)
The type of value this coroutine yields. Read more
§

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

🔬This is a nightly-only experimental API. (coroutine_trait)
The type of value this coroutine returns. Read more
source§

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

🔬This is a nightly-only experimental API. (coroutine_trait)
Resumes the execution of this coroutine. Read more
1.0.0 · source§

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

source§

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

Formats the value using the given formatter. Read more
1.0.0 · source§

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

source§

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

Returns the “default value” for a type. Read more
1.17.0 · source§

impl Default for Box<CStr>

source§

fn default() -> Box<CStr>

Returns the “default value” for a type. Read more
1.0.0 · source§

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

source§

fn default() -> Box<T>

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

1.17.0 · source§

impl Default for Box<str>

source§

fn default() -> Box<str>

Returns the “default value” for a type. Read more
1.0.0 · source§

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

§

type Target = T

The resulting type after dereferencing.
source§

fn deref(&self) -> &T

Dereferences the value.
1.0.0 · source§

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

source§

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

Mutably dereferences the value.
1.0.0 · source§

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

source§

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

Formats the value using the given formatter. Read more
1.0.0 · source§

impl<I, A> DoubleEndedIterator for Box<I, A>

source§

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

Removes and returns an element from the end of the iterator. Read more
source§

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

Returns the nth element from the end of the iterator. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_advance_by)
Advances the iterator from the back by n elements. Read more
1.27.0 · source§

fn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R
where Self: Sized, 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. Read more
1.27.0 · source§

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

An iterator method that reduces the iterator’s elements to a single, final value, starting from the back. Read more
1.27.0 · source§

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

Searches for an element of an iterator from the back that satisfies a predicate. Read more
1.0.0 · source§

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

source§

fn drop(&mut self)

Executes the destructor for this type. Read more
1.8.0 · source§

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

source§

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()
source§

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

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting
source§

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

Returns the lower-level source of this error, if any. Read more
source§

fn provide<'b>(&'b self, request: &mut Request<'b>)

🔬This is a nightly-only experimental API. (error_generic_member_access)
Provides type-based access to context intended for error reports. Read more
1.0.0 · source§

impl<I, A> ExactSizeIterator for Box<I, A>

source§

fn len(&self) -> usize

Returns the exact remaining length of the iterator. Read more
source§

fn is_empty(&self) -> bool

🔬This is a nightly-only experimental API. (exact_size_is_empty)
Returns true if the iterator is empty. Read more
1.45.0 · source§

impl<A> Extend<Box<str, A>> for String
where A: Allocator,

source§

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

Extends a collection with the contents of an iterator. Read more
source§

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)
Extends a collection with exactly one element.
source§

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. Read more
1.35.0 · source§

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

source§

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.
1.35.0 · source§

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

source§

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.
1.35.0 · source§

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

§

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

The returned type after the call operator is used.
source§

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.
1.17.0 · source§

impl<T> From<&[T]> for Box<[T]>
where T: Clone,

source§

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

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

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

§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:?}");
1.17.0 · source§

impl From<&CStr> for Box<CStr>

source§

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

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

1.6.0 · source§

impl<'a> From<&str> for Box<dyn Error + 'a>

source§

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

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))
1.0.0 · source§

impl<'a> From<&str> for Box<dyn Error + Send + Sync + 'a>

source§

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

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))
1.17.0 · source§

impl From<&str> for Box<str>

source§

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

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}");
1.45.0 · source§

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

source§

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

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:?}");
1.18.0 · source§

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

source§

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

Converts 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]);
1.18.0 · source§

impl From<Box<CStr>> for CString

source§

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

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

§

impl<'a, F> From<Box<F>> for FutureObj<'a, ()>
where F: Future<Output = ()> + Send + 'a,

§

fn from(boxed: Box<F>) -> FutureObj<'a, ()>

Converts to this type from the input type.
§

impl<'a, F> From<Box<F>> for LocalFutureObj<'a, ()>
where F: Future<Output = ()> + 'a,

§

fn from(boxed: Box<F>) -> LocalFutureObj<'a, ()>

Converts to this type from the input type.
1.21.0 · source§

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

source§

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

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[..]);
1.33.0 · source§

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

source§

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.

1.21.0 · source§

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

source§

fn from(v: Box<T, A>) -> Rc<T, A>

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

§Example
let original: Box<i32> = Box::new(1);
let shared: Rc<i32> = Rc::from(original);
assert_eq!(1, *shared);
§

impl<'a> From<Box<dyn Future<Output = ()> + 'a>> for LocalFutureObj<'a, ()>

§

fn from(boxed: Box<dyn Future<Output = ()> + 'a>) -> LocalFutureObj<'a, ()>

Converts to this type from the input type.
§

impl<'a> From<Box<dyn Future<Output = ()> + Send + 'a>> for FutureObj<'a, ()>

§

fn from(boxed: Box<dyn Future<Output = ()> + Send + 'a>) -> FutureObj<'a, ()>

Converts to this type from the input type.
1.18.0 · source§

impl From<Box<str>> for String

source§

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

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

§Examples
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)
1.19.0 · source§

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

source§

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);
1.20.0 · source§

impl From<CString> for Box<CStr>

source§

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

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

1.45.0 · source§

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

source§

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

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.

1.45.0 · source§

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

source§

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

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

1.45.0 · source§

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

source§

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

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}");
1.22.0 · source§

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

source§

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

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))
1.22.0 · source§

impl<'a, 'b> From<Cow<'b, str>> for Box<dyn Error + Send + Sync + 'a>

source§

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

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))
1.0.0 · source§

impl<'a, E> From<E> for Box<dyn Error + 'a>
where E: Error + 'a,

source§

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

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))
1.0.0 · source§

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

source§

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

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))
1.6.0 · source§

impl<'a> From<String> for Box<dyn Error + 'a>

source§

fn from(str_err: String) -> Box<dyn Error + 'a>

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))
1.0.0 · source§

impl<'a> From<String> for Box<dyn Error + Send + Sync + 'a>

source§

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

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))
1.20.0 · source§

impl From<String> for Box<str>

source§

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

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

§Examples
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)
1.6.0 · source§

impl<T> From<T> for Box<T>

source§

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

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);
1.20.0 · source§

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

source§

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

Converts a vector into a boxed slice.

Before doing the conversion, this method discards excess capacity like Vec::shrink_to_fit.

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

Any excess capacity is removed:

let mut vec = Vec::with_capacity(10);
vec.extend([1, 2, 3]);

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

impl<'a> FromIterator<&'a char> for Box<str>

source§

fn from_iter<T>(iter: T) -> Box<str>
where T: IntoIterator<Item = &'a char>,

Creates a value from an iterator. Read more
1.80.0 · source§

impl<'a> FromIterator<&'a str> for Box<str>

source§

fn from_iter<T>(iter: T) -> Box<str>
where T: IntoIterator<Item = &'a str>,

Creates a value from an iterator. Read more
1.80.0 · source§

impl<A> FromIterator<Box<str, A>> for Box<str>
where A: Allocator,

source§

fn from_iter<T>(iter: T) -> Box<str>
where T: IntoIterator<Item = Box<str, A>>,

Creates a value from an iterator. Read more
1.45.0 · source§

impl<A> FromIterator<Box<str, A>> for String
where A: Allocator,

source§

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

Creates a value from an iterator. Read more
1.80.0 · source§

impl<'a> FromIterator<Cow<'a, str>> for Box<str>

source§

fn from_iter<T>(iter: T) -> Box<str>
where T: IntoIterator<Item = Cow<'a, str>>,

Creates a value from an iterator. Read more
1.32.0 · source§

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

source§

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

Creates a value from an iterator. Read more
1.80.0 · source§

impl FromIterator<String> for Box<str>

source§

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

Creates a value from an iterator. Read more
1.80.0 · source§

impl FromIterator<char> for Box<str>

source§

fn from_iter<T>(iter: T) -> Box<str>
where T: IntoIterator<Item = char>,

Creates a value from an iterator. Read more
§

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

§

fn is_terminated(&self) -> bool

Returns true if the stream should no longer be polled.
1.36.0 · source§

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

§

type Output = <F as Future>::Output

The type of value produced on completion.
source§

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

Attempts to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more
1.0.0 · source§

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

source§

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

Feeds this value into the given Hasher. Read more
1.3.0 · source§

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

Feeds a slice of this type into the given Hasher. Read more
1.22.0 · source§

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

source§

fn finish(&self) -> u64

Returns the hash value for the values written so far. Read more
source§

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

Writes some data into this Hasher. Read more
source§

fn write_u8(&mut self, i: u8)

Writes a single u8 into this hasher.
source§

fn write_u16(&mut self, i: u16)

Writes a single u16 into this hasher.
source§

fn write_u32(&mut self, i: u32)

Writes a single u32 into this hasher.
source§

fn write_u64(&mut self, i: u64)

Writes a single u64 into this hasher.
source§

fn write_u128(&mut self, i: u128)

Writes a single u128 into this hasher.
source§

fn write_usize(&mut self, i: usize)

Writes a single usize into this hasher.
source§

fn write_i8(&mut self, i: i8)

Writes a single i8 into this hasher.
source§

fn write_i16(&mut self, i: i16)

Writes a single i16 into this hasher.
source§

fn write_i32(&mut self, i: i32)

Writes a single i32 into this hasher.
source§

fn write_i64(&mut self, i: i64)

Writes a single i64 into this hasher.
source§

fn write_i128(&mut self, i: i128)

Writes a single i128 into this hasher.
source§

fn write_isize(&mut self, i: isize)

Writes a single isize into this hasher.
source§

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. Read more
source§

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

🔬This is a nightly-only experimental API. (hasher_prefixfree_extras)
Writes a single str into this hasher. Read more
1.80.0 · source§

impl<'a, I, A> IntoIterator for &'a Box<[I], A>
where A: Allocator,

§

type IntoIter = Iter<'a, I>

Which kind of iterator are we turning this into?
§

type Item = &'a I

The type of the elements being iterated over.
source§

fn into_iter(self) -> Iter<'a, I>

Creates an iterator from a value. Read more
1.80.0 · source§

impl<'a, I, A> IntoIterator for &'a mut Box<[I], A>
where A: Allocator,

§

type IntoIter = IterMut<'a, I>

Which kind of iterator are we turning this into?
§

type Item = &'a mut I

The type of the elements being iterated over.
source§

fn into_iter(self) -> IterMut<'a, I>

Creates an iterator from a value. Read more
1.80.0 · source§

impl<I, A> IntoIterator for Box<[I], A>
where A: Allocator,

§

type IntoIter = IntoIter<I, A>

Which kind of iterator are we turning this into?
§

type Item = I

The type of the elements being iterated over.
source§

fn into_iter(self) -> IntoIter<I, A>

Creates an iterator from a value. Read more
1.80.0 · source§

impl<'a, I, A> !Iterator for &'a Box<[I], A>
where A: Allocator,

This implementation is required to make sure that the &Box<[I]>: IntoIterator implementation doesn’t overlap with IntoIterator for T where T: Iterator blanket.

§

type Item

The type of the elements being iterated over.
1.0.0 · source§

fn next(&mut self) -> Option<Self::Item>

Advances the iterator and returns the next value. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_next_chunk)
Advances the iterator and returns an array containing the next N values. Read more
1.0.0 · source§

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

Returns the bounds on the remaining length of the iterator. Read more
1.0.0 · source§

fn count(self) -> usize
where Self: Sized,

Consumes the iterator, counting the number of iterations and returning it. Read more
1.0.0 · source§

fn last(self) -> Option<Self::Item>
where Self: Sized,

Consumes the iterator, returning the last element. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_advance_by)
Advances the iterator by n elements. Read more
1.0.0 · source§

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

Returns the nth element of the iterator. Read more
1.28.0 · source§

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

Creates an iterator starting at the same point, but stepping by the given amount at each iteration. Read more
1.0.0 · source§

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

Takes two iterators and creates a new iterator over both in sequence. Read more
1.0.0 · source§

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

‘Zips up’ two iterators into a single iterator of pairs. Read more
source§

fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>
where Self: Sized, 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. Read more
1.0.0 · source§

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

Takes a closure and creates an iterator which calls that closure on each element. Read more
1.21.0 · source§

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

Calls a closure on each element of an iterator. Read more
1.0.0 · source§

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

Creates an iterator which uses a closure to determine if an element should be yielded. Read more
1.0.0 · source§

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

Creates an iterator that both filters and maps. Read more
1.0.0 · source§

fn enumerate(self) -> Enumerate<Self>
where Self: Sized,

Creates an iterator which gives the current iteration count as well as the next value. Read more
1.0.0 · source§

fn peekable(self) -> Peekable<Self>
where Self: Sized,

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. Read more
1.0.0 · source§

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

Creates an iterator that skips elements based on a predicate. Read more
1.0.0 · source§

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

Creates an iterator that yields elements based on a predicate. Read more
1.57.0 · source§

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

Creates an iterator that both yields elements based on a predicate and maps. Read more
1.0.0 · source§

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

Creates an iterator that skips the first n elements. Read more
1.0.0 · source§

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

Creates an iterator that yields the first n elements, or fewer if the underlying iterator ends sooner. Read more
1.0.0 · source§

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

An iterator adapter which, like fold, holds internal state, but unlike fold, produces a new iterator. Read more
1.0.0 · source§

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

Creates an iterator that works like map, but flattens nested structure. Read more
source§

fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>
where Self: Sized, F: FnMut(&[Self::Item; N]) -> R,

🔬This is a nightly-only experimental API. (iter_map_windows)
Calls the given function f for each contiguous window of size N over self and returns an iterator over the outputs of f. Like slice::windows(), the windows during mapping overlap as well. Read more
1.0.0 · source§

fn fuse(self) -> Fuse<Self>
where Self: Sized,

Creates an iterator which ends after the first None. Read more
1.0.0 · source§

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

Does something with each element of an iterator, passing the value on. Read more
1.0.0 · source§

fn by_ref(&mut self) -> &mut Self
where Self: Sized,

Borrows an iterator, rather than consuming it. Read more
1.0.0 · source§

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

Transforms an iterator into a collection. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_collect_into)
Collects all the items from an iterator into a collection. Read more
1.0.0 · source§

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

Consumes an iterator, creating two collections from it. Read more
source§

fn is_partitioned<P>(self, predicate: P) -> bool
where Self: Sized, 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. Read more
1.27.0 · source§

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
where Self: Sized, 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. Read more
1.27.0 · source§

fn try_for_each<F, R>(&mut self, f: F) -> R
where Self: Sized, 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. Read more
1.0.0 · source§

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

Folds every element into an accumulator by applying an operation, returning the final result. Read more
1.51.0 · source§

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

Reduces the elements to a single one, by repeatedly applying a reducing operation. Read more
source§

fn try_reduce<R>( &mut self, f: impl FnMut(Self::Item, Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType
where Self: Sized, 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. Read more
1.0.0 · source§

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

Tests if every element of the iterator matches a predicate. Read more
1.0.0 · source§

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

Tests if any element of the iterator matches a predicate. Read more
1.0.0 · source§

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

Searches for an element of an iterator that satisfies a predicate. Read more
1.30.0 · source§

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

Applies function to the elements of iterator and returns the first non-none result. Read more
source§

fn try_find<R>( &mut self, f: impl FnMut(&Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType
where Self: Sized, 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. Read more
1.0.0 · source§

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

Searches for an element in an iterator, returning its index. Read more
1.6.0 · source§

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

Returns the element that gives the maximum value from the specified function. Read more
1.15.0 · source§

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

Returns the element that gives the maximum value with respect to the specified comparison function. Read more
1.6.0 · source§

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

Returns the element that gives the minimum value from the specified function. Read more
1.15.0 · source§

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

Returns the element that gives the minimum value with respect to the specified comparison function. Read more
1.0.0 · source§

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

Repeats an iterator endlessly. Read more
source§

fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>
where Self: Sized,

🔬This is a nightly-only experimental API. (iter_array_chunks)
Returns an iterator over N elements of the iterator at a time. Read more
1.11.0 · source§

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

Sums the elements of an iterator. Read more
1.11.0 · source§

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

Iterates over the entire iterator, multiplying all the elements Read more
source§

fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering
where Self: Sized, 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. Read more
1.5.0 · source§

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

Lexicographically compares the PartialOrd elements of this Iterator with those of another. The comparison works like short-circuit evaluation, returning a result without comparing the remaining elements. As soon as an order can be determined, the evaluation stops and a result is returned. Read more
source§

fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>
where Self: Sized, 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. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are equal to those of another. Read more
source§

fn eq_by<I, F>(self, other: I, eq: F) -> bool
where Self: Sized, 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. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are not equal to those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically less than those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically less or equal to those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically greater than those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another. Read more
1.82.0 · source§

fn is_sorted_by<F>(self, compare: F) -> bool
where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> bool,

Checks if the elements of this iterator are sorted using the given comparator function. Read more
1.82.0 · source§

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

Checks if the elements of this iterator are sorted using the given key extraction function. Read more
1.80.0 · source§

impl<'a, I, A> !Iterator for &'a mut Box<[I], A>
where A: Allocator,

This implementation is required to make sure that the &mut Box<[I]>: IntoIterator implementation doesn’t overlap with IntoIterator for T where T: Iterator blanket.

§

type Item

The type of the elements being iterated over.
1.0.0 · source§

fn next(&mut self) -> Option<Self::Item>

Advances the iterator and returns the next value. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_next_chunk)
Advances the iterator and returns an array containing the next N values. Read more
1.0.0 · source§

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

Returns the bounds on the remaining length of the iterator. Read more
1.0.0 · source§

fn count(self) -> usize
where Self: Sized,

Consumes the iterator, counting the number of iterations and returning it. Read more
1.0.0 · source§

fn last(self) -> Option<Self::Item>
where Self: Sized,

Consumes the iterator, returning the last element. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_advance_by)
Advances the iterator by n elements. Read more
1.0.0 · source§

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

Returns the nth element of the iterator. Read more
1.28.0 · source§

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

Creates an iterator starting at the same point, but stepping by the given amount at each iteration. Read more
1.0.0 · source§

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

Takes two iterators and creates a new iterator over both in sequence. Read more
1.0.0 · source§

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

‘Zips up’ two iterators into a single iterator of pairs. Read more
source§

fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>
where Self: Sized, 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. Read more
1.0.0 · source§

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

Takes a closure and creates an iterator which calls that closure on each element. Read more
1.21.0 · source§

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

Calls a closure on each element of an iterator. Read more
1.0.0 · source§

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

Creates an iterator which uses a closure to determine if an element should be yielded. Read more
1.0.0 · source§

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

Creates an iterator that both filters and maps. Read more
1.0.0 · source§

fn enumerate(self) -> Enumerate<Self>
where Self: Sized,

Creates an iterator which gives the current iteration count as well as the next value. Read more
1.0.0 · source§

fn peekable(self) -> Peekable<Self>
where Self: Sized,

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. Read more
1.0.0 · source§

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

Creates an iterator that skips elements based on a predicate. Read more
1.0.0 · source§

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

Creates an iterator that yields elements based on a predicate. Read more
1.57.0 · source§

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

Creates an iterator that both yields elements based on a predicate and maps. Read more
1.0.0 · source§

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

Creates an iterator that skips the first n elements. Read more
1.0.0 · source§

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

Creates an iterator that yields the first n elements, or fewer if the underlying iterator ends sooner. Read more
1.0.0 · source§

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

An iterator adapter which, like fold, holds internal state, but unlike fold, produces a new iterator. Read more
1.0.0 · source§

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

Creates an iterator that works like map, but flattens nested structure. Read more
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fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>
where Self: Sized, F: FnMut(&[Self::Item; N]) -> R,

🔬This is a nightly-only experimental API. (iter_map_windows)
Calls the given function f for each contiguous window of size N over self and returns an iterator over the outputs of f. Like slice::windows(), the windows during mapping overlap as well. Read more
1.0.0 · source§

fn fuse(self) -> Fuse<Self>
where Self: Sized,

Creates an iterator which ends after the first None. Read more
1.0.0 · source§

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

Does something with each element of an iterator, passing the value on. Read more
1.0.0 · source§

fn by_ref(&mut self) -> &mut Self
where Self: Sized,

Borrows an iterator, rather than consuming it. Read more
1.0.0 · source§

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

Transforms an iterator into a collection. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_collect_into)
Collects all the items from an iterator into a collection. Read more
1.0.0 · source§

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

Consumes an iterator, creating two collections from it. Read more
source§

fn is_partitioned<P>(self, predicate: P) -> bool
where Self: Sized, 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. Read more
1.27.0 · source§

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
where Self: Sized, 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. Read more
1.27.0 · source§

fn try_for_each<F, R>(&mut self, f: F) -> R
where Self: Sized, 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. Read more
1.0.0 · source§

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

Folds every element into an accumulator by applying an operation, returning the final result. Read more
1.51.0 · source§

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

Reduces the elements to a single one, by repeatedly applying a reducing operation. Read more
source§

fn try_reduce<R>( &mut self, f: impl FnMut(Self::Item, Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType
where Self: Sized, 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. Read more
1.0.0 · source§

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

Tests if every element of the iterator matches a predicate. Read more
1.0.0 · source§

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

Tests if any element of the iterator matches a predicate. Read more
1.0.0 · source§

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

Searches for an element of an iterator that satisfies a predicate. Read more
1.30.0 · source§

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

Applies function to the elements of iterator and returns the first non-none result. Read more
source§

fn try_find<R>( &mut self, f: impl FnMut(&Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType
where Self: Sized, 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. Read more
1.0.0 · source§

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

Searches for an element in an iterator, returning its index. Read more
1.6.0 · source§

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

Returns the element that gives the maximum value from the specified function. Read more
1.15.0 · source§

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

Returns the element that gives the maximum value with respect to the specified comparison function. Read more
1.6.0 · source§

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

Returns the element that gives the minimum value from the specified function. Read more
1.15.0 · source§

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

Returns the element that gives the minimum value with respect to the specified comparison function. Read more
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fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>
where Self: Sized,

🔬This is a nightly-only experimental API. (iter_array_chunks)
Returns an iterator over N elements of the iterator at a time. Read more
1.11.0 · source§

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

Sums the elements of an iterator. Read more
1.11.0 · source§

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

Iterates over the entire iterator, multiplying all the elements Read more
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fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering
where Self: Sized, 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. Read more
1.5.0 · source§

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

Lexicographically compares the PartialOrd elements of this Iterator with those of another. The comparison works like short-circuit evaluation, returning a result without comparing the remaining elements. As soon as an order can be determined, the evaluation stops and a result is returned. Read more
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fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>
where Self: Sized, 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. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are equal to those of another. Read more
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fn eq_by<I, F>(self, other: I, eq: F) -> bool
where Self: Sized, 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. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are not equal to those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically less than those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically less or equal to those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically greater than those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another. Read more
1.82.0 · source§

fn is_sorted_by<F>(self, compare: F) -> bool
where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> bool,

Checks if the elements of this iterator are sorted using the given comparator function. Read more
1.82.0 · source§

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

Checks if the elements of this iterator are sorted using the given key extraction function. Read more
1.80.0 · source§

impl<I, A> !Iterator for Box<[I], A>
where A: Allocator,

This implementation is required to make sure that the Box<[I]>: IntoIterator implementation doesn’t overlap with IntoIterator for T where T: Iterator blanket.

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type Item

The type of the elements being iterated over.
1.0.0 · source§

fn next(&mut self) -> Option<Self::Item>

Advances the iterator and returns the next value. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_next_chunk)
Advances the iterator and returns an array containing the next N values. Read more
1.0.0 · source§

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

Returns the bounds on the remaining length of the iterator. Read more
1.0.0 · source§

fn count(self) -> usize
where Self: Sized,

Consumes the iterator, counting the number of iterations and returning it. Read more
1.0.0 · source§

fn last(self) -> Option<Self::Item>
where Self: Sized,

Consumes the iterator, returning the last element. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_advance_by)
Advances the iterator by n elements. Read more
1.0.0 · source§

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

Returns the nth element of the iterator. Read more
1.28.0 · source§

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

Creates an iterator starting at the same point, but stepping by the given amount at each iteration. Read more
1.0.0 · source§

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

Takes two iterators and creates a new iterator over both in sequence. Read more
1.0.0 · source§

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

‘Zips up’ two iterators into a single iterator of pairs. Read more
source§

fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>
where Self: Sized, 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. Read more
1.0.0 · source§

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

Takes a closure and creates an iterator which calls that closure on each element. Read more
1.21.0 · source§

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

Calls a closure on each element of an iterator. Read more
1.0.0 · source§

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

Creates an iterator which uses a closure to determine if an element should be yielded. Read more
1.0.0 · source§

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

Creates an iterator that both filters and maps. Read more
1.0.0 · source§

fn enumerate(self) -> Enumerate<Self>
where Self: Sized,

Creates an iterator which gives the current iteration count as well as the next value. Read more
1.0.0 · source§

fn peekable(self) -> Peekable<Self>
where Self: Sized,

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. Read more
1.0.0 · source§

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

Creates an iterator that skips elements based on a predicate. Read more
1.0.0 · source§

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

Creates an iterator that yields elements based on a predicate. Read more
1.57.0 · source§

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

Creates an iterator that both yields elements based on a predicate and maps. Read more
1.0.0 · source§

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

Creates an iterator that skips the first n elements. Read more
1.0.0 · source§

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

Creates an iterator that yields the first n elements, or fewer if the underlying iterator ends sooner. Read more
1.0.0 · source§

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

An iterator adapter which, like fold, holds internal state, but unlike fold, produces a new iterator. Read more
1.0.0 · source§

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

Creates an iterator that works like map, but flattens nested structure. Read more
source§

fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>
where Self: Sized, F: FnMut(&[Self::Item; N]) -> R,

🔬This is a nightly-only experimental API. (iter_map_windows)
Calls the given function f for each contiguous window of size N over self and returns an iterator over the outputs of f. Like slice::windows(), the windows during mapping overlap as well. Read more
1.0.0 · source§

fn fuse(self) -> Fuse<Self>
where Self: Sized,

Creates an iterator which ends after the first None. Read more
1.0.0 · source§

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

Does something with each element of an iterator, passing the value on. Read more
1.0.0 · source§

fn by_ref(&mut self) -> &mut Self
where Self: Sized,

Borrows an iterator, rather than consuming it. Read more
1.0.0 · source§

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

Transforms an iterator into a collection. Read more
source§

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

🔬This is a nightly-only experimental API. (iter_collect_into)
Collects all the items from an iterator into a collection. Read more
1.0.0 · source§

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

Consumes an iterator, creating two collections from it. Read more
source§

fn is_partitioned<P>(self, predicate: P) -> bool
where Self: Sized, 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. Read more
1.27.0 · source§

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
where Self: Sized, 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. Read more
1.27.0 · source§

fn try_for_each<F, R>(&mut self, f: F) -> R
where Self: Sized, 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. Read more
1.0.0 · source§

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

Folds every element into an accumulator by applying an operation, returning the final result. Read more
1.51.0 · source§

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

Reduces the elements to a single one, by repeatedly applying a reducing operation. Read more
source§

fn try_reduce<R>( &mut self, f: impl FnMut(Self::Item, Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType
where Self: Sized, 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. Read more
1.0.0 · source§

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

Tests if every element of the iterator matches a predicate. Read more
1.0.0 · source§

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

Tests if any element of the iterator matches a predicate. Read more
1.0.0 · source§

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

Searches for an element of an iterator that satisfies a predicate. Read more
1.30.0 · source§

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

Applies function to the elements of iterator and returns the first non-none result. Read more
source§

fn try_find<R>( &mut self, f: impl FnMut(&Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType
where Self: Sized, 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. Read more
1.0.0 · source§

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

Searches for an element in an iterator, returning its index. Read more
1.6.0 · source§

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

Returns the element that gives the maximum value from the specified function. Read more
1.15.0 · source§

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

Returns the element that gives the maximum value with respect to the specified comparison function. Read more
1.6.0 · source§

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

Returns the element that gives the minimum value from the specified function. Read more
1.15.0 · source§

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

Returns the element that gives the minimum value with respect to the specified comparison function. Read more
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fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>
where Self: Sized,

🔬This is a nightly-only experimental API. (iter_array_chunks)
Returns an iterator over N elements of the iterator at a time. Read more
1.11.0 · source§

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

Sums the elements of an iterator. Read more
1.11.0 · source§

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

Iterates over the entire iterator, multiplying all the elements Read more
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fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering
where Self: Sized, 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. Read more
1.5.0 · source§

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

Lexicographically compares the PartialOrd elements of this Iterator with those of another. The comparison works like short-circuit evaluation, returning a result without comparing the remaining elements. As soon as an order can be determined, the evaluation stops and a result is returned. Read more
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fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>
where Self: Sized, 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. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are equal to those of another. Read more
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fn eq_by<I, F>(self, other: I, eq: F) -> bool
where Self: Sized, 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. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are not equal to those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically less than those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically less or equal to those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically greater than those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another. Read more
1.82.0 · source§

fn is_sorted_by<F>(self, compare: F) -> bool
where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> bool,

Checks if the elements of this iterator are sorted using the given comparator function. Read more
1.82.0 · source§

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

Checks if the elements of this iterator are sorted using the given key extraction function. Read more
1.0.0 · source§

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

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type Item = <I as Iterator>::Item

The type of the elements being iterated over.
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fn next(&mut self) -> Option<<I as Iterator>::Item>

Advances the iterator and returns the next value. Read more
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fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the iterator. Read more
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fn nth(&mut self, n: usize) -> Option<<I as Iterator>::Item>

Returns the nth element of the iterator. Read more
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fn last(self) -> Option<<I as Iterator>::Item>

Consumes the iterator, returning the last element. Read more
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fn next_chunk<const N: usize>( &mut self, ) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>
where Self: Sized,

🔬This is a nightly-only experimental API. (iter_next_chunk)
Advances the iterator and returns an array containing the next N values. Read more
1.0.0 · source§

fn count(self) -> usize
where Self: Sized,

Consumes the iterator, counting the number of iterations and returning it. Read more
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fn advance_by(&mut self, n: usize) -> Result<(), NonZero<usize>>

🔬This is a nightly-only experimental API. (iter_advance_by)
Advances the iterator by n elements. Read more
1.28.0 · source§

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

Creates an iterator starting at the same point, but stepping by the given amount at each iteration. Read more
1.0.0 · source§

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

Takes two iterators and creates a new iterator over both in sequence. Read more
1.0.0 · source§

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

‘Zips up’ two iterators into a single iterator of pairs. Read more
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fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>
where Self: Sized, 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. Read more
1.0.0 · source§

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

Takes a closure and creates an iterator which calls that closure on each element. Read more
1.21.0 · source§

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

Calls a closure on each element of an iterator. Read more
1.0.0 · source§

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

Creates an iterator which uses a closure to determine if an element should be yielded. Read more
1.0.0 · source§

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

Creates an iterator that both filters and maps. Read more
1.0.0 · source§

fn enumerate(self) -> Enumerate<Self>
where Self: Sized,

Creates an iterator which gives the current iteration count as well as the next value. Read more
1.0.0 · source§

fn peekable(self) -> Peekable<Self>
where Self: Sized,

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. Read more
1.0.0 · source§

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

Creates an iterator that skips elements based on a predicate. Read more
1.0.0 · source§

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

Creates an iterator that yields elements based on a predicate. Read more
1.57.0 · source§

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

Creates an iterator that both yields elements based on a predicate and maps. Read more
1.0.0 · source§

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

Creates an iterator that skips the first n elements. Read more
1.0.0 · source§

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

Creates an iterator that yields the first n elements, or fewer if the underlying iterator ends sooner. Read more
1.0.0 · source§

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

An iterator adapter which, like fold, holds internal state, but unlike fold, produces a new iterator. Read more
1.0.0 · source§

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

Creates an iterator that works like map, but flattens nested structure. Read more
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fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>
where Self: Sized, F: FnMut(&[Self::Item; N]) -> R,

🔬This is a nightly-only experimental API. (iter_map_windows)
Calls the given function f for each contiguous window of size N over self and returns an iterator over the outputs of f. Like slice::windows(), the windows during mapping overlap as well. Read more
1.0.0 · source§

fn fuse(self) -> Fuse<Self>
where Self: Sized,

Creates an iterator which ends after the first None. Read more
1.0.0 · source§

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

Does something with each element of an iterator, passing the value on. Read more
1.0.0 · source§

fn by_ref(&mut self) -> &mut Self
where Self: Sized,

Borrows an iterator, rather than consuming it. Read more
1.0.0 · source§

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

Transforms an iterator into a collection. Read more
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fn collect_into<E>(self, collection: &mut E) -> &mut E
where E: Extend<Self::Item>, Self: Sized,

🔬This is a nightly-only experimental API. (iter_collect_into)
Collects all the items from an iterator into a collection. Read more
1.0.0 · source§

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

Consumes an iterator, creating two collections from it. Read more
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fn is_partitioned<P>(self, predicate: P) -> bool
where Self: Sized, 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. Read more
1.27.0 · source§

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
where Self: Sized, 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. Read more
1.27.0 · source§

fn try_for_each<F, R>(&mut self, f: F) -> R
where Self: Sized, 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. Read more
1.0.0 · source§

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

Folds every element into an accumulator by applying an operation, returning the final result. Read more
1.51.0 · source§

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

Reduces the elements to a single one, by repeatedly applying a reducing operation. Read more
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fn try_reduce<R>( &mut self, f: impl FnMut(Self::Item, Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType
where Self: Sized, 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. Read more
1.0.0 · source§

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

Tests if every element of the iterator matches a predicate. Read more
1.0.0 · source§

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

Tests if any element of the iterator matches a predicate. Read more
1.0.0 · source§

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

Searches for an element of an iterator that satisfies a predicate. Read more
1.30.0 · source§

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

Applies function to the elements of iterator and returns the first non-none result. Read more
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fn try_find<R>( &mut self, f: impl FnMut(&Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType
where Self: Sized, 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. Read more
1.0.0 · source§

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

Searches for an element in an iterator, returning its index. Read more
1.6.0 · source§

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

Returns the element that gives the maximum value from the specified function. Read more
1.15.0 · source§

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

Returns the element that gives the maximum value with respect to the specified comparison function. Read more
1.6.0 · source§

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

Returns the element that gives the minimum value from the specified function. Read more
1.15.0 · source§

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

Returns the element that gives the minimum value with respect to the specified comparison function. Read more
1.0.0 · source§

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

Converts an iterator of pairs into a pair of containers. Read more
1.36.0 · source§

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

Creates an iterator which copies all of its elements. Read more
1.0.0 · source§

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

Creates an iterator which clones all of its elements. Read more
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fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>
where Self: Sized,

🔬This is a nightly-only experimental API. (iter_array_chunks)
Returns an iterator over N elements of the iterator at a time. Read more
1.11.0 · source§

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

Sums the elements of an iterator. Read more
1.11.0 · source§

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

Iterates over the entire iterator, multiplying all the elements Read more
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fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering
where Self: Sized, 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. Read more
1.5.0 · source§

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

Lexicographically compares the PartialOrd elements of this Iterator with those of another. The comparison works like short-circuit evaluation, returning a result without comparing the remaining elements. As soon as an order can be determined, the evaluation stops and a result is returned. Read more
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fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>
where Self: Sized, 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. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are equal to those of another. Read more
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fn eq_by<I, F>(self, other: I, eq: F) -> bool
where Self: Sized, 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. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are not equal to those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically less than those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically less or equal to those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically greater than those of another. Read more
1.5.0 · source§

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

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another. Read more
1.82.0 · source§

fn is_sorted_by<F>(self, compare: F) -> bool
where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> bool,

Checks if the elements of this iterator are sorted using the given comparator function. Read more
1.82.0 · source§

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

Checks if the elements of this iterator are sorted using the given key extraction function. Read more
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impl<Sp> LocalSpawn for Box<Sp>
where Sp: LocalSpawn + ?Sized,

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

Spawns a future that will be run to completion. Read more
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fn status_local(&self) -> Result<(), SpawnError>

Determines whether the executor is able to spawn new tasks. Read more
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impl<T> MaxEncodedLen for Box<T>
where T: MaxEncodedLen,

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fn max_encoded_len() -> usize

Upper bound, in bytes, of the maximum encoded size of this item.
1.0.0 · source§

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

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

This method returns an Ordering between self and other. Read more
1.21.0 · source§

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

Compares and returns the maximum of two values. Read more
1.21.0 · source§

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

Compares and returns the minimum of two values. Read more
1.50.0 · source§

fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
1.0.0 · source§

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

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

Tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Box<T, A>) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
1.0.0 · source§

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

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

This method returns an ordering between self and other values if one exists. Read more
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fn lt(&self, other: &Box<T, A>) -> bool

Tests less than (for self and other) and is used by the < operator. Read more
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fn le(&self, other: &Box<T, A>) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator. Read more
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fn ge(&self, other: &Box<T, A>) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator. Read more
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fn gt(&self, other: &Box<T, A>) -> bool

Tests greater than (for self and other) and is used by the > operator. Read more
1.0.0 · source§

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

source§

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

Formats the value using the given formatter. Read more
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impl<S, Item> Sink<Item> for Box<S>
where S: Sink<Item> + Unpin + ?Sized,

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

The type of value produced by the sink when an error occurs.
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fn poll_ready( self: Pin<&mut Box<S>>, cx: &mut Context<'_>, ) -> Poll<Result<(), <Box<S> as Sink<Item>>::Error>>

Attempts to prepare the Sink to receive a value. Read more
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fn start_send( self: Pin<&mut Box<S>>, item: Item, ) -> Result<(), <Box<S> 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(())). Read more
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fn poll_flush( self: Pin<&mut Box<S>>, cx: &mut Context<'_>, ) -> Poll<Result<(), <Box<S> as Sink<Item>>::Error>>

Flush any remaining output from this sink. Read more
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fn poll_close( self: Pin<&mut Box<S>>, cx: &mut Context<'_>, ) -> Poll<Result<(), <Box<S> as Sink<Item>>::Error>>

Flush any remaining output and close this sink, if necessary. Read more
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impl<Sp> Spawn for Box<Sp>
where Sp: Spawn + ?Sized,

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

Spawns a future that will be run to completion. Read more
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fn status(&self) -> Result<(), SpawnError>

Determines whether the executor is able to spawn new tasks. Read more
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impl<S> Stream for Box<S>
where S: Stream + Unpin + ?Sized,

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type Item = <S as Stream>::Item

Values yielded by the stream.
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fn poll_next( self: Pin<&mut Box<S>>, cx: &mut Context<'_>, ) -> Poll<Option<<Box<S> 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. Read more
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fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream. Read more
1.43.0 · source§

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

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

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type Error = Box<[T]>

The type returned in the event of a conversion error.
1.66.0 · source§

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

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

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

Like Vec::into_boxed_slice, this is in-place if vec.capacity() == N, but will require a reallocation otherwise.

§Errors

Returns the original Vec<T> in the Err variant if boxed_slice.len() does not equal N.

§Examples

This can be used with vec! to create an array on the heap:

let state: Box<[f32; 100]> = vec![1.0; 100].try_into().unwrap();
assert_eq!(state.len(), 100);
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type Error = Vec<T>

The type returned in the event of a conversion error.
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impl<T> TypeInfo for Box<T>
where T: TypeInfo + 'static + ?Sized,

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type Identity = T

The type identifying for which type info is provided. Read more
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fn type_info() -> Type

Returns the static type identifier for Self.
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impl<'a, T, F> UnsafeFutureObj<'a, T> for Box<F>
where F: Future<Output = T> + 'a,

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

Convert an owned instance into a (conceptually owned) fat pointer. Read more
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unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer. Read more
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impl<'a, T> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + 'a>
where T: 'a,

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

Convert an owned instance into a (conceptually owned) fat pointer. Read more
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unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer. Read more
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impl<'a, T> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + Send + 'a>
where T: 'a,

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

Convert an owned instance into a (conceptually owned) fat pointer. Read more
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unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer. Read more
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impl<'a, T, F> UnsafeFutureObj<'a, T> for Pin<Box<F>>
where F: Future<Output = T> + 'a,

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

Convert an owned instance into a (conceptually owned) fat pointer. Read more
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unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer. Read more
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impl<'a, T> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + 'a>>
where T: 'a,

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

Convert an owned instance into a (conceptually owned) fat pointer. Read more
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unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer. Read more
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impl<'a, T> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + Send + 'a>>
where T: 'a,

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

Convert an owned instance into a (conceptually owned) fat pointer. Read more
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unsafe fn drop(ptr: *mut dyn Future<Output = T> + 'a)

Drops the future represented by the given fat pointer. Read more
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impl<T> WrapperTypeDecode for Box<T>

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type Wrapped = T

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

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impl<T> ConstEncodedLen for Box<T>
where T: ConstEncodedLen,

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

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

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impl<T> EncodeLike<T> for Box<T>
where T: Encode,

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

1.0.0 · source§

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

1.26.0 · source§

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

1.33.0 · source§

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

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impl<T> WrapperTypeEncode for Box<T>
where T: ?Sized,

Auto Trait Implementations§

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

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impl<T, A> RefUnwindSafe for Box<T, A>

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

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

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

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T, U> AsByteSlice<T> for U
where T: ToByteSlice, U: AsRef<[T]> + ?Sized,

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

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impl<T, U> AsMutByteSlice<T> for U
where T: ToMutByteSlice, U: AsMut<[T]> + ?Sized,

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fn as_mut_byte_slice(&mut self) -> &mut [u8]

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impl<U> AsMutSliceOf for U
where U: AsMut<[u8]> + ?Sized,

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fn as_mut_slice_of<T>(&mut self) -> Result<&mut [T], Error>
where T: FromByteSlice,

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impl<U> AsSliceOf for U
where U: AsRef<[u8]> + ?Sized,

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fn as_slice_of<T>(&self) -> Result<&[T], Error>
where T: FromByteSlice,

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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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default unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
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impl<T, X> Decode for X
where T: Decode + Into<X>, X: WrapperTypeDecode<Wrapped = T>,

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fn decode<I>(input: &mut I) -> Result<X, Error>
where I: Input,

Attempt to deserialise the value from input.
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fn decode_into<I>( input: &mut I, dst: &mut MaybeUninit<Self>, ) -> Result<DecodeFinished, Error>
where I: Input,

Attempt to deserialize the value from input into a pre-allocated piece of memory. Read more
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fn skip<I>(input: &mut I) -> Result<(), Error>
where I: Input,

Attempt to skip the encoded value from input. Read more
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fn encoded_fixed_size() -> Option<usize>

Returns the fixed encoded size of the type. Read more
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impl<T> DecodeAll for T
where T: Decode,

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fn decode_all(input: &mut &[u8]) -> Result<T, Error>

Decode Self and consume all of the given input data. Read more
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impl<T> DecodeLimit for T
where T: Decode,

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fn decode_all_with_depth_limit( limit: u32, input: &mut &[u8], ) -> Result<T, Error>

Decode Self and consume all of the given input data. Read more
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fn decode_with_depth_limit<I>(limit: u32, input: &mut I) -> Result<T, Error>
where I: Input,

Decode Self with the given maximum recursion depth and advance input by the number of bytes consumed. Read more
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impl<T, X> Encode for X
where T: Encode + ?Sized, X: WrapperTypeEncode<Target = T>,

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fn size_hint(&self) -> usize

If possible give a hint of expected size of the encoding. Read more
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fn using_encoded<R, F>(&self, f: F) -> R
where F: FnOnce(&[u8]) -> R,

Convert self to a slice and then invoke the given closure with it.
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fn encode(&self) -> Vec<u8>

Convert self to an owned vector.
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fn encode_to<W>(&self, dest: &mut W)
where W: Output + ?Sized,

Convert self to a slice and append it to the destination.
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fn encoded_size(&self) -> usize

Calculates the encoded size. Read more
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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
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impl<T> From<!> for T

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fn from(t: !) -> T

Converts to this type from the input type.
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> FutureExt for T
where T: Future + ?Sized,

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fn map<U, F>(self, f: F) -> Map<Self, F>
where F: FnOnce(Self::Output) -> U, Self: Sized,

Map this future’s output to a different type, returning a new future of the resulting type. Read more
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fn map_into<U>(self) -> MapInto<Self, U>
where Self::Output: Into<U>, Self: Sized,

Map this future’s output to a different type, returning a new future of the resulting type. Read more
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fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F>
where F: FnOnce(Self::Output) -> Fut, Fut: Future, Self: Sized,

Chain on a computation for when a future finished, passing the result of the future to the provided closure f. Read more
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fn left_future<B>(self) -> Either<Self, B>
where B: Future<Output = Self::Output>, Self: Sized,

Wrap this future in an Either future, making it the left-hand variant of that Either. Read more
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fn right_future<A>(self) -> Either<A, Self>
where A: Future<Output = Self::Output>, Self: Sized,

Wrap this future in an Either future, making it the right-hand variant of that Either. Read more
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fn into_stream(self) -> IntoStream<Self>
where Self: Sized,

Convert this future into a single element stream. Read more
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fn flatten(self) -> Flatten<Self>
where Self::Output: Future, Self: Sized,

Flatten the execution of this future when the output of this future is itself another future. Read more
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fn flatten_stream(self) -> FlattenStream<Self>
where Self::Output: Stream, Self: Sized,

Flatten the execution of this future when the successful result of this future is a stream. Read more
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fn fuse(self) -> Fuse<Self>
where Self: Sized,

Fuse a future such that poll will never again be called once it has completed. This method can be used to turn any Future into a FusedFuture. Read more
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fn inspect<F>(self, f: F) -> Inspect<Self, F>
where F: FnOnce(&Self::Output), Self: Sized,

Do something with the output of a future before passing it on. Read more
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fn boxed<'a>(self) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'a>>
where Self: Sized + Send + 'a,

Wrap the future in a Box, pinning it. Read more
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fn boxed_local<'a>(self) -> Pin<Box<dyn Future<Output = Self::Output> + 'a>>
where Self: Sized + 'a,

Wrap the future in a Box, pinning it. Read more
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fn unit_error(self) -> UnitError<Self>
where Self: Sized,

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fn never_error(self) -> NeverError<Self>
where Self: Sized,

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fn poll_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Self::Output>
where Self: Unpin,

A convenience for calling Future::poll on Unpin future types.
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fn now_or_never(self) -> Option<Self::Output>
where Self: Sized,

Evaluates and consumes the future, returning the resulting output if the future is ready after the first call to Future::poll. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<I> IntoAsyncIterator for I
where I: AsyncIterator,

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type Item = <I as AsyncIterator>::Item

🔬This is a nightly-only experimental API. (async_iterator)
The type of the item yielded by the iterator
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type IntoAsyncIter = I

🔬This is a nightly-only experimental API. (async_iterator)
The type of the resulting iterator
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fn into_async_iter(self) -> <I as IntoAsyncIterator>::IntoAsyncIter

🔬This is a nightly-only experimental API. (async_iterator)
Converts self into an async iterator
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impl<F> IntoFuture for F
where F: Future,

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type Output = <F as Future>::Output

The output that the future will produce on completion.
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type IntoFuture = F

Which kind of future are we turning this into?
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fn into_future(self) -> <F as IntoFuture>::IntoFuture

Creates a future from a value. Read more
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impl<I> IntoIterator for I
where I: Iterator,

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type Item = <I as Iterator>::Item

The type of the elements being iterated over.
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type IntoIter = I

Which kind of iterator are we turning this into?
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fn into_iter(self) -> I

Creates an iterator from a value. Read more
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impl<T> KeyedVec for T
where T: Codec,

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fn to_keyed_vec(&self, prepend_key: &[u8]) -> Vec<u8>

Return an encoding of Self prepended by given slice.
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impl<Sp> LocalSpawnExt for Sp
where Sp: LocalSpawn + ?Sized,

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fn spawn_local<Fut>(&self, future: Fut) -> Result<(), SpawnError>
where Fut: Future<Output = ()> + 'static,

Spawns a task that polls the given future with output () to completion. Read more
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impl<F> Pattern for F
where F: FnMut(char) -> bool,

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type Searcher<'a> = CharPredicateSearcher<'a, F>

🔬This is a nightly-only experimental API. (pattern)
Associated searcher for this pattern
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fn into_searcher<'a>(self, haystack: &'a str) -> CharPredicateSearcher<'a, F>

🔬This is a nightly-only experimental API. (pattern)
Constructs the associated searcher from self and the haystack to search in.
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fn is_contained_in<'a>(self, haystack: &'a str) -> bool

🔬This is a nightly-only experimental API. (pattern)
Checks whether the pattern matches anywhere in the haystack
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fn is_prefix_of<'a>(self, haystack: &'a str) -> bool

🔬This is a nightly-only experimental API. (pattern)
Checks whether the pattern matches at the front of the haystack
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fn strip_prefix_of<'a>(self, haystack: &'a str) -> Option<&'a str>

🔬This is a nightly-only experimental API. (pattern)
Removes the pattern from the front of haystack, if it matches.
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fn is_suffix_of<'a>(self, haystack: &'a str) -> bool

🔬This is a nightly-only experimental API. (pattern)
Checks whether the pattern matches at the back of the haystack
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fn strip_suffix_of<'a>(self, haystack: &'a str) -> Option<&'a str>

🔬This is a nightly-only experimental API. (pattern)
Removes the pattern from the back of haystack, if it matches.
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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T, Item> SinkExt<Item> for T
where T: Sink<Item> + ?Sized,

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fn with<U, Fut, F, E>(self, f: F) -> With<Self, Item, U, Fut, F>
where F: FnMut(U) -> Fut, Fut: Future<Output = Result<Item, E>>, E: From<Self::Error>, Self: Sized,

Composes a function in front of the sink. Read more
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fn with_flat_map<U, St, F>(self, f: F) -> WithFlatMap<Self, Item, U, St, F>
where F: FnMut(U) -> St, St: Stream<Item = Result<Item, Self::Error>>, Self: Sized,

Composes a function in front of the sink. Read more
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fn sink_map_err<E, F>(self, f: F) -> SinkMapErr<Self, F>
where F: FnOnce(Self::Error) -> E, Self: Sized,

Transforms the error returned by the sink.
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fn sink_err_into<E>(self) -> SinkErrInto<Self, Item, E>
where Self: Sized, Self::Error: Into<E>,

Map this sink’s error to a different error type using the Into trait. Read more
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fn buffer(self, capacity: usize) -> Buffer<Self, Item>
where Self: Sized,

Adds a fixed-size buffer to the current sink. Read more
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fn close(&mut self) -> Close<'_, Self, Item>
where Self: Unpin,

Close the sink.
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fn fanout<Si>(self, other: Si) -> Fanout<Self, Si>
where Self: Sized, Item: Clone, Si: Sink<Item, Error = Self::Error>,

Fanout items to multiple sinks. Read more
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fn flush(&mut self) -> Flush<'_, Self, Item>
where Self: Unpin,

Flush the sink, processing all pending items. Read more
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fn send(&mut self, item: Item) -> Send<'_, Self, Item>
where Self: Unpin,

A future that completes after the given item has been fully processed into the sink, including flushing. Read more
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fn feed(&mut self, item: Item) -> Feed<'_, Self, Item>
where Self: Unpin,

A future that completes after the given item has been received by the sink. Read more
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fn send_all<'a, St>(&'a mut self, stream: &'a mut St) -> SendAll<'a, Self, St>
where St: TryStream<Ok = Item, Error = Self::Error> + Stream + Unpin + ?Sized, Self: Unpin,

A future that completes after the given stream has been fully processed into the sink, including flushing. Read more
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fn left_sink<Si2>(self) -> Either<Self, Si2>
where Si2: Sink<Item, Error = Self::Error>, Self: Sized,

Wrap this sink in an Either sink, making it the left-hand variant of that Either. Read more
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fn right_sink<Si1>(self) -> Either<Si1, Self>
where Si1: Sink<Item, Error = Self::Error>, Self: Sized,

Wrap this stream in an Either stream, making it the right-hand variant of that Either. Read more
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fn poll_ready_unpin( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<(), Self::Error>>
where Self: Unpin,

A convenience method for calling [Sink::poll_ready] on Unpin sink types.
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fn start_send_unpin(&mut self, item: Item) -> Result<(), Self::Error>
where Self: Unpin,

A convenience method for calling [Sink::start_send] on Unpin sink types.
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fn poll_flush_unpin( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<(), Self::Error>>
where Self: Unpin,

A convenience method for calling [Sink::poll_flush] on Unpin sink types.
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fn poll_close_unpin( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<(), Self::Error>>
where Self: Unpin,

A convenience method for calling [Sink::poll_close] on Unpin sink types.
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impl<Sp> SpawnExt for Sp
where Sp: Spawn + ?Sized,

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fn spawn<Fut>(&self, future: Fut) -> Result<(), SpawnError>
where Fut: Future<Output = ()> + Send + 'static,

Spawns a task that polls the given future with output () to completion. Read more
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impl<T> StreamExt for T
where T: Stream + ?Sized,

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fn next(&mut self) -> Next<'_, Self>
where Self: Unpin,

Creates a future that resolves to the next item in the stream. Read more
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fn into_future(self) -> StreamFuture<Self>
where Self: Sized + Unpin,

Converts this stream into a future of (next_item, tail_of_stream). If the stream terminates, then the next item is None. Read more
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fn map<T, F>(self, f: F) -> Map<Self, F>
where F: FnMut(Self::Item) -> T, Self: Sized,

Maps this stream’s items to a different type, returning a new stream of the resulting type. Read more
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fn enumerate(self) -> Enumerate<Self>
where Self: Sized,

Creates a stream which gives the current iteration count as well as the next value. Read more
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fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F>
where F: FnMut(&Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,

Filters the values produced by this stream according to the provided asynchronous predicate. Read more
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fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F>
where F: FnMut(Self::Item) -> Fut, Fut: Future<Output = Option<T>>, Self: Sized,

Filters the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more
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fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F>
where F: FnMut(Self::Item) -> Fut, Fut: Future, Self: Sized,

Computes from this stream’s items new items of a different type using an asynchronous closure. Read more
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fn collect<C>(self) -> Collect<Self, C>
where C: Default + Extend<Self::Item>, Self: Sized,

Transforms a stream into a collection, returning a future representing the result of that computation. Read more
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fn unzip<A, B, FromA, FromB>(self) -> Unzip<Self, FromA, FromB>
where FromA: Default + Extend<A>, FromB: Default + Extend<B>, Self: Sized + Stream<Item = (A, B)>,

Converts a stream of pairs into a future, which resolves to pair of containers. Read more
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fn concat(self) -> Concat<Self>
where Self: Sized, Self::Item: Extend<<Self::Item as IntoIterator>::Item> + IntoIterator + Default,

Concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more
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fn count(self) -> Count<Self>
where Self: Sized,

Drives the stream to completion, counting the number of items. Read more
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fn cycle(self) -> Cycle<Self>
where Self: Sized + Clone,

Repeats a stream endlessly. Read more
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fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F>
where F: FnMut(T, Self::Item) -> Fut, Fut: Future<Output = T>, Self: Sized,

Execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more
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fn any<Fut, F>(self, f: F) -> Any<Self, Fut, F>
where F: FnMut(Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,

Execute predicate over asynchronous stream, and return true if any element in stream satisfied a predicate. Read more
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fn all<Fut, F>(self, f: F) -> All<Self, Fut, F>
where F: FnMut(Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,

Execute predicate over asynchronous stream, and return true if all element in stream satisfied a predicate. Read more
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fn flatten(self) -> Flatten<Self>
where Self::Item: Stream, Self: Sized,

Flattens a stream of streams into just one continuous stream. Read more
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fn flatten_unordered( self, limit: impl Into<Option<usize>>, ) -> FlattenUnorderedWithFlowController<Self, ()>
where Self::Item: Stream + Unpin, Self: Sized,

Flattens a stream of streams into just one continuous stream. Polls inner streams produced by the base stream concurrently. Read more
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fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>
where F: FnMut(Self::Item) -> U, U: Stream, Self: Sized,

Maps a stream like [StreamExt::map] but flattens nested Streams. Read more
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fn flat_map_unordered<U, F>( self, limit: impl Into<Option<usize>>, f: F, ) -> FlatMapUnordered<Self, U, F>
where U: Stream + Unpin, F: FnMut(Self::Item) -> U, Self: Sized,

Maps a stream like [StreamExt::map] but flattens nested Streams and polls them concurrently, yielding items in any order, as they made available. Read more
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fn scan<S, B, Fut, F>(self, initial_state: S, f: F) -> Scan<Self, S, Fut, F>
where F: FnMut(&mut S, Self::Item) -> Fut, Fut: Future<Output = Option<B>>, Self: Sized,

Combinator similar to [StreamExt::fold] that holds internal state and produces a new stream. Read more
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fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F>
where F: FnMut(&Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,

Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more
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fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F>
where F: FnMut(&Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,

Take elements from this stream while the provided asynchronous predicate resolves to true. Read more
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fn take_until<Fut>(self, fut: Fut) -> TakeUntil<Self, Fut>
where Fut: Future, Self: Sized,

Take elements from this stream until the provided future resolves. Read more
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fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F>
where F: FnMut(Self::Item) -> Fut, Fut: Future<Output = ()>, Self: Sized,

Runs this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more
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fn for_each_concurrent<Fut, F>( self, limit: impl Into<Option<usize>>, f: F, ) -> ForEachConcurrent<Self, Fut, F>
where F: FnMut(Self::Item) -> Fut, Fut: Future<Output = ()>, Self: Sized,

Runs this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available. Read more
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fn take(self, n: usize) -> Take<Self>
where Self: Sized,

Creates a new stream of at most n items of the underlying stream. Read more
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fn skip(self, n: usize) -> Skip<Self>
where Self: Sized,

Creates a new stream which skips n items of the underlying stream. Read more
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fn fuse(self) -> Fuse<Self>
where Self: Sized,

Fuse a stream such that poll_next will never again be called once it has finished. This method can be used to turn any Stream into a FusedStream. Read more
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fn by_ref(&mut self) -> &mut Self

Borrows a stream, rather than consuming it. Read more
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fn boxed<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + Send + 'a>>
where Self: Sized + Send + 'a,

Wrap the stream in a Box, pinning it. Read more
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fn boxed_local<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a>>
where Self: Sized + 'a,

Wrap the stream in a Box, pinning it. Read more
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fn buffered(self, n: usize) -> Buffered<Self>
where Self::Item: Future, Self: Sized,

An adaptor for creating a buffered list of pending futures. Read more
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fn buffer_unordered(self, n: usize) -> BufferUnordered<Self>
where Self::Item: Future, Self: Sized,

An adaptor for creating a buffered list of pending futures (unordered). Read more
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fn zip<St>(self, other: St) -> Zip<Self, St>
where St: Stream, Self: Sized,

An adapter for zipping two streams together. Read more
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fn chain<St>(self, other: St) -> Chain<Self, St>
where St: Stream<Item = Self::Item>, Self: Sized,

Adapter for chaining two streams. Read more
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fn peekable(self) -> Peekable<Self>
where Self: Sized,

Creates a new stream which exposes a peek method. Read more
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fn chunks(self, capacity: usize) -> Chunks<Self>
where Self: Sized,

An adaptor for chunking up items of the stream inside a vector. Read more
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fn ready_chunks(self, capacity: usize) -> ReadyChunks<Self>
where Self: Sized,

An adaptor for chunking up ready items of the stream inside a vector. Read more
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fn forward<S>(self, sink: S) -> Forward<Self, S>
where S: Sink<Self::Ok, Error = Self::Error>, Self: Sized + TryStream,

A future that completes after the given stream has been fully processed into the sink and the sink has been flushed and closed. Read more
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fn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>)
where Self: Sized + Sink<Item>,

Splits this Stream + Sink object into separate Sink and Stream objects. Read more
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fn inspect<F>(self, f: F) -> Inspect<Self, F>
where F: FnMut(&Self::Item), Self: Sized,

Do something with each item of this stream, afterwards passing it on. Read more
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fn left_stream<B>(self) -> Either<Self, B>
where B: Stream<Item = Self::Item>, Self: Sized,

Wrap this stream in an Either stream, making it the left-hand variant of that Either. Read more
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fn right_stream<B>(self) -> Either<B, Self>
where B: Stream<Item = Self::Item>, Self: Sized,

Wrap this stream in an Either stream, making it the right-hand variant of that Either. Read more
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fn poll_next_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Option<Self::Item>>
where Self: Unpin,

A convenience method for calling [Stream::poll_next] on Unpin stream types.
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fn select_next_some(&mut self) -> SelectNextSome<'_, Self>
where Self: Unpin + FusedStream,

Returns a Future that resolves when the next item in this stream is ready. Read more
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impl<T> ToHex for T
where T: AsRef<[u8]>,

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fn encode_hex<U>(&self) -> U
where U: FromIterator<char>,

Encode the hex strict representing self into the result. Lower case letters are used (e.g. f9b4ca)
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fn encode_hex_upper<U>(&self) -> U
where U: FromIterator<char>,

Encode the hex strict representing self into the result. Upper case letters are used (e.g. F9B4CA)
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T> ToString for T
where T: Display + ?Sized,

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default fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<F, T, E> TryFuture for F
where F: Future<Output = Result<T, E>> + ?Sized,

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type Ok = T

The type of successful values yielded by this future
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type Error = E

The type of failures yielded by this future
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fn try_poll( self: Pin<&mut F>, cx: &mut Context<'_>, ) -> Poll<<F as Future>::Output>

Poll this TryFuture as if it were a Future. Read more
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impl<Fut> TryFutureExt for Fut
where Fut: TryFuture + ?Sized,

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fn flatten_sink<Item>(self) -> FlattenSink<Self, Self::Ok>
where Self::Ok: Sink<Item, Error = Self::Error>, Self: Sized,

Flattens the execution of this future when the successful result of this future is a [Sink]. Read more
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fn map_ok<T, F>(self, f: F) -> MapOk<Self, F>
where F: FnOnce(Self::Ok) -> T, Self: Sized,

Maps this future’s success value to a different value. Read more
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fn map_ok_or_else<T, E, F>(self, e: E, f: F) -> MapOkOrElse<Self, F, E>
where F: FnOnce(Self::Ok) -> T, E: FnOnce(Self::Error) -> T, Self: Sized,

Maps this future’s success value to a different value, and permits for error handling resulting in the same type. Read more
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fn map_err<E, F>(self, f: F) -> MapErr<Self, F>
where F: FnOnce(Self::Error) -> E, Self: Sized,

Maps this future’s error value to a different value. Read more
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fn err_into<E>(self) -> ErrInto<Self, E>
where Self: Sized, Self::Error: Into<E>,

Maps this future’s Error to a new error type using the Into trait. Read more
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fn ok_into<U>(self) -> OkInto<Self, U>
where Self: Sized, Self::Ok: Into<U>,

Maps this future’s Ok to a new type using the Into trait.
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fn and_then<Fut, F>(self, f: F) -> AndThen<Self, Fut, F>
where F: FnOnce(Self::Ok) -> Fut, Fut: TryFuture<Error = Self::Error>, Self: Sized,

Executes another future after this one resolves successfully. The success value is passed to a closure to create this subsequent future. Read more
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fn or_else<Fut, F>(self, f: F) -> OrElse<Self, Fut, F>
where F: FnOnce(Self::Error) -> Fut, Fut: TryFuture<Ok = Self::Ok>, Self: Sized,

Executes another future if this one resolves to an error. The error value is passed to a closure to create this subsequent future. Read more
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fn inspect_ok<F>(self, f: F) -> InspectOk<Self, F>
where F: FnOnce(&Self::Ok), Self: Sized,

Do something with the success value of a future before passing it on. Read more
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fn inspect_err<F>(self, f: F) -> InspectErr<Self, F>
where F: FnOnce(&Self::Error), Self: Sized,

Do something with the error value of a future before passing it on. Read more
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fn try_flatten(self) -> TryFlatten<Self, Self::Ok>
where Self::Ok: TryFuture<Error = Self::Error>, Self: Sized,

Flatten the execution of this future when the successful result of this future is another future. Read more
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fn try_flatten_stream(self) -> TryFlattenStream<Self>
where Self::Ok: TryStream<Error = Self::Error>, Self: Sized,

Flatten the execution of this future when the successful result of this future is a stream. Read more
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fn unwrap_or_else<F>(self, f: F) -> UnwrapOrElse<Self, F>
where Self: Sized, F: FnOnce(Self::Error) -> Self::Ok,

Unwraps this future’s output, producing a future with this future’s Ok type as its Output type. Read more
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fn into_future(self) -> IntoFuture<Self>
where Self: Sized,

Wraps a [TryFuture] into a type that implements Future. Read more
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fn try_poll_unpin( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<Self::Ok, Self::Error>>
where Self: Unpin,

A convenience method for calling [TryFuture::try_poll] on Unpin future types.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<S, T, E> TryStream for S
where S: Stream<Item = Result<T, E>> + ?Sized,

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type Ok = T

The type of successful values yielded by this future
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type Error = E

The type of failures yielded by this future
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fn try_poll_next( self: Pin<&mut S>, cx: &mut Context<'_>, ) -> Poll<Option<Result<<S as TryStream>::Ok, <S as TryStream>::Error>>>

Poll this TryStream as if it were a Stream. Read more
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impl<S> TryStreamExt for S
where S: TryStream + ?Sized,

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fn err_into<E>(self) -> ErrInto<Self, E>
where Self: Sized, Self::Error: Into<E>,

Wraps the current stream in a new stream which converts the error type into the one provided. Read more
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fn map_ok<T, F>(self, f: F) -> MapOk<Self, F>
where Self: Sized, F: FnMut(Self::Ok) -> T,

Wraps the current stream in a new stream which maps the success value using the provided closure. Read more
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fn map_err<E, F>(self, f: F) -> MapErr<Self, F>
where Self: Sized, F: FnMut(Self::Error) -> E,

Wraps the current stream in a new stream which maps the error value using the provided closure. Read more
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fn and_then<Fut, F>(self, f: F) -> AndThen<Self, Fut, F>
where F: FnMut(Self::Ok) -> Fut, Fut: TryFuture<Error = Self::Error>, Self: Sized,

Chain on a computation for when a value is ready, passing the successful results to the provided closure f. Read more
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fn or_else<Fut, F>(self, f: F) -> OrElse<Self, Fut, F>
where F: FnMut(Self::Error) -> Fut, Fut: TryFuture<Ok = Self::Ok>, Self: Sized,

Chain on a computation for when an error happens, passing the erroneous result to the provided closure f. Read more
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fn inspect_ok<F>(self, f: F) -> InspectOk<Self, F>
where F: FnMut(&Self::Ok), Self: Sized,

Do something with the success value of this stream, afterwards passing it on. Read more
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fn inspect_err<F>(self, f: F) -> InspectErr<Self, F>
where F: FnMut(&Self::Error), Self: Sized,

Do something with the error value of this stream, afterwards passing it on. Read more
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fn into_stream(self) -> IntoStream<Self>
where Self: Sized,

Wraps a [TryStream] into a type that implements Stream Read more
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fn try_next(&mut self) -> TryNext<'_, Self>
where Self: Unpin,

Creates a future that attempts to resolve the next item in the stream. If an error is encountered before the next item, the error is returned instead. Read more
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fn try_for_each<Fut, F>(self, f: F) -> TryForEach<Self, Fut, F>
where F: FnMut(Self::Ok) -> Fut, Fut: TryFuture<Ok = (), Error = Self::Error>, Self: Sized,

Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more
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fn try_skip_while<Fut, F>(self, f: F) -> TrySkipWhile<Self, Fut, F>
where F: FnMut(&Self::Ok) -> Fut, Fut: TryFuture<Ok = bool, Error = Self::Error>, Self: Sized,

Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more
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fn try_take_while<Fut, F>(self, f: F) -> TryTakeWhile<Self, Fut, F>
where F: FnMut(&Self::Ok) -> Fut, Fut: TryFuture<Ok = bool, Error = Self::Error>, Self: Sized,

Take elements on this stream while the provided asynchronous predicate resolves to true. Read more
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fn try_for_each_concurrent<Fut, F>( self, limit: impl Into<Option<usize>>, f: F, ) -> TryForEachConcurrent<Self, Fut, F>
where F: FnMut(Self::Ok) -> Fut, Fut: Future<Output = Result<(), Self::Error>>, Self: Sized,

Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available, exiting as soon as an error occurs. Read more
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fn try_collect<C>(self) -> TryCollect<Self, C>
where C: Default + Extend<Self::Ok>, Self: Sized,

Attempt to transform a stream into a collection, returning a future representing the result of that computation. Read more
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fn try_chunks(self, capacity: usize) -> TryChunks<Self>
where Self: Sized,

An adaptor for chunking up successful items of the stream inside a vector. Read more
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fn try_ready_chunks(self, capacity: usize) -> TryReadyChunks<Self>
where Self: Sized,

An adaptor for chunking up successful, ready items of the stream inside a vector. Read more
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fn try_filter<Fut, F>(self, f: F) -> TryFilter<Self, Fut, F>
where Fut: Future<Output = bool>, F: FnMut(&Self::Ok) -> Fut, Self: Sized,

Attempt to filter the values produced by this stream according to the provided asynchronous closure. Read more
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fn try_filter_map<Fut, F, T>(self, f: F) -> TryFilterMap<Self, Fut, F>
where Fut: TryFuture<Ok = Option<T>, Error = Self::Error>, F: FnMut(Self::Ok) -> Fut, Self: Sized,

Attempt to filter the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more
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fn try_flatten_unordered( self, limit: impl Into<Option<usize>>, ) -> TryFlattenUnordered<Self>
where Self::Ok: TryStream + Unpin, <Self::Ok as TryStream>::Error: From<Self::Error>, Self: Sized,

Flattens a stream of streams into just one continuous stream. Produced streams will be polled concurrently and any errors will be passed through without looking at them. If the underlying base stream returns an error, it will be immediately propagated. Read more
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fn try_flatten(self) -> TryFlatten<Self>
where Self::Ok: TryStream, <Self::Ok as TryStream>::Error: From<Self::Error>, Self: Sized,

Flattens a stream of streams into just one continuous stream. Read more
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fn try_fold<T, Fut, F>(self, init: T, f: F) -> TryFold<Self, Fut, T, F>
where F: FnMut(T, Self::Ok) -> Fut, Fut: TryFuture<Ok = T, Error = Self::Error>, Self: Sized,

Attempt to execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more
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fn try_concat(self) -> TryConcat<Self>
where Self: Sized, Self::Ok: Extend<<Self::Ok as IntoIterator>::Item> + IntoIterator + Default,

Attempt to concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more
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fn try_buffer_unordered(self, n: usize) -> TryBufferUnordered<Self>
where Self::Ok: TryFuture<Error = Self::Error>, Self: Sized,

Attempt to execute several futures from a stream concurrently (unordered). Read more
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fn try_buffered(self, n: usize) -> TryBuffered<Self>
where Self::Ok: TryFuture<Error = Self::Error>, Self: Sized,

Attempt to execute several futures from a stream concurrently. Read more
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fn try_poll_next_unpin( &mut self, cx: &mut Context<'_>, ) -> Poll<Option<Result<Self::Ok, Self::Error>>>
where Self: Unpin,

A convenience method for calling [TryStream::try_poll_next] on Unpin stream types.
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fn try_all<Fut, F>(self, f: F) -> TryAll<Self, Fut, F>
where Self: Sized, F: FnMut(Self::Ok) -> Fut, Fut: Future<Output = bool>,

Attempt to execute a predicate over an asynchronous stream and evaluate if all items satisfy the predicate. Exits early if an Err is encountered or if an Ok item is found that does not satisfy the predicate. Read more
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fn try_any<Fut, F>(self, f: F) -> TryAny<Self, Fut, F>
where Self: Sized, F: FnMut(Self::Ok) -> Fut, Fut: Future<Output = bool>,

Attempt to execute a predicate over an asynchronous stream and evaluate if any items satisfy the predicate. Exits early if an Err is encountered or if an Ok item is found that satisfies the predicate. Read more
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impl<S> Codec for S
where S: Decode + Encode,

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impl<T> EncodeLike<&&T> for T
where T: Encode,

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impl<T> EncodeLike<&T> for T
where T: Encode,

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impl<T> EncodeLike<&mut T> for T
where T: Encode,

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impl<T> EncodeLike<Arc<T>> for T
where T: Encode,

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impl<T> EncodeLike<Box<T>> for T
where T: Encode,

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impl<'a, T> EncodeLike<Cow<'a, T>> for T
where T: ToOwned + Encode,

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impl<T> EncodeLike<Rc<T>> for T
where T: Encode,

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impl<S> FullCodec for S
where S: Decode + FullEncode,

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impl<S> FullEncode for S
where S: Encode + EncodeLike,

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impl<T> JsonSchemaMaybe for T

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impl<T> StaticTypeInfo for T
where T: TypeInfo + 'static,