Struct alloc_wg::boxed::Box

pub struct Box<T: ?Sized, A: AllocRef = Global> { /* fields omitted */ }

A pointer type for heap allocation.

See the module-level documentation for more.

Implementations

impl<T> Box<T>

#[must_use]pub fn new(x: T) -> Self

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

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

Example

use alloc_wg::boxed::Box;

let five = Box::new(5);

#[must_use]pub fn new_uninit() -> Box<MaybeUninit<T>>

Constructs a new box with uninitialized contents.

Example

use alloc_wg::boxed::Box;

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

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

    five.assume_init()
};

assert_eq!(*five, 5)

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

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

impl<T, A: AllocRef> Box<T, A>

pub fn new_in(x: T, a: A) -> Self

Allocates memory with the given allocator and then places x into it.

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

Example

#![feature(allocator_api)]
use alloc_wg::{alloc::Global, boxed::Box};

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

pub fn try_new_in(x: T, alloc: A) -> Result<Self, AllocErr>

Tries to allocate memory with the given allocator and then places x into it.

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

Example

#![feature(allocator_api)]
use alloc_wg::{alloc::Global, boxed::Box};

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

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

Constructs a new box with uninitialized contents in a specified allocator.

Example

#![feature(allocator_api)]
use alloc_wg::{alloc::Global, boxed::Box};

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

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

    five.assume_init()
};

assert_eq!(*five, 5)

pub fn try_new_uninit_in(alloc: A) -> Result<Box<MaybeUninit<T>, A>, AllocErr>

Tries to construct a new box with uninitialized contents in a specified allocator.

Example

#![feature(allocator_api)]
use alloc_wg::{alloc::Global, boxed::Box};

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

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

    five.assume_init()
};

assert_eq!(*five, 5);

pub fn pin_in(x: T, a: A) -> Pin<Self>

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

pub fn try_pin_in(x: T, a: A) -> Result<Pin<Self>, AllocErr>

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

impl<T> Box<[T]>

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

Construct a new boxed slice with uninitialized contents.

Example

use alloc_wg::boxed::Box;

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

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

    values.assume_init()
};

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

impl<T, A: AllocRef> Box<[T], A>

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

Construct a new boxed slice with uninitialized contents with the spoecified allocator.

Example

#![feature(allocator_api)]
use alloc_wg::{alloc::Global, boxed::Box};

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

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

    values.assume_init()
};

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

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

Tries to construct a new boxed slice with uninitialized contents with the spoecified allocator.

Example

#![feature(allocator_api)]
use alloc_wg::{alloc::Global, boxed::Box};

let mut values = Box::<[u32], Global>::try_new_uninit_slice_in(3, Global)?;

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

    values.assume_init()
};

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

impl<T, A: AllocRef> Box<MaybeUninit<T>, A>

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

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.

Example

use alloc_wg::boxed::Box;

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)

impl<T, A: AllocRef> Box<[MaybeUninit<T>], A>

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

Converts to Box<[T], B>.

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.

Example

use alloc_wg::boxed::Box;

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

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

    values.assume_init()
};

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

impl<T: ?Sized> Box<T>

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

Constructs a box from a raw pointer.

After calling this function, the raw pointer is owned by the resulting Box.2 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:

use alloc_wg::boxed::Box;

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 alloc_wg::{alloc::alloc, boxed::Box};
use core::alloc::Layout;

unsafe {
    let ptr = alloc(Layout::new::<i32>()) as *mut i32;
    *ptr = 5;
    let x = Box::from_raw(ptr);
}

impl<T: ?Sized, A: AllocRef> Box<T, A>

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

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.

Example

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

#![feature(allocator_api)]
use alloc_wg::{
    alloc::{alloc, Global},
    boxed::Box,
};
use core::alloc::Layout;

unsafe {
    let ptr = alloc(Layout::new::<i32>()) as *mut i32;
    *ptr = 5;
    let x: Box<_, Global> = Box::from_raw_in(ptr, Global);
}

pub fn build_alloc(&self) -> &A

Returns a shared reference to the associated BuildAlloc

pub fn build_alloc_mut(&mut self) -> &mut A

Returns a mutable reference to the associated BuildAlloc

pub fn alloc_ref(&self) -> &A

Returns a shared reference to the allocator.

pub fn alloc_ref_mut(&mut self) -> &mut A

Returns a mutable reference to the allocator.

pub fn into_raw(b: Self) -> *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:

use alloc_wg::boxed::Box;

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 alloc_wg::{alloc::dealloc, boxed::Box};
use core::{alloc::Layout, ptr};

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

pub fn into_raw_alloc(b: Self) -> (*mut T, A)

pub fn into_raw_non_null(b: Self) -> NonNull<T>

Consumes the Box, returning the wrapped pointer as NonNull<T>.

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. The easiest way to do so is to convert the NonNull<T> pointer into a raw pointer and back into a Box with the Box::from_raw function.

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

Examples

use alloc_wg::boxed::Box;

let x = Box::new(5);
let ptr = Box::into_raw_non_null(x);

// Clean up the memory by converting the NonNull pointer back
// into a Box and letting the Box be dropped.
let x = unsafe { Box::from_raw(ptr.as_ptr()) };

pub fn into_raw_non_null_alloc(b: Self) -> (NonNull<T>, A)

pub fn leak<'a>(b: Self) -> &'a mut T where
    T: '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:

use alloc_wg::boxed::Box;

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

pub fn into_pin(boxed: Self) -> Pin<Self>

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

This conversion does not allocate and happens in place.

This is also available via From.

impl<A: AllocRef> Box<dyn Any, A>

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

Attempt to downcast the box to a concrete type.

Examples

use std::any::Any;

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

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

impl<A: AllocRef> Box<dyn Any + Send, A>

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

Attempt to downcast the box to a concrete type.

Examples

use std::any::Any;

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

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

Trait Implementations

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

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

Performs the conversion.

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

fn as_ref(&self) -> &T

Performs the conversion.

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

fn borrow(&self) -> &T

Immutably borrows from an owned value.

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

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

Mutably borrows from an owned value.

impl<T: Clone, A: AllocRef + Clone> Clone for Box<T, A>

fn clone(&self) -> Self

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

Examples

use alloc_wg::boxed::Box;

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

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

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

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

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

Examples

use alloc_wg::boxed::Box;

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

y.clone_from(&x);

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

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

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

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Clone, A: AllocRef, B: AllocRef> CloneIn<B> for Box<T, A>

type Cloned = Box<T, B>

fn clone_in(&self, a: B) -> Self::Cloned

fn try_clone_in(&self, a: B) -> Result<Self::Cloned, TryReserveError>

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

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

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

Formats the value using the given formatter.

impl<T, A> Default for Box<T, A> where
    T: Default,
    A: Default + AllocRef, 

#[must_use]fn default() -> Self

Returns the "default value" for a type.

impl<T, A: AllocRef> Default for Box<[T], A> where
    A: Default, 

#[must_use]fn default() -> Self

Returns the "default value" for a type.

impl<A> Default for Box<str, A> where
    A: Default + AllocRef, 

#[must_use]fn default() -> Self

Returns the "default value" for a type.

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

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

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

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

Mutably dereferences the value.

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

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

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

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

Formats the value using the given formatter.

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

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

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

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

Returns the nth element from the end of the iterator.

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

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

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

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

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

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

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

fn drop(&mut self)

Executes the destructor for this type.

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

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

fn len(&self) -> usize

Returns the exact length of the iterator.

fn is_empty(&self) -> bool

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

Returns true if the iterator is empty.

impl<Args, F: Fn<Args> + Copy + ?Sized, A: AllocRef> Fn<Args> for Box<F, A>

extern "rust-call" fn call(&self, args: Args) -> Self::Output

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

Performs the call operation.

impl<Args, F: FnMut<Args> + Copy + ?Sized, A: AllocRef> FnMut<Args> for Box<F, A>

extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output

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

Performs the call operation.

impl<Args, F: FnOnce<Args> + Copy + ?Sized, A: AllocRef> FnOnce<Args> for Box<F, A>

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

The returned type after the call operator is used.

extern "rust-call" fn call_once(self, args: Args) -> Self::Output

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

Performs the call operation.

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

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

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

This conversion allocates and performs a copy of slice.

Examples

use alloc_wg::boxed::Box;

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

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

impl<A: AllocRef, '_> From<&'_ str> for Box<str, A> where
    A: Default, 

#[must_use]fn from(s: &str) -> Self

Converts a &str into a Box<str>

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

Examples

use alloc_wg::boxed::Box;

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

impl<T: ?Sized, A: AllocRef> From<Box<T, A>> for Pin<Box<T, A>>

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

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

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

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

fn from(s: Box<str, A>) -> Self

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

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

Examples

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

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

assert_eq!(boxed_slice, boxed_str);

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

#[must_use]fn from(s: Box<str>) -> Self

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

Examples

Basic usage:

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

assert_eq!("hello world", s3)

impl<A> From<String<A>> for Box<str, A> where
    A: AllocRef, 

fn from(s: String<A>) -> Self

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

Examples

Basic usage:

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

assert_eq!("hello world", s3)

impl<T, A> From<T> for Box<T, A> where
    A: Default + AllocRef, 

fn from(t: T) -> Self

Converts a generic type T into a Box<T>

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

Examples

use alloc_wg::boxed::Box;

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

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

impl<T> From<Vec<T, Global>> for Box<[T]>

#[must_use]fn from(v: Vec<T>) -> Self

Performs the conversion.

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

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

type Output = F::Output

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>

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

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

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

Feeds this value into the given Hasher.

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

Feeds a slice of this type into the given Hasher.

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

fn finish(&self) -> u64

Returns the hash value for the values written so far.

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

Writes some data into this Hasher.

fn write_u8(&mut self, i: u8)

Writes a single u8 into this hasher.

fn write_u16(&mut self, i: u16)

Writes a single u16 into this hasher.

fn write_u32(&mut self, i: u32)

Writes a single u32 into this hasher.

fn write_u64(&mut self, i: u64)

Writes a single u64 into this hasher.

fn write_u128(&mut self, i: u128)

Writes a single u128 into this hasher.

fn write_usize(&mut self, i: usize)

Writes a single usize into this hasher.

fn write_i8(&mut self, i: i8)

Writes a single i8 into this hasher.

fn write_i16(&mut self, i: i16)

Writes a single i16 into this hasher.

fn write_i32(&mut self, i: i32)

Writes a single i32 into this hasher.

fn write_i64(&mut self, i: i64)

Writes a single i64 into this hasher.

fn write_i128(&mut self, i: i128)

Writes a single i128 into this hasher.

fn write_isize(&mut self, i: isize)

Writes a single isize into this hasher.

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

type Item = I::Item

The type of the elements being iterated over.

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

Advances the iterator and returns the next value.

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

Returns the bounds on the remaining length of the iterator.

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

Consumes the iterator, returning the last element.

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

Returns the nth element of the iterator.

fn count(self) -> usize

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

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

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

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

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

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

'Zips up' two iterators into a single iterator of pairs.

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

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

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

Calls a closure on each element of an iterator.

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

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

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

Creates an iterator that both filters and maps.

fn enumerate(self) -> Enumerate<Self>

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

fn peekable(self) -> Peekable<Self>

Creates an iterator which can use peek to look at the next element of the iterator without consuming it.

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

Creates an iterator that skips elements based on a predicate.

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

Creates an iterator that yields elements based on a predicate.

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

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

recently added

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

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

Creates an iterator that skips the first n elements.

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

Creates an iterator that yields its first n elements.

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

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

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

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

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

Creates an iterator that flattens nested structure.

fn fuse(self) -> Fuse<Self>

Creates an iterator which ends after the first None.

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

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

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

Borrows an iterator, rather than consuming it.

#[must_use = "if you really need to exhaust the iterator, consider `.for_each(drop)` instead"]fn collect<B>(self) -> B where
    B: FromIterator<Self::Item>, 

Transforms an iterator into a collection.

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

Consumes an iterator, creating two collections from it.

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

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

new API

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

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

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

new API

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

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

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

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

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

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

An iterator method that applies a function, producing a single, final value.

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

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

The same as fold(), but uses the first element in the iterator as the initial value, folding every subsequent element into it. If the iterator is empty, return None; otherwise, return the result of the fold.

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

Tests if every element of the iterator matches a predicate.

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

Tests if any element of the iterator matches a predicate.

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

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

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

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

fn try_find<F, R>(
    &mut self,
    f: F
) -> Result<Option<Self::Item>, <R as Try>::Error> where
    F: FnMut(&Self::Item) -> R,
    R: Try<Ok = bool>, 

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

new API

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

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

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

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

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

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

Returns the maximum element of an iterator.

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

Returns the minimum element of an iterator.

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

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

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

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

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

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

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

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

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

Reverses an iterator's direction.

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

Converts an iterator of pairs into a pair of containers.

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

Creates an iterator which copies all of its elements.

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

Creates an iterator which clones all of its elements.

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

Repeats an iterator endlessly.

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

Sums the elements of an iterator.

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

Iterates over the entire iterator, multiplying all the elements

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

new API

Checks if the elements of this iterator are sorted.

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

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

new API

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

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

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

new API

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

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

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

#[must_use]fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]fn clamp(self, min: Self, max: Self) -> Self

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

Restrict a value to a certain interval.

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

fn eq(&self, other: &Self) -> bool

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

fn ne(&self, other: &Self) -> bool

This method tests for !=.

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

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

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

fn lt(&self, other: &Self) -> bool

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

fn le(&self, other: &Self) -> bool

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

fn gt(&self, other: &Self) -> bool

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

fn ge(&self, other: &Self) -> bool

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

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

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

Formats the value using the given formatter.

impl<T: ?Sized, A: AllocRef> Receiver for Box<T, A>

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

type Error = Box<[T]>

The type returned in the event of a conversion error.

fn try_from(boxed_slice: Box<[T]>) -> Result<Self, Self::Error>

Performs the conversion.

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