1.0.0[][src]Struct std::boxed::Box

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

A pointer type for heap allocation.

See the module-level documentation for more.

Methods

impl<T> Box<T>[src]

Important traits for Box<F>
pub fn new(x: T) -> Box<T>[src]

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

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

Examples

let five = Box::new(5);Run

Important traits for Pin<P>
pub fn pin(x: T) -> Pin<Box<T>>
1.33.0
[src]

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

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

Important traits for Box<F>
pub unsafe fn from_raw(raw: *mut T) -> Box<T>
1.4.0
[src]

Constructs a box from a raw pointer.

After calling this function, the raw pointer is owned by the resulting Box. Specifically, the Box destructor will call the destructor of T and free the allocated memory. Since the way Box allocates and releases memory is unspecified, the only valid pointer to pass to this function is the one taken from another Box via the Box::into_raw function.

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

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

pub fn into_raw(b: Box<T>) -> *mut T
1.4.0
[src]

Consumes the Box, returning a wrapped raw pointer.

The pointer will be properly aligned and non-null.

After calling this function, the caller is responsible for the memory previously managed by the Box. In particular, the caller should properly destroy T and release the memory. The proper way to do so is to convert the raw pointer 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(b) instead of b.into_raw(). This is so that there is no conflict with a method on the inner type.

Examples

let x = Box::new(5);
let ptr = Box::into_raw(x);Run

pub fn into_raw_non_null(b: Box<T>) -> NonNull<T>[src]

🔬 This is a nightly-only experimental API. (box_into_raw_non_null #47336)

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 proper 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

#![feature(box_into_raw_non_null)]

fn main() {
    let x = Box::new(5);
    let ptr = Box::into_raw_non_null(x);
}Run

Important traits for &'_ mut I
pub fn leak<'a>(b: Box<T>) -> &'a mut T where
    T: 'a, 
1.26.0
[src]

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

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

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

Examples

Simple usage:

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

Unsized data:

fn main() {
    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]);
}Run

Important traits for Pin<P>
pub fn into_pin(boxed: Box<T>) -> Pin<Box<T>>[src]

🔬 This is a nightly-only experimental API. (box_into_pin #0)

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

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

This is also available via From.

impl Box<dyn Any + 'static>[src]

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

Attempt to downcast the box to a concrete type.

Examples

use std::any::Any;

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

fn main() {
    let my_string = "Hello World".to_string();
    print_if_string(Box::new(my_string));
    print_if_string(Box::new(0i8));
}Run

impl Box<dyn Any + 'static + Send>[src]

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

Attempt to downcast the box to a concrete type.

Examples

use std::any::Any;

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

fn main() {
    let my_string = "Hello World".to_string();
    print_if_string(Box::new(my_string));
    print_if_string(Box::new(0i8));
}Run

Trait Implementations

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

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

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

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

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

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

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

fn nth_back(&mut self, n: usize) -> Option<Self::Item>[src]

🔬 This is a nightly-only experimental API. (iter_nth_back #56995)

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

fn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R where
    F: FnMut(B, Self::Item) -> R,
    R: Try<Ok = B>, 
1.27.0
[src]

This is the reverse version of [try_fold()]: it takes elements starting from the back of the iterator. Read more

fn rfold<B, F>(self, accum: B, f: F) -> B where
    F: FnMut(B, Self::Item) -> B, 
1.27.0
[src]

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

fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item> where
    P: FnMut(&Self::Item) -> bool
1.27.0
[src]

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

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

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

fn max(self, other: Self) -> Self
1.21.0
[src]

Compares and returns the maximum of two values. Read more

fn min(self, other: Self) -> Self
1.21.0
[src]

Compares and returns the minimum of two values. Read more

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

🔬 This is a nightly-only experimental API. (clamp #44095)

Returns max if self is greater than max, and min if self is less than min. Otherwise this will return self. Panics if min > max. Read more

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

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

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

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

Important traits for Box<F>
fn default() -> Box<T>[src]

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

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

impl Default for Box<str>
1.17.0
[src]

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

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

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

impl<G> Generator for Box<G> where
    G: Unpin + Generator + ?Sized
[src]

type Yield = <G as Generator>::Yield

🔬 This is a nightly-only experimental API. (generator_trait #43122)

The type of value this generator yields. Read more

type Return = <G as Generator>::Return

🔬 This is a nightly-only experimental API. (generator_trait #43122)

The type of value this generator returns. Read more

impl From<Box<str>> for String
1.18.0
[src]

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

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

Examples

Basic usage:

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

assert_eq!("hello world", s3)Run

impl<T> From<Box<T>> for Pin<Box<T>> where
    T: ?Sized
1.33.0
[src]

Important traits for Pin<P>
fn from(boxed: Box<T>) -> Pin<Box<T>>[src]

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

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

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

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

Important traits for Box<F>
fn from(slice: &[T]) -> Box<[T]>[src]

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

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

Examples

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

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

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

Important traits for Box<F>
fn from(t: T) -> Box<T>[src]

Converts a generic type T into a Box<T>

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

Examples

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

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

impl<T> From<Vec<T>> for Box<[T]>
1.20.0
[src]

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

Important traits for Box<F>
fn from(s: &str) -> Box<str>[src]

Converts a &str into a Box<str>

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

Examples

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

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

Important traits for Box<F>
fn from(s: String) -> Box<str>[src]

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

Examples

Basic usage:

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

assert_eq!("hello world", s3)Run

impl From<Box<str>> for Box<[u8]>
1.19.0
[src]

Important traits for Box<F>
fn from(s: Box<str>) -> Box<[u8]>[src]

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

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

Examples

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

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

assert_eq!(boxed_slice, boxed_str);Run

impl<T> From<Box<[T]>> for Vec<T>
1.18.0
[src]

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

impl<A> FromIterator<A> for Box<[A]>
1.32.0
[src]

impl<F> Future for Box<F> where
    F: Unpin + Future + ?Sized
[src]

type Output = <F as Future>::Output

🔬 This is a nightly-only experimental API. (futures_api #50547)

futures in libcore are unstable

The type of value produced on completion.

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

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

impl<T> Unpin for Box<T> where
    T: ?Sized
1.33.0
[src]

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

impl<'_, A, R> FnOnce<A> for Box<dyn FnBox<A, Output = R> + '_>[src]

type Output = R

The returned type after the call operator is used.

impl<'_, A, R> FnOnce<A> for Box<dyn FnBox<A, Output = R> + '_ + Send>[src]

type Output = R

The returned type after the call operator is used.

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

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher
1.3.0
[src]

Feeds a slice of this type into the given [Hasher]. Read more

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

type Item = <I as Iterator>::Item

The type of the elements being iterated over.

fn count(self) -> usize[src]

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

fn last(self) -> Option<Self::Item>[src]

Consumes the iterator, returning the last element. Read more

Important traits for StepBy<I>
fn step_by(self, step: usize) -> StepBy<Self>
1.28.0
[src]

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

Important traits for Chain<A, B>
fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator<Item = Self::Item>, 
[src]

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

Important traits for Zip<A, B>
fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator
[src]

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

Important traits for Map<I, F>
fn map<B, F>(self, f: F) -> Map<Self, F> where
    F: FnMut(Self::Item) -> B, 
[src]

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

fn for_each<F>(self, f: F) where
    F: FnMut(Self::Item), 
1.21.0
[src]

Calls a closure on each element of an iterator. Read more

Important traits for Filter<I, P>
fn filter<P>(self, predicate: P) -> Filter<Self, P> where
    P: FnMut(&Self::Item) -> bool
[src]

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

Important traits for FilterMap<I, F>
fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where
    F: FnMut(Self::Item) -> Option<B>, 
[src]

Creates an iterator that both filters and maps. Read more

Important traits for Enumerate<I>
fn enumerate(self) -> Enumerate<Self>[src]

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

Important traits for Peekable<I>
fn peekable(self) -> Peekable<Self>[src]

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

Important traits for SkipWhile<I, P>
fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool
[src]

Creates an iterator that [skip]s elements based on a predicate. Read more

Important traits for TakeWhile<I, P>
fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool
[src]

Creates an iterator that yields elements based on a predicate. Read more

Important traits for Skip<I>
fn skip(self, n: usize) -> Skip<Self>[src]

Creates an iterator that skips the first n elements. Read more

Important traits for Take<I>
fn take(self, n: usize) -> Take<Self>[src]

Creates an iterator that yields its first n elements. Read more

Important traits for Scan<I, St, F>
fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where
    F: FnMut(&mut St, Self::Item) -> Option<B>, 
[src]

An iterator adaptor similar to [fold] that holds internal state and produces a new iterator. Read more

Important traits for FlatMap<I, U, F>
fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
    F: FnMut(Self::Item) -> U,
    U: IntoIterator
[src]

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

Important traits for Flatten<I>
fn flatten(self) -> Flatten<Self> where
    Self::Item: IntoIterator
1.29.0
[src]

Creates an iterator that flattens nested structure. Read more

Important traits for Fuse<I>
fn fuse(self) -> Fuse<Self>[src]

Creates an iterator which ends after the first [None]. Read more

Important traits for Inspect<I, F>
fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnMut(&Self::Item), 
[src]

Do something with each element of an iterator, passing the value on. Read more

Important traits for &'_ mut I
fn by_ref(&mut self) -> &mut Self[src]

Borrows an iterator, rather than consuming it. Read more

#[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>, 
[src]

Transforms an iterator into a collection. Read more

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

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

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R where
    F: FnMut(B, Self::Item) -> R,
    R: Try<Ok = B>, 
1.27.0
[src]

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

fn try_for_each<F, R>(&mut self, f: F) -> R where
    F: FnMut(Self::Item) -> R,
    R: Try<Ok = ()>, 
1.27.0
[src]

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

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

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

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

Tests if every element of the iterator matches a predicate. Read more

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

Tests if any element of the iterator matches a predicate. Read more

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

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

fn find_map<B, F>(&mut self, f: F) -> Option<B> where
    F: FnMut(Self::Item) -> Option<B>, 
1.30.0
[src]

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

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

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

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

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

fn max(self) -> Option<Self::Item> where
    Self::Item: Ord
[src]

Returns the maximum element of an iterator. Read more

fn min(self) -> Option<Self::Item> where
    Self::Item: Ord
[src]

Returns the minimum element of an iterator. Read more

fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: FnMut(&Self::Item) -> B, 
1.6.0
[src]

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

fn max_by<F>(self, compare: F) -> Option<Self::Item> where
    F: FnMut(&Self::Item, &Self::Item) -> Ordering
1.15.0
[src]

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

fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: FnMut(&Self::Item) -> B, 
1.6.0
[src]

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

fn min_by<F>(self, compare: F) -> Option<Self::Item> where
    F: FnMut(&Self::Item, &Self::Item) -> Ordering
1.15.0
[src]

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

Important traits for Rev<I>
fn rev(self) -> Rev<Self> where
    Self: DoubleEndedIterator
[src]

Reverses an iterator's direction. Read more

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

Converts an iterator of pairs into a pair of containers. Read more

Important traits for Copied<I>
fn copied<'a, T>(self) -> Copied<Self> where
    Self: Iterator<Item = &'a T>,
    T: 'a + Copy
[src]

🔬 This is a nightly-only experimental API. (iter_copied #57127)

Creates an iterator which copies all of its elements. Read more

Important traits for Cloned<I>
fn cloned<'a, T>(self) -> Cloned<Self> where
    Self: Iterator<Item = &'a T>,
    T: 'a + Clone
[src]

Creates an iterator which [clone]s all of its elements. Read more

Important traits for Cycle<I>
fn cycle(self) -> Cycle<Self> where
    Self: Clone
[src]

Repeats an iterator endlessly. Read more

fn sum<S>(self) -> S where
    S: Sum<Self::Item>, 
1.11.0
[src]

Sums the elements of an iterator. Read more

fn product<P>(self) -> P where
    P: Product<Self::Item>, 
1.11.0
[src]

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

fn cmp<I>(self, other: I) -> Ordering where
    I: IntoIterator<Item = Self::Item>,
    Self::Item: Ord
1.5.0
[src]

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

fn partial_cmp<I>(self, other: I) -> Option<Ordering> where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 
1.5.0
[src]

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

fn eq<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 
1.5.0
[src]

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

fn ne<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 
1.5.0
[src]

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

fn lt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 
1.5.0
[src]

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

fn le<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 
1.5.0
[src]

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

fn gt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 
1.5.0
[src]

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

fn ge<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 
1.5.0
[src]

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

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

🔬 This is a nightly-only experimental API. (is_sorted #53485)

new API

Checks if the elements of this iterator are sorted. Read more

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

🔬 This is a nightly-only experimental API. (is_sorted #53485)

new API

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

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

🔬 This is a nightly-only experimental API. (is_sorted #53485)

new API

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

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

type Target = T

The resulting type after dereferencing.

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

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

Important traits for Box<F>
fn clone(&self) -> Box<T>[src]

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

Examples

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

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

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

Examples

let x = Box::new(5);
let mut y = Box::new(10);

y.clone_from(&x);

assert_eq!(*y, 5);Run

impl<T> Clone for Box<[T]> where
    T: Clone
1.3.0
[src]

fn clone_from(&mut self, source: &Self)[src]

Performs copy-assignment from source. Read more

impl Clone for Box<str>
1.3.0
[src]

fn clone_from(&mut self, source: &Self)[src]

Performs copy-assignment from source. Read more

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

fn source(&self) -> Option<&(dyn Error + 'static)>
1.30.0
[src]

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

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

Important traits for &'_ mut I
fn by_ref(&mut self) -> &mut Self where
    Self: Sized
[src]

Creates a "by reference" adaptor for this instance of Read. Read more

Important traits for Bytes<R>
fn bytes(self) -> Bytes<Self> where
    Self: Sized
[src]

Transforms this Read instance to an [Iterator] over its bytes. Read more

Important traits for Chain<T, U>
fn chain<R: Read>(self, next: R) -> Chain<Self, R> where
    Self: Sized
[src]

Creates an adaptor which will chain this stream with another. Read more

Important traits for Take<T>
fn take(self, limit: u64) -> Take<Self> where
    Self: Sized
[src]

Creates an adaptor which will read at most limit bytes from it. Read more

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

Important traits for &'_ mut I
fn by_ref(&mut self) -> &mut Self where
    Self: Sized
[src]

Creates a "by reference" adaptor for this instance of Write. Read more

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

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

Important traits for Split<B>
fn split(self, byte: u8) -> Split<Self> where
    Self: Sized
[src]

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

Important traits for Lines<B>
fn lines(self) -> Lines<Self> where
    Self: Sized
[src]

Returns an iterator over the lines of this reader. Read more

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

Important traits for Box<F>
fn from(err: E) -> Box<dyn Error + 'a>[src]

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

Examples

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

#[derive(Debug)]
struct AnError;

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

impl Error for AnError {
    fn description(&self) -> &str {
        "Description of an error"
    }
}

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

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

Important traits for Box<F>
fn from(err: E) -> Box<dyn Error + Send + Sync + 'a>[src]

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

Examples

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

#[derive(Debug)]
struct AnError;

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

impl Error for AnError {
    fn description(&self) -> &str {
        "Description of an error"
    }
}

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

impl From<String> for Box<dyn Error + Send + Sync>[src]

Important traits for Box<F>
fn from(err: String) -> Box<dyn Error + Send + Sync>[src]

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

Examples

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

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

impl From<String> for Box<dyn Error>
1.6.0
[src]

Important traits for Box<F>
fn from(str_err: String) -> Box<dyn Error>[src]

Converts a String into a box of dyn Error.

Examples

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

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

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

Important traits for Box<F>
fn from(err: &str) -> Box<dyn Error + Send + Sync + 'a>[src]

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

Examples

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

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

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

Important traits for Box<F>
fn from(err: &str) -> Box<dyn Error>[src]

Converts a str into a box of dyn Error.

Examples

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

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

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

Important traits for Box<F>
fn from(err: Cow<'b, str>) -> Box<dyn Error + Send + Sync + 'a>[src]

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

Examples

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

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

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

Important traits for Box<F>
fn from(err: Cow<'a, str>) -> Box<dyn Error>[src]

Converts a Cow into a box of dyn Error.

Examples

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

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

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

impl From<Box<CStr>> for CString
1.18.0
[src]

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

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

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

Important traits for Box<F>
fn from(s: CString) -> Box<CStr>[src]

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

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

impl From<Box<OsStr>> for OsString
1.18.0
[src]

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

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

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

Important traits for Box<F>
fn from(s: OsString) -> Box<OsStr>[src]

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

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

impl From<Box<Path>> for PathBuf
1.18.0
[src]

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

Converts a Box<Path> into a PathBuf

This conversion does not allocate or copy memory.

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

Important traits for Box<F>
fn from(p: PathBuf) -> Box<Path>[src]

Converts a PathBuf into a Box<Path>

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

impl Clone for Box<CStr>
1.29.0
[src]

fn clone_from(&mut self, source: &Self)[src]

Performs copy-assignment from source. Read more

impl Clone for Box<OsStr>
1.29.0
[src]

fn clone_from(&mut self, source: &Self)[src]

Performs copy-assignment from source. Read more

impl Clone for Box<Path>
1.29.0
[src]

fn clone_from(&mut self, source: &Self)[src]

Performs copy-assignment from source. Read more

impl Default for Box<CStr>
1.17.0
[src]

impl Default for Box<OsStr>
1.17.0
[src]

Auto Trait Implementations

impl<T: ?Sized> Send for Box<T> where
    T: Send

impl<T: ?Sized> Sync for Box<T> where
    T: Sync

Blanket Implementations

impl<T> From for T[src]

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

type Item = <I as Iterator>::Item

The type of the elements being iterated over.

type IntoIter = I

Which kind of iterator are we turning this into?

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

type Error = Infallible

The type returned in the event of a conversion error.

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

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

The type returned in the event of a conversion error.

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

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

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

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

impl<A, F> FnBox for F where
    F: FnOnce<A>, 
[src]

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

🔬 This is a nightly-only experimental API. (fnbox #28796)

will be deprecated if and when Box<FnOnce> becomes usable

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

type Owned = T

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