Struct tracing_core::stdlib::boxed::ThinBox

source ·
pub struct ThinBox<T>
where T: ?Sized,
{ ptr: WithOpaqueHeader, _marker: PhantomData<T>, }
🔬This is a nightly-only experimental API. (thin_box #92791)
Expand description

ThinBox.

A thin pointer for heap allocation, regardless of T.

§Examples

#![feature(thin_box)]
use std::boxed::ThinBox;

let five = ThinBox::new(5);
let thin_slice = ThinBox::<[i32]>::new_unsize([1, 2, 3, 4]);

use std::mem::{size_of, size_of_val};
let size_of_ptr = size_of::<*const ()>();
assert_eq!(size_of_ptr, size_of_val(&five));
assert_eq!(size_of_ptr, size_of_val(&thin_slice));

Fields§

§ptr: WithOpaqueHeader
🔬This is a nightly-only experimental API. (thin_box #92791)
§_marker: PhantomData<T>
🔬This is a nightly-only experimental API. (thin_box #92791)

Implementations§

source§

impl<T> ThinBox<T>

source

pub fn new(value: T) -> ThinBox<T>

🔬This is a nightly-only experimental API. (thin_box #92791)

Moves a type to the heap with its Metadata stored in the heap allocation instead of on the stack.

§Examples
#![feature(thin_box)]
use std::boxed::ThinBox;

let five = ThinBox::new(5);
source

pub fn try_new(value: T) -> Result<ThinBox<T>, AllocError>

🔬This is a nightly-only experimental API. (thin_box #92791)

Moves a type to the heap with its Metadata stored in the heap allocation instead of on the stack. Returns an error if allocation fails, instead of aborting.

§Examples
#![feature(allocator_api)]
#![feature(thin_box)]
use std::boxed::ThinBox;

let five = ThinBox::try_new(5)?;
source§

impl<Dyn> ThinBox<Dyn>
where Dyn: ?Sized,

source

pub fn new_unsize<T>(value: T) -> ThinBox<Dyn>
where T: Unsize<Dyn>,

🔬This is a nightly-only experimental API. (thin_box #92791)

Moves a type to the heap with its Metadata stored in the heap allocation instead of on the stack.

§Examples
#![feature(thin_box)]
use std::boxed::ThinBox;

let thin_slice = ThinBox::<[i32]>::new_unsize([1, 2, 3, 4]);

Trait Implementations§

source§

impl<T> Debug for ThinBox<T>
where T: Debug + ?Sized,

source§

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

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

impl<T> Deref for ThinBox<T>
where T: ?Sized,

§

type Target = T

The resulting type after dereferencing.
source§

fn deref(&self) -> &T

Dereferences the value.
source§

impl<T> DerefMut for ThinBox<T>
where T: ?Sized,

source§

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

Mutably dereferences the value.
source§

impl<T> Display for ThinBox<T>
where T: Display + ?Sized,

source§

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

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

impl<T> Drop for ThinBox<T>
where T: ?Sized,

source§

fn drop(&mut self)

Executes the destructor for this type. Read more
source§

impl<T> Error for ThinBox<T>
where T: Error + ?Sized,

source§

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

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

fn description(&self) -> &str

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

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

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

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

🔬This is a nightly-only experimental API. (error_generic_member_access #99301)
Provides type based access to context intended for error reports. Read more
source§

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

ThinBox<T> is Send if T is Send because the data is owned.

source§

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

ThinBox<T> is Sync if T is Sync because the data is owned.

Auto Trait Implementations§

§

impl<T> Freeze for ThinBox<T>
where T: ?Sized,

§

impl<T> RefUnwindSafe for ThinBox<T>
where T: RefUnwindSafe + ?Sized,

§

impl<T> Unpin for ThinBox<T>
where T: Unpin + ?Sized,

§

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

Blanket Implementations§

source§

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

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

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

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

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

source§

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

Mutably borrows from an owned value. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T, U> Into<U> for T
where U: From<T>,

source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

source§

impl<T> ToString for T
where T: Display + ?Sized,

source§

default fn to_string(&self) -> String

Converts the given value to a String. Read more
source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

§

type Error = Infallible

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

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

§

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

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

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.