std::pin::Pin - Rust
Description: API documentation for the Rust `Pin` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, Pin

# [−][src]Struct std::pin::Pin

    pub struct Pin<P> { /* fields omitted */ }

🔬 This is a nightly-only experimental API. (`pin` #49150)

A pinned pointer.

This is a wrapper around a kind of pointer which makes that pointer "pin" its value in place, preventing the value referenced by that pointer from being moved unless it implements `Unpin`.

See the `pin` module documentation for furthur explanation on pinning.

## Methods

###

`impl<P> Pin<P> where P: Deref, <P as Deref>::Target: Unpin,`

[src]

####

`pub fn new(pointer: P) -> Pin<P>`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Construct a new `Pin` around a pointer to some data of a type that implements `Unpin`.

###

`impl<P> Pin<P> where P: Deref,`

[src]

####

`pub unsafe fn new_unchecked(pointer: P) -> Pin<P>`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Construct a new `Pin` around a reference to some data of a type that may or may not implement `Unpin`.

# Safety

This constructor is unsafe because we cannot guarantee that the data pointed to by `pointer` is pinned. If the constructed `Pin<P>` does not guarantee that the data `P` points to is pinned, constructing a `Pin<P>` is undefined behavior.

If `pointer` dereferences to an `Unpin` type, `Pin::new` should be used instead.

####

`pub fn as_ref(&self) -> Pin<&<P as Deref>::Target>`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Get a pinned shared reference from this pinned pointer.

###

`impl<P> Pin<P> where P: DerefMut,`

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####

`pub fn as_mut(&mut self) -> Pin<&mut <P as Deref>::Target>`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Get a pinned mutable reference from this pinned pointer.

####

`pub fn set(self, value: <P as Deref>::Target) where <P as Deref>::Target: Sized,`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Assign a new value to the memory behind the pinned reference.

###

`impl<'a, T> Pin<&'a T> where T: ?Sized,`

[src]

####

`pub unsafe fn map_unchecked<U, F>(this: Pin<&'a T>, func: F) -> Pin<&'a U> where F: FnOnce(&T) -> &U,`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Construct a new pin by mapping the interior value.

For example, if you wanted to get a `Pin` of a field of something, you could use this to get access to that field in one line of code.

# Safety

This function is unsafe. You must guarantee that the data you return will not move so long as the argument value does not move (for example, because it is one of the fields of that value), and also that you do not move out of the argument you receive to the interior function.

####
ⓘImportant traits for &'a mut I

### Important traits for &'a mut I

`impl<'a, I> Iterator for &'a mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'a, R: Read + ?Sized> Read for &'a mut Rimpl<'a, W: Write + ?Sized> Write for &'a mut W`

`pub fn get_ref(this: Pin<&'a T>) -> &'a T`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Get a shared reference out of a pin.

Note: `Pin` also implements `Deref` to the target, which can be used to access the inner value. However, `Deref` only provides a reference that lives for as long as the borrow of the `Pin`, not the lifetime of the `Pin` itself. This method allows turning the `Pin` into a reference with the same lifetime as the original `Pin`.

###

`impl<'a, T> Pin<&'a mut T> where T: ?Sized,`

[src]

####

`pub fn into_ref(this: Pin<&'a mut T>) -> Pin<&'a T>`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Convert this `Pin<&mut T>` into a `Pin<&T>` with the same lifetime.

####
ⓘImportant traits for &'a mut I

### Important traits for &'a mut I

`impl<'a, I> Iterator for &'a mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'a, R: Read + ?Sized> Read for &'a mut Rimpl<'a, W: Write + ?Sized> Write for &'a mut W`

`pub fn get_mut(this: Pin<&'a mut T>) -> &'a mut T where T: Unpin,`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Get a mutable reference to the data inside of this `Pin`.

This requires that the data inside this `Pin` is `Unpin`.

Note: `Pin` also implements `DerefMut` to the data, which can be used to access the inner value. However, `DerefMut` only provides a reference that lives for as long as the borrow of the `Pin`, not the lifetime of the `Pin` itself. This method allows turning the `Pin` into a reference with the same lifetime as the original `Pin`.

####
ⓘImportant traits for &'a mut I

### Important traits for &'a mut I

`impl<'a, I> Iterator for &'a mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'a, R: Read + ?Sized> Read for &'a mut Rimpl<'a, W: Write + ?Sized> Write for &'a mut W`

`pub unsafe fn get_mut_unchecked(this: Pin<&'a mut T>) -> &'a mut T`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Get a mutable reference to the data inside of this `Pin`.

# Safety

This function is unsafe. You must guarantee that you will never move the data out of the mutable reference you receive when you call this function, so that the invariants on the `Pin` type can be upheld.

If the underlying data is `Unpin`, `Pin::get_mut` should be used instead.

####

`pub unsafe fn map_unchecked_mut<U, F>( this: Pin<&'a mut T>, func: F ) -> Pin<&'a mut U> where F: FnOnce(&mut T) -> &mut U,`

[src]

🔬 This is a nightly-only experimental API. (`pin` #49150)

Construct a new pin by mapping the interior value.

For example, if you wanted to get a `Pin` of a field of something, you could use this to get access to that field in one line of code.

# Safety

This function is unsafe. You must guarantee that the data you return will not move so long as the argument value does not move (for example, because it is one of the fields of that value), and also that you do not move out of the argument you receive to the interior function.

## Trait Implementations

###

`impl<P> DerefMut for Pin<P> where P: DerefMut, <P as Deref>::Target: Unpin,`

[src]

####

`fn deref_mut(&mut self) -> &mut <P as Deref>::Target`

[src]

Mutably dereferences the value.

###

`impl<P> Hash for Pin<P> where P: Hash,`

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####

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

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Feeds this value into the given [`Hasher`]. Read more

####

`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<P> Deref for Pin<P> where P: Deref,`

[src]

#### `type Target = <P as Deref>::Target`

The resulting type after dereferencing.

####

`fn deref(&self) -> &<P as Deref>::Target`

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Dereferences the value.

###

`impl<P> Pointer for Pin<P> where P: Pointer,`

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####

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

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Formats the value using the given formatter.

###

`impl<P> Debug for Pin<P> where P: Debug,`

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####

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

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Formats the value using the given formatter. Read more

###

`impl<P> Clone for Pin<P> where P: Clone,`

[src]

####

`fn clone(&self) -> Pin<P>`

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Returns a copy of the value. Read more

####

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

1.0.0
[src]

Performs copy-assignment from `source`. Read more

###

`impl<P> PartialOrd<Pin<P>> for Pin<P> where P: PartialOrd<P>,`

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####

`fn partial_cmp(&self, other: &Pin<P>) -> Option<Ordering>`

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

####

`fn lt(&self, other: &Pin<P>) -> bool`

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

####

`fn le(&self, other: &Pin<P>) -> bool`

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

####

`fn gt(&self, other: &Pin<P>) -> bool`

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

####

`fn ge(&self, other: &Pin<P>) -> bool`

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

###

`impl<P> Ord for Pin<P> where P: Ord,`

[src]

####

`fn cmp(&self, other: &Pin<P>) -> Ordering`

[src]

This method returns an `Ordering` between `self` and `other`. Read more

####

`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

###

`impl<P> Future for Pin<P> where P: DerefMut, <P as Deref>::Target: Future,`

[src]

#### `type Output = <<P as Deref>::Target as Future>::Output`

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

futures in libcore are unstable

The result of the `Future`.

####

`fn poll( self: Pin<&mut Pin<P>>, lw: &LocalWaker ) -> Poll<<Pin<P> as Future>::Output>`

[src]

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

futures in libcore are unstable

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

###

`impl<P> Eq for Pin<P> where P: Eq,`

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###

`impl<P> PartialEq<Pin<P>> for Pin<P> where P: PartialEq<P>,`

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####

`fn eq(&self, other: &Pin<P>) -> bool`

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

####

`fn ne(&self, other: &Pin<P>) -> bool`

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This method tests for `!=`.

###

`impl<P, U> CoerceUnsized<Pin<U>> for Pin<P> where P: CoerceUnsized<U>,`

[src]

###

`impl<P> Copy for Pin<P> where P: Copy,`

[src]

###

`impl<P> Display for Pin<P> where P: Display,`

[src]

####

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

[src]

Formats the value using the given formatter. Read more

###

`impl<P> Unpin for Pin<P>`

[src]

###

`impl<T> From<Box<T>> for Pin<Box<T>>`

[src]

####

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

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Performs the conversion.

## Auto Trait Implementations

###

`impl<P> Send for Pin<P> where P: Send,`

###

`impl<P> Sync for Pin<P> where P: Sync,`

## Blanket Implementations

###

`impl<T> From for T`

[src]

####

`fn from(t: T) -> T`

[src]

Performs the conversion.

###

`impl<T, U> TryFrom for T where T: From<U>,`

[src]

#### `type Error = !`

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

####

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

[src]

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

###

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

[src]

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

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

####

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

[src]

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

###

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

[src]

####

`fn into(self) -> U`

[src]

Performs the conversion.

###

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

[src]

####
ⓘImportant traits for &'a mut I

### Important traits for &'a mut I

`impl<'a, I> Iterator for &'a mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'a, R: Read + ?Sized> Read for &'a mut Rimpl<'a, W: Write + ?Sized> Write for &'a mut W`

`fn borrow(&self) -> &T`

[src]

Immutably borrows from an owned value. Read more

###

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

[src]

####
ⓘImportant traits for &'a mut I

### Important traits for &'a mut I

`impl<'a, I> Iterator for &'a mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'a, R: Read + ?Sized> Read for &'a mut Rimpl<'a, W: Write + ?Sized> Write for &'a mut W`

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

[src]

Mutably borrows from an owned value. Read more

###

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

[src]

####

`fn get_type_id(&self) -> TypeId`

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🔬 This is a nightly-only experimental API. (`get_type_id` #27745)

this method will likely be replaced by an associated static

Gets the `TypeId` of `self`. Read more

###

`impl<T> ToOwned for T where T: Clone,`

[src]

#### `type Owned = T`

####

`fn to_owned(&self) -> T`

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Creates owned data from borrowed data, usually by cloning. Read more

####

`fn clone_into(&self, target: &mut T)`

[src]

🔬 This is a nightly-only experimental API. (`toowned_clone_into` #41263)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

###

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

[src]

####

`fn to_string(&self) -> String`

[src]

Converts the given value to a `String`. Read more

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