reference - Rust
Description: API documentation for the Rust `reference` primitive in crate `std`.
Keywords: rust, rustlang, rust-lang, reference

# Primitive Type reference 1.0.0 [−]

References, both shared and mutable.

A reference represents a borrow of some owned value. You can get one by using the `&` or `&mut` operators on a value, or by using a `ref` or `ref mut` pattern.

For those familiar with pointers, a reference is just a pointer that is assumed to not be null. In fact, `Option<&T>` has the same memory representation as a nullable pointer, and can be passed across FFI boundaries as such.

In most cases, references can be used much like the original value. Field access, method calling, and indexing work the same (save for mutability rules, of course). In addition, the comparison operators transparently defer to the referent's implementation, allowing references to be compared the same as owned values.

References have a lifetime attached to them, which represents the scope for which the borrow is valid. A lifetime is said to "outlive" another one if its representative scope is as long or longer than the other. The `'static` lifetime is the longest lifetime, which represents the total life of the program. For example, string literals have a `'static` lifetime because the text data is embedded into the binary of the program, rather than in an allocation that needs to be dynamically managed.

`&mut T` references can be freely coerced into `&T` references with the same referent type, and references with longer lifetimes can be freely coerced into references with shorter ones.

For more information on how to use references, see the book's section on "References and Borrowing".

The following traits are implemented for all `&T`, regardless of the type of its referent:

- `Copy`
- `Clone` (Note that this will not defer to `T`'s `Clone` implementation if it exists!)
- `Deref`
- `Borrow`
- `Pointer`

`&mut T` references get all of the above except `Copy` and `Clone` (to prevent creating multiple simultaneous mutable borrows), plus the following, regardless of the type of its referent:

- `DerefMut`
- `BorrowMut`

The following traits are implemented on `&T` references if the underlying `T` also implements that trait:

- All the traits in `std::fmt` except `Pointer` and `fmt::Write`
- `PartialOrd`
- `Ord`
- `PartialEq`
- `Eq`
- `AsRef`
- `Fn` (in addition, `&T` references get `FnMut` and `FnOnce` if `T: Fn`)
- `Hash`
- `ToSocketAddrs`

`&mut T` references get all of the above except `ToSocketAddrs`, plus the following, if `T` implements that trait:

- `AsMut`
- `FnMut` (in addition, `&mut T` references get `FnOnce` if `T: FnMut`)
- `fmt::Write`
- `Iterator`
- `DoubleEndedIterator`
- `ExactSizeIterator`
- `FusedIterator`
- `TrustedLen`
- `Send` (note that `&T` references only get `Send` if `T: Sync`)
- `io::Write`
- `Read`
- `Seek`
- `BufRead`

Note that due to method call deref coercion, simply calling a trait method will act like they work on references as well as they do on owned values! The implementations described here are meant for generic contexts, where the final type `T` is a type parameter or otherwise not locally known.

## Trait Implementations

### `impl<'a, T, U> AsRef<U> for &'a mut T where
T: AsRef<U> + ?Sized,
U: ?Sized,`
[src]

#### `fn as_ref(&self) -> &U`
[src]

Performs the conversion.

### `impl<'a, T, U> AsRef<U> for &'a T where
T: AsRef<U> + ?Sized,
U: ?Sized,`
[src]

#### `fn as_ref(&self) -> &U`
[src]

Performs the conversion.

### `impl<'a, T> UpperHex for &'a mut T where
T: UpperHex + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> UpperHex for &'a T where
T: UpperHex + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, I> ExactSizeIterator for &'a mut I where
I: ExactSizeIterator + ?Sized,`
[src]

#### `fn len(&self) -> usize`
[src]

Returns the exact number of times the iterator will iterate. Read more

#### `fn is_empty(&self) -> bool`
[src]

🔬 This is a nightly-only experimental API. (`exact_size_is_empty` #35428)

Returns whether the iterator is empty. Read more

### `impl<'a, T> LowerHex for &'a T where
T: LowerHex + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> LowerHex for &'a mut T where
T: LowerHex + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, A> Eq for &'a mut A where
A: Eq + ?Sized,`
[src]

### `impl<'a, A> Eq for &'a A where
A: Eq + ?Sized,`
[src]

### `impl<'a, W> Write for &'a mut W where
W: Write + ?Sized,`
1.4.0
[src]

#### `fn write_str(&mut self, s: &str) -> Result<(), Error>`
[src]

Writes a slice of bytes into this writer, returning whether the write succeeded. Read more

#### `fn write_char(&mut self, c: char) -> Result<(), Error>`
[src]

Writes a [`char`] into this writer, returning whether the write succeeded. Read more

#### `fn write_fmt(&mut self, args: Arguments) -> Result<(), Error>`
[src]

Glue for usage of the [`write!`] macro with implementors of this trait. Read more

### `impl<'a, T> Binary for &'a mut T where
T: Binary + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> Binary for &'a T where
T: Binary + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> Deref for &'a T where
T: ?Sized,`
[src]

#### `type Target = T`

The resulting type after dereferencing.

#### `fn deref(&self) -> &T`
[src]

Dereferences the value.

### `impl<'a, T> Deref for &'a mut T where
T: ?Sized,`
[src]

#### `type Target = T`

The resulting type after dereferencing.

#### `fn deref(&self) -> &T`
[src]

Dereferences the value.

### `impl<'a, T> DerefMut for &'a mut T where
T: ?Sized,`
[src]

#### `fn deref_mut(&mut self) -> &mut T`
[src]

Mutably dereferences the value.

### `impl<'a, T> Octal for &'a T where
T: Octal + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> Octal for &'a mut T where
T: Octal + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> BorrowMut<T> for &'a mut T where
T: ?Sized,`
[src]

#### `fn borrow_mut(&mut self) -> &mut T`
[src]

Mutably borrows from an owned value. Read more

### `impl<'a, T> Display for &'a mut T where
T: Display + ?Sized,`
[src]

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

Formats the value using the given formatter. Read more

### `impl<'a, T> Display for &'a T where
T: Display + ?Sized,`
[src]

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

Formats the value using the given formatter. Read more

### `impl<'a, T> Borrow<T> for &'a T where
T: ?Sized,`
[src]

#### `fn borrow(&self) -> &T`
[src]

Immutably borrows from an owned value. Read more

### `impl<'a, T> Borrow<T> for &'a mut T where
T: ?Sized,`
[src]

#### `fn borrow(&self) -> &T`
[src]

Immutably borrows from an owned value. Read more

### `impl<'a, T> Send for &'a mut T where
T: Send + ?Sized,`
[src]

### `impl<'a, T> Send for &'a T where
T: Sync + ?Sized,`
[src]

### `impl<'a, T> Debug for &'a mut T where
T: Debug + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> Debug for &'a T where
T: Debug + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, A, F> FnOnce<A> for &'a F where
F: Fn<A> + ?Sized,`
[src]

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

The returned type after the call operator is used.

#### `extern "rust-call" fn call_once(self, args: A) -> <F as FnOnce<A>>::Output`
[src]

🔬 This is a nightly-only experimental API. (`fn_traits` #29625)

Performs the call operation.

### `impl<'a, A, F> FnOnce<A> for &'a mut F where
F: FnMut<A> + ?Sized,`
[src]

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

The returned type after the call operator is used.

#### `extern "rust-call" fn call_once(self, args: A) -> <F as FnOnce<A>>::Output`
[src]

🔬 This is a nightly-only experimental API. (`fn_traits` #29625)

Performs the call operation.

### `impl<'a, I> TrustedLen for &'a mut I where
I: TrustedLen + ?Sized,`
[src]

### `impl<'a, T> UpperExp for &'a T where
T: UpperExp + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> UpperExp for &'a mut T where
T: UpperExp + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, I> Iterator for &'a mut I where
I: Iterator + ?Sized,`
[src]

#### `type Item = <I as Iterator>::Item`

The type of the elements being iterated over.

#### `fn next(&mut self) -> Option<<I as Iterator>::Item>`
[src]

Advances the iterator and returns the next value. Read more

#### `fn size_hint(&self) -> (usize, Option<usize>)`
[src]

Returns the bounds on the remaining length of the iterator. Read more

#### `fn nth(&mut self, n: usize) -> Option<<&'a mut I as Iterator>::Item>`
[src]

Returns the `n`th element of the iterator. Read more

#### `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

#### `fn step_by(self, step: usize) -> StepBy<Self>`
[src]

🔬 This is a nightly-only experimental API. (`iterator_step_by` #27741)

unstable replacement of Range::step_by

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

#### `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

#### `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

#### `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

#### `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

#### `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

#### `fn enumerate(self) -> Enumerate<Self>`
[src]

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

#### `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

#### `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

#### `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

#### `fn skip(self, n: usize) -> Skip<Self>`
[src]

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

#### `fn take(self, n: usize) -> Take<Self>`
[src]

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

#### `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

#### `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

#### `fn fuse(self) -> Fuse<Self>`
[src]

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

#### `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

#### `fn by_ref(&mut self) -> &mut Self`
[src]

Borrows an iterator, rather than consuming it. Read more

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

An iterator adaptor 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 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

#### `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

#### `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

#### `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

### `impl<'a, I> FusedIterator for &'a mut I where
I: FusedIterator + ?Sized,`
[src]

### `impl<'a, A, F> FnMut<A> for &'a F where
F: Fn<A> + ?Sized,`
[src]

#### `extern "rust-call" fn call_mut(&mut self, args: A) -> <F as FnOnce<A>>::Output`
[src]

🔬 This is a nightly-only experimental API. (`fn_traits` #29625)

Performs the call operation.

### `impl<'a, A, F> FnMut<A> for &'a mut F where
F: FnMut<A> + ?Sized,`
[src]

#### `extern "rust-call" fn call_mut(&mut self, args: A) -> <F as FnOnce<A>>::Output`
[src]

🔬 This is a nightly-only experimental API. (`fn_traits` #29625)

Performs the call operation.

### `impl<'a, 'b, A, B> PartialEq<&'b B> for &'a mut A where
A: PartialEq<B> + ?Sized,
B: ?Sized,`
[src]

#### `fn eq(&self, other: &&'b B) -> bool`
[src]

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

#### `fn ne(&self, other: &&'b B) -> bool`
[src]

This method tests for `!=`.

### `impl<'a, 'b, A, B> PartialEq<&'b B> for &'a A where
A: PartialEq<B> + ?Sized,
B: ?Sized,`
[src]

#### `fn eq(&self, other: &&'b B) -> bool`
[src]

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

#### `fn ne(&self, other: &&'b B) -> bool`
[src]

This method tests for `!=`.

### `impl<'a, 'b, A, B> PartialEq<&'b mut B> for &'a mut A where
A: PartialEq<B> + ?Sized,
B: ?Sized,`
[src]

#### `fn eq(&self, other: &&'b mut B) -> bool`
[src]

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

#### `fn ne(&self, other: &&'b mut B) -> bool`
[src]

This method tests for `!=`.

### `impl<'a, 'b, A, B> PartialEq<&'b mut B> for &'a A where
A: PartialEq<B> + ?Sized,
B: ?Sized,`
[src]

#### `fn eq(&self, other: &&'b mut B) -> bool`
[src]

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

#### `fn ne(&self, other: &&'b mut B) -> bool`
[src]

This method tests for `!=`.

### `impl<'a, T> LowerExp for &'a T where
T: LowerExp + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> LowerExp for &'a mut T where
T: LowerExp + ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, A> Ord for &'a A where
A: Ord + ?Sized,`
[src]

#### `fn cmp(&self, other: &&'a A) -> 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<'a, A> Ord for &'a mut A where
A: Ord + ?Sized,`
[src]

#### `fn cmp(&self, other: &&'a mut A) -> 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<'a, 'b, A, B> PartialOrd<&'b mut B> for &'a mut A where
A: PartialOrd<B> + ?Sized,
B: ?Sized,`
[src]

#### `fn partial_cmp(&self, other: &&'b mut B) -> Option<Ordering>`
[src]

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

#### `fn lt(&self, other: &&'b mut B) -> bool`
[src]

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

#### `fn le(&self, other: &&'b mut B) -> bool`
[src]

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

#### `fn ge(&self, other: &&'b mut B) -> bool`
[src]

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

#### `fn gt(&self, other: &&'b mut B) -> bool`
[src]

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

### `impl<'a, 'b, A, B> PartialOrd<&'b B> for &'a A where
A: PartialOrd<B> + ?Sized,
B: ?Sized,`
[src]

#### `fn partial_cmp(&self, other: &&'b B) -> Option<Ordering>`
[src]

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

#### `fn lt(&self, other: &&'b B) -> bool`
[src]

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

#### `fn le(&self, other: &&'b B) -> bool`
[src]

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

#### `fn ge(&self, other: &&'b B) -> bool`
[src]

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

#### `fn gt(&self, other: &&'b B) -> bool`
[src]

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

### `impl<'a, T, U> CoerceUnsized<*const U> for &'a T where
T: Unsize<U> + ?Sized,
U: ?Sized,`
[src]

### `impl<'a, 'b, T, U> CoerceUnsized<&'a U> for &'b T where
'b: 'a,
T: Unsize<U> + ?Sized,
U: ?Sized,`
[src]

### `impl<'a, T, U> CoerceUnsized<*mut U> for &'a mut T where
T: Unsize<U> + ?Sized,
U: ?Sized,`
[src]

### `impl<'a, T, U> CoerceUnsized<*const U> for &'a mut T where
T: Unsize<U> + ?Sized,
U: ?Sized,`
[src]

### `impl<'a, T, U> CoerceUnsized<&'a mut U> for &'a mut T where
T: Unsize<U> + ?Sized,
U: ?Sized,`
[src]

### `impl<'a, 'b, T, U> CoerceUnsized<&'a U> for &'b mut T where
'b: 'a,
T: Unsize<U> + ?Sized,
U: ?Sized,`
[src]

### `impl<'a, I> DoubleEndedIterator for &'a mut I where
I: DoubleEndedIterator + ?Sized,`
[src]

#### `fn next_back(&mut self) -> Option<<I as Iterator>::Item>`
[src]

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

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

🔬 This is a nightly-only experimental API. (`iter_rfind` #39480)

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

### `impl<'a, T, U> AsMut<U> for &'a mut T where
T: AsMut<U> + ?Sized,
U: ?Sized,`
[src]

#### `fn as_mut(&mut self) -> &mut U`
[src]

Performs the conversion.

### `impl<'a, A, F> Fn<A> for &'a F where
F: Fn<A> + ?Sized,`
[src]

#### `extern "rust-call" fn call(&self, args: A) -> <F as FnOnce<A>>::Output`
[src]

🔬 This is a nightly-only experimental API. (`fn_traits` #29625)

Performs the call operation.

### `impl<'a, T> Pointer for &'a T where
T: ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> Pointer for &'a mut T where
T: ?Sized,`
[src]

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

Formats the value using the given formatter.

### `impl<'a, T> Hash for &'a mut T where
T: Hash + ?Sized,`
[src]

#### `fn hash<H>(&self, state: &mut H) where
H: Hasher,`
[src]

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<'a, T> Hash for &'a T where
T: Hash + ?Sized,`
[src]

#### `fn hash<H>(&self, state: &mut H) where
H: Hasher,`
[src]

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<'a, R: Read + ?Sized> Read for &'a mut R`
[src]

#### `fn read(&mut self, buf: &mut [u8]) -> Result<usize>`
[src]

Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more

#### `unsafe fn initializer(&self) -> Initializer`
[src]

🔬 This is a nightly-only experimental API. (`read_initializer` #42788)

Determines if this `Read`er can work with buffers of uninitialized memory. Read more

#### `fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize>`
[src]

Read all bytes until EOF in this source, placing them into `buf`. Read more

#### `fn read_to_string(&mut self, buf: &mut String) -> Result<usize>`
[src]

Read all bytes until EOF in this source, placing them into `buf`. Read more

#### `fn read_exact(&mut self, buf: &mut [u8]) -> Result<()>`
[src]

Read the exact number of bytes required to fill `buf`. Read more

#### `fn by_ref(&mut self) -> &mut Self where
Self: Sized,`
[src]

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

#### `fn bytes(self) -> Bytes<Self> where
Self: Sized,`
[src]

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

#### `fn chars(self) -> Chars<Self> where
Self: Sized,`
[src]

🔬 This is a nightly-only experimental API. (`io` #27802)

the semantics of a partial read/write of where errors happen is currently unclear and may change

Transforms this `Read` instance to an [`Iterator`] over [`char`]s. Read more

#### `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

#### `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<'a, W: Write + ?Sized> Write for &'a mut W`
[src]

#### `fn write(&mut self, buf: &[u8]) -> Result<usize>`
[src]

Write a buffer into this object, returning how many bytes were written. Read more

#### `fn flush(&mut self) -> Result<()>`
[src]

Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more

#### `fn write_all(&mut self, buf: &[u8]) -> Result<()>`
[src]

Attempts to write an entire buffer into this write. Read more

#### `fn write_fmt(&mut self, fmt: Arguments) -> Result<()>`
[src]

Writes a formatted string into this writer, returning any error encountered. Read more

#### `fn by_ref(&mut self) -> &mut Self where
Self: Sized,`
[src]

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

### `impl<'a, S: Seek + ?Sized> Seek for &'a mut S`
[src]

#### `fn seek(&mut self, pos: SeekFrom) -> Result<u64>`
[src]

Seek to an offset, in bytes, in a stream. Read more

### `impl<'a, B: BufRead + ?Sized> BufRead for &'a mut B`
[src]

#### `fn fill_buf(&mut self) -> Result<&[u8]>`
[src]

Fills the internal buffer of this object, returning the buffer contents. Read more

#### `fn consume(&mut self, amt: usize)`
[src]

Tells this buffer that `amt` bytes have been consumed from the buffer, so they should no longer be returned in calls to `read`. Read more

#### `fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> Result<usize>`
[src]

Read all bytes into `buf` until the delimiter `byte` or EOF is reached. Read more

#### `fn read_line(&mut self, buf: &mut String) -> Result<usize>`
[src]

Read all bytes until a newline (the 0xA byte) is reached, and append them to the provided buffer. Read more

#### `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

#### `fn lines(self) -> Lines<Self> where
Self: Sized,`
[src]

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

### `impl<'a, T: ToSocketAddrs + ?Sized> ToSocketAddrs for &'a T`
[src]

#### `type Iter = T::Iter`

Returned iterator over socket addresses which this type may correspond to. Read more

#### `fn to_socket_addrs(&self) -> Result<T::Iter>`
[src]

Converts this object to an iterator of resolved `SocketAddr`s. Read more

### `impl<'a, T: ?Sized> !UnwindSafe for &'a mut T`
1.9.0
[src]

### `impl<'a, T: RefUnwindSafe + ?Sized> UnwindSafe for &'a T`
1.9.0
[src]

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