# 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, 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, T, U> AsMut<U> for &'a mut T where T: AsMut<U> + ?Sized, U: ?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 as_mut(&mut self) -> &mut U`

[src]

Performs the conversion.

###

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

1.26.0
[src]

###

`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> Generator for &'a mut T where T: Generator + ?Sized,`

[src]

#### `type Yield = <T as Generator>::Yield`

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

The type of value this generator yields. Read more

#### `type Return = <T as Generator>::Return`

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

The type of value this generator returns. Read more

####

`unsafe fn resume( &mut self ) -> GeneratorState<<&'a mut T as Generator>::Yield, <&'a mut T as Generator>::Return>`

[src]

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

Resumes the execution of this generator. 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> BorrowMut<T> for &'a mut 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<'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. Read more

###

`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. Read more

###

`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> Copy for &'a T where T: ?Sized,`

[src]

###

`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

####
ⓘImportant traits for StepBy<I>

### Important traits for StepBy<I>

`impl<I> Iterator for StepBy<I> where
I: Iterator, type Item = <I as Iterator>::Item;`

`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

####
ⓘImportant traits for Chain<A, B>

### Important traits for Chain<A, B>

`impl<A, B> Iterator for Chain<A, B> where
A: Iterator,
B: Iterator<Item = <A as Iterator>::Item>, type Item = <A as Iterator>::Item;`

`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>

### Important traits for Zip<A, B>

`impl<A, B> Iterator for Zip<A, B> where
A: Iterator,
B: Iterator, type Item = (<A as Iterator>::Item, <B as Iterator>::Item);`

`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>

### Important traits for Map<I, F>

`impl<B, I, F> Iterator for Map<I, F> where
F: FnMut(<I as Iterator>::Item) -> B,
I: Iterator, type Item = B;`

`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>

### Important traits for Filter<I, P>

`impl<I, P> Iterator for Filter<I, P> where
I: Iterator,
P: FnMut(&<I as Iterator>::Item) -> bool, type Item = <I as Iterator>::Item;`

`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>

### Important traits for FilterMap<I, F>

`impl<B, I, F> Iterator for FilterMap<I, F> where
F: FnMut(<I as Iterator>::Item) -> Option<B>,
I: Iterator, type Item = B;`

`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>

### Important traits for Enumerate<I>

`impl<I> Iterator for Enumerate<I> where
I: Iterator, type Item = (usize, <I as Iterator>::Item);`

`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>

### Important traits for Peekable<I>

`impl<I> Iterator for Peekable<I> where
I: Iterator, type Item = <I as Iterator>::Item;`

`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>

### Important traits for SkipWhile<I, P>

`impl<I, P> Iterator for SkipWhile<I, P> where
I: Iterator,
P: FnMut(&<I as Iterator>::Item) -> bool, type Item = <I as Iterator>::Item;`

`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>

### Important traits for TakeWhile<I, P>

`impl<I, P> Iterator for TakeWhile<I, P> where
I: Iterator,
P: FnMut(&<I as Iterator>::Item) -> bool, type Item = <I as Iterator>::Item;`

`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>

### Important traits for Skip<I>

`impl<I> Iterator for Skip<I> where
I: Iterator, type Item = <I as Iterator>::Item;`

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

[src]

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

####
ⓘImportant traits for Take<I>

### Important traits for Take<I>

`impl<I> Iterator for Take<I> where
I: Iterator, type Item = <I as Iterator>::Item;`

`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>

### Important traits for Scan<I, St, F>

`impl<B, I, St, F> Iterator for Scan<I, St, F> where
F: FnMut(&mut St, <I as Iterator>::Item) -> Option<B>,
I: Iterator, type Item = B;`

`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>

### Important traits for FlatMap<I, U, F>

`impl<I, U, F> Iterator for FlatMap<I, U, F> where
F: FnMut(<I as Iterator>::Item) -> U,
I: Iterator,
U: IntoIterator, type Item = <U as IntoIterator>::Item;`

`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>

### Important traits for Flatten<I>

`impl<I, U> Iterator for Flatten<I> where
I: Iterator,
U: Iterator,
<I as Iterator>::Item: IntoIterator,
<<I as Iterator>::Item as IntoIterator>::IntoIter == U,
<<I as Iterator>::Item as IntoIterator>::Item == <U as Iterator>::Item, type Item = <U as Iterator>::Item;`

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

[src]

🔬 This is a nightly-only experimental API. (`iterator_flatten` #48213)

Creates an iterator that flattens nested structure. Read more

####
ⓘImportant traits for Fuse<I>

### Important traits for Fuse<I>

`impl<I> Iterator for Fuse<I> where
I: Iterator, type Item = <I as Iterator>::Item;impl<I> Iterator for Fuse<I> where
I: FusedIterator,`

`fn fuse(self) -> Fuse<Self>`

[src]

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

####
ⓘImportant traits for Inspect<I, F>

### Important traits for Inspect<I, F>

`impl<I, F> Iterator for Inspect<I, F> where
F: FnMut(&<I as Iterator>::Item),
I: Iterator, type Item = <I as Iterator>::Item;`

`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 &'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 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 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>,`

[src]

🔬 This is a nightly-only experimental API. (`iterator_find_map` #49602)

unstable new API

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>

### Important traits for Rev<I>

`impl<I> Iterator for Rev<I> where
I: DoubleEndedIterator, type Item = <I as Iterator>::Item;`

`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 Cloned<I>

### Important traits for Cloned<I>

`impl<'a, I, T> Iterator for Cloned<I> where
I: Iterator<Item = &'a T>,
T: 'a + Clone, type Item = T;`

`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>

### Important traits for Cycle<I>

`impl<I> Iterator for Cycle<I> where
I: Clone + Iterator, type Item = <I as Iterator>::Item;`

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

####
ⓘ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 as_ref(&self) -> &U`

[src]

Performs the conversion.

###

`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, 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, T> Clone for &'a 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 clone(&self) -> &'a T`

[src]

Returns a copy of the value. Read more

####

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

[src]

Performs copy-assignment from `source`. 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, '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, 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> Borrow<T> for &'a 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<'a, T> Borrow<T> for &'a mut 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<'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 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<'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, 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, 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, H> Hasher for &'a mut H where H: Hasher + ?Sized,`

1.22.0
[src]

####

`fn finish(&self) -> u64`

[src]

Returns the hash value for the values written so far. Read more

####

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

[src]

Writes some data into this `Hasher`. Read more

####

`fn write_u8(&mut self, i: u8)`

[src]

Writes a single `u8` into this hasher.

####

`fn write_u16(&mut self, i: u16)`

[src]

Writes a single `u16` into this hasher.

####

`fn write_u32(&mut self, i: u32)`

[src]

Writes a single `u32` into this hasher.

####

`fn write_u64(&mut self, i: u64)`

[src]

Writes a single `u64` into this hasher.

####

`fn write_u128(&mut self, i: u128)`

[src]

Writes a single `u128` into this hasher.

####

`fn write_usize(&mut self, i: usize)`

[src]

Writes a single `usize` into this hasher.

####

`fn write_i8(&mut self, i: i8)`

[src]

Writes a single `i8` into this hasher.

####

`fn write_i16(&mut self, i: i16)`

[src]

Writes a single `i16` into this hasher.

####

`fn write_i32(&mut self, i: i32)`

[src]

Writes a single `i32` into this hasher.

####

`fn write_i64(&mut self, i: i64)`

[src]

Writes a single `i64` into this hasher.

####

`fn write_i128(&mut self, i: i128)`

[src]

Writes a single `i128` into this hasher.

####

`fn write_isize(&mut self, i: isize)`

[src]

Writes a single `isize` into this hasher.

###

`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, 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, 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, T> DerefMut for &'a mut 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 deref_mut(&mut self) -> &mut T`

[src]

Mutably dereferences the value.

###

`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, '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 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, T, U> CoerceUnsized<&'a mut U> for &'a mut T where 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, 'b, T, U> CoerceUnsized<&'a U> for &'b mut T where 'b: 'a, 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<*const U> for &'a T where T: Unsize<U> + ?Sized, U: ?Sized,`

[src]

###

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

[src]

#### `type Target = T`

The resulting type after dereferencing.

####
ⓘ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 deref(&self) -> &T`

[src]

Dereferences the value.

###

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

[src]

#### `type Target = T`

The resulting type after dereferencing.

####
ⓘ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 deref(&self) -> &T`

[src]

Dereferences the value.

###

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

[src]

###

`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, 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> 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, 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> 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> 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, 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, appending them to `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

####
ⓘ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 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>

### Important traits for Bytes<R>

`impl<R: Read> Iterator for Bytes<R> type Item = Result<u8>;`

`fn bytes(self) -> Bytes<Self> where Self: Sized,`

[src]

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

####
ⓘImportant traits for Chars<R>

### Important traits for Chars<R>

`impl<R: Read> Iterator for Chars<R> type Item = Result<char, CharsError>;`

`fn chars(self) -> Chars<Self> where Self: Sized,`

[src]

Deprecated since 1.27.0

: Use str::from_utf8 instead: https://doc.rust-lang.org/nightly/std/str/struct.Utf8Error.html#examples

🔬 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

####
ⓘImportant traits for Chain<T, U>

### Important traits for Chain<T, U>

`impl<T: Read, U: Read> Read 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>

### Important traits for Take<T>

`impl<T: Read> Read 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<'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

####
ⓘ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 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

####
ⓘImportant traits for Split<B>

### Important traits for Split<B>

`impl<B: BufRead> Iterator for Split<B> type Item = Result<Vec<u8>>;`

`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>

### Important traits for Lines<B>

`impl<B: BufRead> Iterator for Lines<B> type Item = Result<String>;`

`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]

# Help

## Keyboard Shortcuts

`?`
  Show this help dialog
`S`
  Focus the search field
`↑`
  Move up in search results
`↓`
  Move down in search results
`↹`
  Switch tab
`⏎`
  Go to active search result
`+`
  Expand all sections
`-`
  Collapse all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize` or `* -> vec`)

Search multiple things at once by splitting your query with comma (e.g. `str,u8` or `String,struct:Vec,test`)