Primitive Type reference

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

impl<'a, 'b, T, U> CoerceUnsized<&'a U> for &'b T where
    'b: 'a,
    T: Unsize<U> + ?Sized,
    U: ?Sized, 

impl<'a, T, U> CoerceUnsized<&'a mut U> for &'a mut T where
    T: Unsize<U> + ?Sized,
    U: ?Sized, 

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

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

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

impl<'a, T> UpperHex for &'a T where
    T: UpperHex + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> UpperHex for &'a mut T where
    T: UpperHex + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> Octal for &'a mut T where
    T: Octal + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> Octal for &'a T where
    T: Octal + ?Sized, 

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

Formats the value using the given formatter.

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

fn as_ref(&self) -> &U

Performs the conversion.

impl<'a, T, U> AsRef<U> for &'a T where
    T: AsRef<U> + ?Sized,
    U: ?Sized, 

fn as_ref(&self) -> &U

Performs the conversion.

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

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

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

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<'a, 'b, A, B> PartialOrd<&'b mut B> for &'a mut A where
    A: PartialOrd<B> + ?Sized,
    B: ?Sized, 

fn partial_cmp(&self, other: &&'b mut B) -> Option<Ordering>

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

fn lt(&self, other: &&'b mut B) -> bool

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

fn le(&self, other: &&'b mut B) -> bool

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

fn ge(&self, other: &&'b mut B) -> bool

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

fn gt(&self, other: &&'b mut B) -> bool

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

impl<'a, 'b, A, B> PartialOrd<&'b B> for &'a A where
    A: PartialOrd<B> + ?Sized,
    B: ?Sized, 

fn partial_cmp(&self, other: &&'b B) -> Option<Ordering>

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

fn lt(&self, other: &&'b B) -> bool

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

fn le(&self, other: &&'b B) -> bool

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

fn ge(&self, other: &&'b B) -> bool

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

fn gt(&self, other: &&'b B) -> bool

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

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

fn borrow(&self) -> &T

Immutably borrows from an owned value.

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

fn borrow(&self) -> &T

Immutably borrows from an owned value.

impl<'a, A> Eq for &'a A where
    A: Eq + ?Sized, 

impl<'a, A> Eq for &'a mut A where
    A: Eq + ?Sized, 

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

impl<'a, A, F> FnMut<A> for &'a F where
    F: Fn<A> + ?Sized, 

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

🔬 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, 

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

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

Performs the call operation.

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

fn len(&self) -> usize

Returns the exact number of times the iterator will iterate.

fn is_empty(&self) -> bool

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

Returns whether the iterator is empty.

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

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

Formats the value using the given formatter.

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

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

Formats the value using the given formatter.

impl<'a, T> Binary for &'a T where
    T: Binary + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> Binary for &'a mut T where
    T: Binary + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> Debug for &'a T where
    T: Debug + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> Debug for &'a mut T where
    T: Debug + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> Send for &'a mut T where
    T: Send + ?Sized, 

impl<'a, T> Send for &'a T where
    T: Sync + ?Sized, 

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

type Item = <I as Iterator>::Item

The type of the elements being iterated over.

fn next(&mut self) -> Option<<I as Iterator>::Item>

Advances the iterator and returns the next value.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the iterator.

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

Returns the nth element of the iterator.

fn count(self) -> usize

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

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

Consumes the iterator, returning the last element.

fn step_by(self, step: usize) -> StepBy<Self>

🔬 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.

fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator<Item = Self::Item>, 

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

fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator, 

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

fn map<B, F>(self, f: F) -> Map<Self, F> where
    F: FnMut(Self::Item) -> B, 

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

fn for_each<F>(self, f: F) where
    F: FnMut(Self::Item) -> (), 

Calls a closure on each element of an iterator.

fn filter<P>(self, predicate: P) -> Filter<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

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

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where
    F: FnMut(Self::Item) -> Option<B>, 

Creates an iterator that both filters and maps.

fn enumerate(self) -> Enumerate<Self>

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

fn peekable(self) -> Peekable<Self>

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

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

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

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator that yields elements based on a predicate.

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

Creates an iterator that skips the first n elements.

fn take(self, n: usize) -> Take<Self>

Creates an iterator that yields its first n elements.

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where
    F: FnMut(&mut St, Self::Item) -> Option<B>, 

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

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
    F: FnMut(Self::Item) -> U,
    U: IntoIterator, 

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

fn fuse(self) -> Fuse<Self>

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

fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnMut(&Self::Item) -> (), 

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

fn by_ref(&mut self) -> &mut Self

Borrows an iterator, rather than consuming it.

fn collect<B>(self) -> B where
    B: FromIterator<Self::Item>, 

Transforms an iterator into a collection.

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

Consumes an iterator, creating two collections from it.

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

An iterator adaptor that applies a function, producing a single, final value.

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

Tests if every element of the iterator matches a predicate.

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

Tests if any element of the iterator matches a predicate.

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

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

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

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

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

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

fn max(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the maximum element of an iterator.

fn min(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the minimum element of an iterator.

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

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

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

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

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

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

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

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

fn rev(self) -> Rev<Self> where
    Self: DoubleEndedIterator, 

Reverses an iterator's direction.

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

Converts an iterator of pairs into a pair of containers.

fn cloned<'a, T>(self) -> Cloned<Self> where
    Self: Iterator<Item = &'a T>,
    T: 'a + Clone, 

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

fn cycle(self) -> Cycle<Self> where
    Self: Clone, 

Repeats an iterator endlessly.

fn sum<S>(self) -> S where
    S: Sum<Self::Item>, 

Sums the elements of an iterator.

fn product<P>(self) -> P where
    P: Product<Self::Item>, 

Iterates over the entire iterator, multiplying all the elements

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

impl<'a, T, U> AsMut<U> for &'a mut T where
    T: AsMut<U> + ?Sized,
    U: ?Sized, 

fn as_mut(&mut self) -> &mut U

Performs the conversion.

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

fn next_back(&mut self) -> Option<<I as Iterator>::Item>

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

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

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

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

impl<'a, W> Write for &'a mut W where
    W: Write + ?Sized, 

fn write_str(&mut self, s: &str) -> Result<(), Error>

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

fn write_char(&mut self, c: char) -> Result<(), Error>

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

fn write_fmt(&mut self, args: Arguments) -> Result<(), Error>

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

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

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

Mutably borrows from an owned value.

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

impl<'a, A, F> FnOnce<A> for &'a F where
    F: Fn<A> + ?Sized, 

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

🔬 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, 

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

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

Performs the call operation.

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

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

Mutably dereferences the value.

impl<'a, A> Ord for &'a A where
    A: Ord + ?Sized, 

fn cmp(&self, other: &&'a A) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl<'a, A> Ord for &'a mut A where
    A: Ord + ?Sized, 

fn cmp(&self, other: &&'a mut A) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl<'a, T> LowerExp for &'a T where
    T: LowerExp + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> LowerExp for &'a mut T where
    T: LowerExp + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, 'b, A, B> PartialEq<&'b mut B> for &'a mut A where
    A: PartialEq<B> + ?Sized,
    B: ?Sized, 

fn eq(&self, other: &&'b mut B) -> bool

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

fn ne(&self, other: &&'b mut B) -> bool

This method tests for !=.

impl<'a, 'b, A, B> PartialEq<&'b mut B> for &'a A where
    A: PartialEq<B> + ?Sized,
    B: ?Sized, 

fn eq(&self, other: &&'b mut B) -> bool

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

fn ne(&self, other: &&'b mut B) -> bool

This method tests for !=.

impl<'a, 'b, A, B> PartialEq<&'b B> for &'a mut A where
    A: PartialEq<B> + ?Sized,
    B: ?Sized, 

fn eq(&self, other: &&'b B) -> bool

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

fn ne(&self, other: &&'b B) -> bool

This method tests for !=.

impl<'a, 'b, A, B> PartialEq<&'b B> for &'a A where
    A: PartialEq<B> + ?Sized,
    B: ?Sized, 

fn eq(&self, other: &&'b B) -> bool

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

fn ne(&self, other: &&'b B) -> bool

This method tests for !=.

impl<'a, T> LowerHex for &'a mut T where
    T: LowerHex + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> LowerHex for &'a T where
    T: LowerHex + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> Display for &'a T where
    T: Display + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> Display for &'a mut T where
    T: Display + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> Hash for &'a T where
    T: Hash + ?Sized, 

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

Feeds this value into the given [Hasher].

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

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

impl<'a, T> Hash for &'a mut T where
    T: Hash + ?Sized, 

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

Feeds this value into the given [Hasher].

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

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

impl<'a, A, F> Fn<A> for &'a F where
    F: Fn<A> + ?Sized, 

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

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

Performs the call operation.

impl<'a, T> UpperExp for &'a mut T where
    T: UpperExp + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, T> UpperExp for &'a T where
    T: UpperExp + ?Sized, 

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

Formats the value using the given formatter.

impl<'a, R: Read + ?Sized> Read for &'a mut R

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

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

unsafe fn initializer(&self) -> Initializer

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

Determines if this Reader can work with buffers of uninitialized memory.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize>

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

fn read_to_string(&mut self, buf: &mut String) -> Result<usize>

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

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

Read the exact number of bytes required to fill buf.

fn by_ref(&mut self) -> &mut Self where
    Self: Sized, 

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

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

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

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

🔬 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.

fn chain<R: Read>(self, next: R) -> Chain<Self, R> where
    Self: Sized, 

Creates an adaptor which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self> where
    Self: Sized, 

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

impl<'a, W: Write + ?Sized> Write for &'a mut W

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

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

fn flush(&mut self) -> Result<()>

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

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

Attempts to write an entire buffer into this write.

fn write_fmt(&mut self, fmt: Arguments) -> Result<()>

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

fn by_ref(&mut self) -> &mut Self where
    Self: Sized, 

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

impl<'a, S: Seek + ?Sized> Seek for &'a mut S

fn seek(&mut self, pos: SeekFrom) -> Result<u64>

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

impl<'a, B: BufRead + ?Sized> BufRead for &'a mut B

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

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

fn consume(&mut self, amt: usize)

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

fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> Result<usize>

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

fn read_line(&mut self, buf: &mut String) -> Result<usize>

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

fn split(self, byte: u8) -> Split<Self> where
    Self: Sized, 

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

fn lines(self) -> Lines<Self> where
    Self: Sized, 

Returns an iterator over the lines of this reader.

impl<'a, T: ToSocketAddrs + ?Sized> ToSocketAddrs for &'a T

type Iter = T::Iter

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

fn to_socket_addrs(&self) -> Result<T::Iter>

Converts this object to an iterator of resolved SocketAddrs.

impl<'a, T: ?Sized> !UnwindSafe for &'a mut T

impl<'a, T: RefUnwindSafe + ?Sized> UnwindSafe for &'a T