Primitive Type tuple

1.0.0 ·

Expand description

A finite heterogeneous sequence, (T, U, ..).

Let’s cover each of those in turn:

Tuples are finite. In other words, a tuple has a length. Here’s a tuple of length 3:

("hello", 5, 'c');

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‘Length’ is also sometimes called ‘arity’ here; each tuple of a different length is a different, distinct type.

Tuples are heterogeneous. This means that each element of the tuple can have a different type. In that tuple above, it has the type:

(&'static str, i32, char)

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Tuples are a sequence. This means that they can be accessed by position; this is called ‘tuple indexing’, and it looks like this:

let tuple = ("hello", 5, 'c');
assert_eq!(tuple.0, "hello");
assert_eq!(tuple.1, 5);
assert_eq!(tuple.2, 'c');

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The sequential nature of the tuple applies to its implementations of various traits. For example, in PartialOrd and Ord, the elements are compared sequentially until the first non-equal set is found.

For more about tuples, see the book.

Trait implementations

In this documentation the shorthand (T1, T2, ..., Tn) is used to represent tuples of varying length. When that is used, any trait bound expressed on T applies to each element of the tuple independently. Note that this is a convenience notation to avoid repetitive documentation, not valid Rust syntax.

Due to a temporary restriction in Rust’s type system, the following traits are only implemented on tuples of arity 12 or less. In the future, this may change:

• PartialEq
• Eq
• PartialOrd
• Ord
• Debug
• Default
• Hash

The following traits are implemented for tuples of any length. These traits have implementations that are automatically generated by the compiler, so are not limited by missing language features.

• Clone
• Copy
• Send
• Sync
• Unpin
• UnwindSafe
• RefUnwindSafe

Examples

Basic usage:

let tuple = ("hello", 5, 'c');
assert_eq!(tuple.0, "hello");

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Tuples are often used as a return type when you want to return more than one value:

fn calculate_point() -> (i32, i32) {
 // Don't do a calculation, that's not the point of the example
 (4, 5)
}
let point = calculate_point();
assert_eq!(point.0, 4);
assert_eq!(point.1, 5);
// Combining this with patterns can be nicer.
let (x, y) = calculate_point();
assert_eq!(x, 4);
assert_eq!(y, 5);

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Trait Implementations

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impl<T: Clone> Clone for (T1, T2, ..., Tn)

This trait is implemented on arbitrary-length tuples.

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fn clone(&self) -> Self

Returns a copy of the value. Read more

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

Performs copy-assignment from source. Read more

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impl<T> Debug for (T1, T2, ..., Tn) where
T: Debug + ?Sized,

This trait is implemented for tuples up to twelve items long.

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

Formats the value using the given formatter. Read more

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impl<T> Default for (T1, T2, ..., Tn) where
T: Default,

This trait is implemented for tuples up to twelve items long.

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fn default() -> (T,)

Returns the "default value" for a type. Read more

1.2.0 · source

impl<'a, K, V, A> Extend<(&'a K, &'a V)> for BTreeMap<K, V, A> where
K: Ord + Copy,
V: Copy,
A: Allocator + Clone,

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fn extend<I>(&mut self, iter: I) where
I: IntoIterator<Item = (&'a K, &'a V)>,

Extends a collection with the contents of an iterator. Read more

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fn extend_one(&mut self, (&'a K, &'a V))

🔬 This is a nightly-only experimental API. (extend_one #72631)

Extends a collection with exactly one element.

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fn extend_reserve(&mut self, additional: usize)

🔬 This is a nightly-only experimental API. (extend_one #72631)

Reserves capacity in a collection for the given number of additional elements. Read more

1.4.0 · source

impl<'a, K, V, S> Extend<(&'a K, &'a V)> for HashMap<K, V, S> where
K: Eq + Hash + Copy,
V: Copy,
S: BuildHasher,

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fn extend<T: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iter: T)

Extends a collection with the contents of an iterator. Read more

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fn extend_one(&mut self, (k, v): (&'a K, &'a V))

🔬 This is a nightly-only experimental API. (extend_one #72631)

Extends a collection with exactly one element.

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fn extend_reserve(&mut self, additional: usize)

🔬 This is a nightly-only experimental API. (extend_one #72631)

Reserves capacity in a collection for the given number of additional elements. Read more

1.56.0 · source

impl<A, B, ExtendA, ExtendB> Extend<(A, B)> for (ExtendA, ExtendB) where
ExtendA: Extend<A>,
ExtendB: Extend<B>,

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fn extend<T>(&mut self, into_iter: T) where
T: IntoIterator<Item = (A, B)>,

Allows to extend a tuple of collections that also implement Extend.

See also: Iterator::unzip

Examples

let mut tuple = (vec![0], vec![1]);
tuple.extend([(2, 3), (4, 5), (6, 7)]);
assert_eq!(tuple.0, [0, 2, 4, 6]);
assert_eq!(tuple.1, [1, 3, 5, 7]);
// also allows for arbitrarily nested tuples as elements
let mut nested_tuple = (vec![1], (vec![2], vec![3]));
nested_tuple.extend([(4, (5, 6)), (7, (8, 9))]);
let (a, (b, c)) = nested_tuple;
assert_eq!(a, [1, 4, 7]);
assert_eq!(b, [2, 5, 8]);
assert_eq!(c, [3, 6, 9]);

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fn extend_one(&mut self, item: (A, B))

🔬 This is a nightly-only experimental API. (extend_one #72631)

Extends a collection with exactly one element.

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fn extend_reserve(&mut self, additional: usize)

🔬 This is a nightly-only experimental API. (extend_one #72631)

Reserves capacity in a collection for the given number of additional elements. Read more

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impl<K, V, A> Extend<(K, V)> for BTreeMap<K, V, A> where
K: Ord,
A: Allocator + Clone,

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fn extend<T>(&mut self, iter: T) where
T: IntoIterator<Item = (K, V)>,

Extends a collection with the contents of an iterator. Read more

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fn extend_one(&mut self, (K, V))

🔬 This is a nightly-only experimental API. (extend_one #72631)

Extends a collection with exactly one element.

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fn extend_reserve(&mut self, additional: usize)

🔬 This is a nightly-only experimental API. (extend_one #72631)

Reserves capacity in a collection for the given number of additional elements. Read more

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impl<K, V, S> Extend<(K, V)> for HashMap<K, V, S> where
K: Eq + Hash,
S: BuildHasher,

Inserts all new key-values from the iterator and replaces values with existing keys with new values returned from the iterator.

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fn extend<T: IntoIterator<Item = (K, V)>>(&mut self, iter: T)

Extends a collection with the contents of an iterator. Read more

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fn extend_one(&mut self, (k, v): (K, V))

🔬 This is a nightly-only experimental API. (extend_one #72631)

Extends a collection with exactly one element.

source

fn extend_reserve(&mut self, additional: usize)

🔬 This is a nightly-only experimental API. (extend_one #72631)

Reserves capacity in a collection for the given number of additional elements. Read more

1.17.0 · source

impl<I: Into<IpAddr>> From<(I, u16)> for SocketAddr

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fn from(pieces: (I, u16)) -> SocketAddr

Converts a tuple struct (Into<IpAddr>, u16) into a SocketAddr.

This conversion creates a SocketAddr::V4 for an IpAddr::V4 and creates a SocketAddr::V6 for an IpAddr::V6.

u16 is treated as port of the newly created SocketAddr.

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impl<K, V> FromIterator<(K, V)> for BTreeMap<K, V, Global> where
K: Ord,

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fn from_iter<T>(iter: T) -> BTreeMap<K, V, Global> where
T: IntoIterator<Item = (K, V)>,

Creates a value from an iterator. Read more

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impl<K, V, S> FromIterator<(K, V)> for HashMap<K, V, S> where
K: Eq + Hash,
S: BuildHasher + Default,

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fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> HashMap<K, V, S>

Creates a value from an iterator. Read more

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impl<T> Hash for (T1, T2, ..., Tn) where
T: Hash + ?Sized,

This trait is implemented for tuples up to twelve items long.

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

Feeds this value into the given Hasher. Read more

1.3.0 · source

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

Feeds a slice of this type into the given Hasher. Read more

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impl<T> Ord for (T1, T2, ..., Tn) where
T: Ord + ?Sized,

This trait is implemented for tuples up to twelve items long.

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fn cmp(&self, other: &(T,)) -> Ordering

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

1.21.0 · source

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

Compares and returns the maximum of two values. Read more

1.21.0 · source

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

Compares and returns the minimum of two values. Read more

1.50.0 · source

fn clamp(self, min: Self, max: Self) -> Self where
Self: PartialOrd<Self>,

Restrict a value to a certain interval. Read more

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impl<T> PartialEq<(T,)> for (T1, T2, ..., Tn) where
T: PartialEq<T> + ?Sized,

This trait is implemented for tuples up to twelve items long.

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fn eq(&self, other: &(T,)) -> bool

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

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fn ne(&self, other: &(T,)) -> bool

This method tests for !=.

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impl<T> PartialOrd<(T,)> for (T1, T2, ..., Tn) where
T: PartialOrd<T> + PartialEq<T> + ?Sized,

This trait is implemented for tuples up to twelve items long.

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fn partial_cmp(&self, other: &(T,)) -> Option<Ordering>

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

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fn lt(&self, other: &(T,)) -> bool

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

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fn le(&self, other: &(T,)) -> bool

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

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fn ge(&self, other: &(T,)) -> bool

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

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fn gt(&self, other: &(T,)) -> bool

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

1.28.0 · source

impl<'a, T> RangeBounds<T> for (Bound<&'a T>, Bound<&'a T>) where
T: 'a + ?Sized,

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fn start_bound(&self) -> Bound<&T>

Start index bound. Read more

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fn end_bound(&self) -> Bound<&T>

End index bound. Read more

1.35.0 · source

fn contains<U>(&self, item: &U) -> bool where
T: PartialOrd<U>,
U: PartialOrd<T> + ?Sized,

Returns true if item is contained in the range. Read more

1.28.0 · source

impl<T> RangeBounds<T> for (Bound<T>, Bound<T>)

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fn start_bound(&self) -> Bound<&T>

Start index bound. Read more

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fn end_bound(&self) -> Bound<&T>

End index bound. Read more

1.35.0 · source

fn contains<U>(&self, item: &U) -> bool where
T: PartialOrd<U>,
U: PartialOrd<T> + ?Sized,

Returns true if item is contained in the range. Read more

1.53.0 · source

impl<T> SliceIndex<[T]> for (Bound<usize>, Bound<usize>)

type Output = [T]

The output type returned by methods.

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fn get(
self,
slice: &[T]
) -> Option<&<(Bound<usize>, Bound<usize>) as SliceIndex<[T]>>::Output>

🔬 This is a nightly-only experimental API. (slice_index_methods)

Returns a shared reference to the output at this location, if in bounds. Read more

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fn get_mut(
self,
slice: &mut [T]
) -> Option<&mut <(Bound<usize>, Bound<usize>) as SliceIndex<[T]>>::Output>

🔬 This is a nightly-only experimental API. (slice_index_methods)

Returns a mutable reference to the output at this location, if in bounds. Read more

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unsafe fn get_unchecked(
self,
slice: *const [T]
) -> *const <(Bound<usize>, Bound<usize>) as SliceIndex<[T]>>::Output

🔬 This is a nightly-only experimental API. (slice_index_methods)

Returns a shared reference to the output at this location, without performing any bounds checking. Calling this method with an out-of-bounds index or a dangling slice pointer is undefined behavior even if the resulting reference is not used. Read more

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unsafe fn get_unchecked_mut(
self,
slice: *mut [T]
) -> *mut <(Bound<usize>, Bound<usize>) as SliceIndex<[T]>>::Output

🔬 This is a nightly-only experimental API. (slice_index_methods)

Returns a mutable reference to the output at this location, without performing any bounds checking. Calling this method with an out-of-bounds index or a dangling slice pointer is undefined behavior even if the resulting reference is not used. Read more

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fn index(
self,
slice: &[T]
) -> &<(Bound<usize>, Bound<usize>) as SliceIndex<[T]>>::Output

🔬 This is a nightly-only experimental API. (slice_index_methods)

Returns a shared reference to the output at this location, panicking if out of bounds. Read more

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fn index_mut(
self,
slice: &mut [T]
) -> &mut <(Bound<usize>, Bound<usize>) as SliceIndex<[T]>>::Output

🔬 This is a nightly-only experimental API. (slice_index_methods)

Returns a mutable reference to the output at this location, panicking if out of bounds. Read more

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impl ToSocketAddrs for (&str, u16)

type Iter = IntoIter<SocketAddr, Global>

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

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fn to_socket_addrs(&self) -> Result<IntoIter<SocketAddr>>

Converts this object to an iterator of resolved SocketAddrs. Read more

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impl ToSocketAddrs for (IpAddr, u16)

type Iter = IntoIter<SocketAddr>

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

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fn to_socket_addrs(&self) -> Result<IntoIter<SocketAddr>>

Converts this object to an iterator of resolved SocketAddrs. Read more

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impl ToSocketAddrs for (Ipv4Addr, u16)

type Iter = IntoIter<SocketAddr>

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

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fn to_socket_addrs(&self) -> Result<IntoIter<SocketAddr>>

Converts this object to an iterator of resolved SocketAddrs. Read more

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impl ToSocketAddrs for (Ipv6Addr, u16)

type Iter = IntoIter<SocketAddr>

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

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fn to_socket_addrs(&self) -> Result<IntoIter<SocketAddr>>

Converts this object to an iterator of resolved SocketAddrs. Read more

1.46.0 · source

impl ToSocketAddrs for (String, u16)

type Iter = IntoIter<SocketAddr, Global>

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

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fn to_socket_addrs(&self) -> Result<IntoIter<SocketAddr>>

Converts this object to an iterator of resolved SocketAddrs. Read more

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impl<T: Copy> Copy for (T1, T2, ..., Tn)

This trait is implemented on arbitrary-length tuples.

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impl<T> Eq for (T1, T2, ..., Tn) where
T: Eq + ?Sized,

This trait is implemented for tuples up to twelve items long.