# 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:

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.

## 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: ?Sized + Debug,

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

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

Formats the value using the given formatter. Read more
const: unstable · source§

### impl<T: Default> Default for (T₁, T₂, …, Tₙ)

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

const: unstable · source§

#### fn default() -> (T,)

Returns the “default value” for a type. 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: IntoIterator<Item = (A, B)>>(&mut self, into_iter: T)

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
1.17.0 · source§

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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`.

const: unstable · source§

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

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

const: unstable · source§

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

Feeds this value into the given `Hasher`. Read more
const: unstable · source§

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

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

const: unstable · source§

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

This method returns an `Ordering` between `self` and `other`. Read more
const: unstable · source§

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

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

const: unstable · source§

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

This method tests for `self` and `other` values to be equal, and is used by `==`.
const: unstable · source§

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

This method tests for `!=`. The default implementation is almost always sufficient, and should not be overridden without very good reason.
const: unstable · source§

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

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

const: unstable · source§

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

This method returns an ordering between `self` and `other` values if one exists. Read more
const: unstable · source§

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

This method tests less than (for `self` and `other`) and is used by the `<` operator. Read more
const: unstable · source§

#### 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
const: unstable · source§

#### 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
const: unstable · source§

#### 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 (const: unstable) · source§

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

const: unstable · source§

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

const: unstable · source§

1.35.0 · source§

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

Returns `true` if `item` is contained in the range. Read more
1.28.0 (const: unstable) · source§

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

const: unstable · source§

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

const: unstable · source§

1.35.0 · source§

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

Returns `true` if `item` is contained in the range. Read more
1.53.0 · source§

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

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#### type Output = [T]

The output type returned by methods.
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#### fn get(self, slice: &[T]) -> Option<&Self::Output>

🔬This is a nightly-only experimental API. (`slice_index_methods`)
Returns a shared reference to the output at this location, if in bounds.
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#### fn get_mut(self, slice: &mut [T]) -> Option<&mut Self::Output>

🔬This is a nightly-only experimental API. (`slice_index_methods`)
Returns a mutable reference to the output at this location, if in bounds.
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#### unsafe fn get_unchecked(self, slice: *const [T]) -> *const Self::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.
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#### unsafe fn get_unchecked_mut(self, slice: *mut [T]) -> *mut Self::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.
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#### fn index(self, slice: &[T]) -> &Self::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.
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#### fn index_mut(self, slice: &mut [T]) -> &mut Self::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.
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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: ?Sized + Eq,

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

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## Blanket Implementations§

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### impl<T> Any for Twhere T: 'static + ?Sized,

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#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
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### impl<T> Borrow<T> for Twhere T: ?Sized,

const: unstable · source§

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

Immutably borrows from an owned value. Read more
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### impl<T> BorrowMut<T> for Twhere T: ?Sized,

const: unstable · source§

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

Mutably borrows from an owned value. Read more
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### impl<T> From<T> for T

const: unstable · source§

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

Returns the argument unchanged.

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### impl<T, U> Into<U> for Twhere U: From<T>,

const: unstable · source§

#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

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### impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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#### type Error = Infallible

The type returned in the event of a conversion error.
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#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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### impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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

The type returned in the event of a conversion error.
const: unstable · source§

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

Performs the conversion.