# 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');

‘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)

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');

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`
- `From<[T; N]>`

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");

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);

Homogeneous tuples can be created from arrays of appropriate length:

    let array: [u32; 3] = [1, 2, 3];
    let tuple: (u32, u32, u32) = array.into();

## Trait Implementations§

1.0.0 · Source§

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

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

Source§

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

Formats the value using the given formatter. Read more
1.0.0 · Source§

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

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

Source§

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

Returns the “default value” for a type. Read more
1.56.0 · Source§

### impl<A, EA> Extend<(A₁, A₂, …, Aₙ)> for (EA₁, EA₂, …, EAₙ)
where EA: Extend<A>,

This trait is implemented for tuples up to twelve items long. The `impl`s for 1- and 3- through 12-ary tuples were stabilized after 2-tuples, in 1.85.0.

Source§

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

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

See also: `Iterator::unzip`

##### §Examples

    // Example given for a 2-tuple, but 1- through 12-tuples are supported
    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]);

Source§

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

🔬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
1.71.0 · Source§

### impl<T> From<[T; N]> for (T₁, T₂, …, Tₙ)

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

Source§

#### fn from(array: [T; 1]) -> Self

Converts to this type from the input type.
1.17.0 (const: unstable) · Source§

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

Source§

#### 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`.

1.71.0 · Source§

### impl<T> From<(T₁, T₂, …, Tₙ)> for [T; N]

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

Source§

#### fn from(tuple: (T,)) -> Self

Converts to this type from the input type.
1.79.0 · Source§

### impl<A, EA> FromIterator<(EA₁, EA₂, …, EAₙ)> for (A₁, A₂, …, Aₙ)
where A: Default + Extend<EA>,

This implementation turns an iterator of tuples into a tuple of types which implement `Default` and `Extend`.

This is similar to `Iterator::unzip`, but is also composable with other `FromIterator` implementations:

    let string = "1,2,123,4";

    // Example given for a 2-tuple, but 1- through 12-tuples are supported
    let (numbers, lengths): (Vec<_>, Vec<_>) = string
        .split(',')
        .map(|s| s.parse().map(|n: u32| (n, s.len())))
        .collect::<Result<_, _>>()?;

    assert_eq!(numbers, [1, 2, 123, 4]);
    assert_eq!(lengths, [1, 1, 3, 1]);

This trait is implemented for tuples up to twelve items long. The `impl`s for 1- and 3- through 12-ary tuples were stabilized after 2-tuples, in 1.85.0.

Source§

#### fn from_iter<Iter: IntoIterator<Item = (EA,)>>(iter: Iter) -> Self

Creates a value from an iterator. Read more
1.0.0 · Source§

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

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

Source§

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

Feeds this value into the given `Hasher`. Read more
1.3.0 · Source§

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

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

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

Source§

#### fn into_bounds(self) -> (Bound<T>, Bound<T>)

🔬This is a nightly-only experimental API. (`range_into_bounds` #136903)
Convert this range into the start and end bounds. Returns `(start_bound, end_bound)`. Read more
Source§

#### fn intersect<R>(self, other: R) -> (Bound<T>, Bound<T>)
where Self: Sized, T: Ord, R: Sized + IntoBounds<T>,

🔬This is a nightly-only experimental API. (`range_into_bounds` #136903)
Compute the intersection of `self` and `other`. Read more
1.0.0 · Source§

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

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

Source§

#### 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
where Self: Sized,

Compares and returns the maximum of two values. Read more
1.21.0 · Source§

#### fn min(self, other: Self) -> Self
where Self: Sized,

Compares and returns the minimum of two values. Read more
1.50.0 · Source§

#### fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized,

Restrict a value to a certain interval. Read more
1.0.0 · Source§

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

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

Source§

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

Tests for `self` and `other` values to be equal, and is used by `==`.
Source§

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

Tests for `!=`. The default implementation is almost always sufficient, and should not be overridden without very good reason.
1.0.0 · Source§

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

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

Source§

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

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

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

Tests less than (for `self` and `other`) and is used by the `<` operator. Read more
Source§

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

Tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more
Source§

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

Tests greater than or equal to (for `self` and `other`) and is used by the `>=` operator. Read more
Source§

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

Tests greater than (for `self` and `other`) and is used by the `>` operator. Read more
1.28.0 · Source§

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

Source§

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

Start index bound. Read more
Source§

#### 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: ?Sized + PartialOrd<T>,

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

#### fn is_empty(&self) -> bool
where T: PartialOrd,

🔬This is a nightly-only experimental API. (`range_bounds_is_empty` #137300)
Returns `true` if the range contains no items. One-sided ranges (`RangeFrom`, etc) always return `false`. Read more
1.28.0 · Source§

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

Source§

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

Start index bound. Read more
Source§

#### 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: ?Sized + PartialOrd<T>,

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

#### fn is_empty(&self) -> bool
where T: PartialOrd,

🔬This is a nightly-only experimental API. (`range_bounds_is_empty` #137300)
Returns `true` if the range contains no items. One-sided ranges (`RangeFrom`, etc) always return `false`. Read more
1.53.0 · Source§

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

Source§

#### type Output = [T]

The output type returned by methods.
Source§

#### 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.
Source§

#### 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.
Source§

#### unsafe fn get_unchecked(self, slice: *const [T]) -> *const Self::Output

🔬This is a nightly-only experimental API. (`slice_index_methods`)
Returns a pointer to the output at this location, without performing any bounds checking. Read more
Source§

#### 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 pointer to the output at this location, without performing any bounds checking. Read more
Source§

#### 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.
Source§

#### 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.
Source§

### impl SliceIndex<ByteStr> for (Bound<usize>, Bound<usize>)

Source§

#### type Output = ByteStr

The output type returned by methods.
Source§

#### fn get(self, slice: &ByteStr) -> 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.
Source§

#### fn get_mut(self, slice: &mut ByteStr) -> 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.
Source§

#### unsafe fn get_unchecked(self, slice: *const ByteStr) -> *const Self::Output

🔬This is a nightly-only experimental API. (`slice_index_methods`)
Returns a pointer to the output at this location, without performing any bounds checking. Read more
Source§

#### unsafe fn get_unchecked_mut(self, slice: *mut ByteStr) -> *mut Self::Output

🔬This is a nightly-only experimental API. (`slice_index_methods`)
Returns a mutable pointer to the output at this location, without performing any bounds checking. Read more
Source§

#### fn index(self, slice: &ByteStr) -> &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.
Source§

#### fn index_mut(self, slice: &mut ByteStr) -> &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.
1.73.0 · Source§

### impl SliceIndex<str> for (Bound<usize>, Bound<usize>)

Implements substring slicing for arbitrary bounds.

Returns a slice of the given string bounded by the byte indices provided by each bound.

This operation is O(1).

#### §Panics

Panics if `begin` or `end` (if it exists and once adjusted for inclusion/exclusion) does not point to the starting byte offset of a character (as defined by `is_char_boundary`), if `begin > end`, or if `end > len`.

Source§

#### type Output = str

The output type returned by methods.
Source§

#### fn get(self, slice: &str) -> Option<&str>

🔬This is a nightly-only experimental API. (`slice_index_methods`)
Returns a shared reference to the output at this location, if in bounds.
Source§

#### fn get_mut(self, slice: &mut str) -> Option<&mut str>

🔬This is a nightly-only experimental API. (`slice_index_methods`)
Returns a mutable reference to the output at this location, if in bounds.
Source§

#### unsafe fn get_unchecked(self, slice: *const str) -> *const str

🔬This is a nightly-only experimental API. (`slice_index_methods`)
Returns a pointer to the output at this location, without performing any bounds checking. Read more
Source§

#### unsafe fn get_unchecked_mut(self, slice: *mut str) -> *mut str

🔬This is a nightly-only experimental API. (`slice_index_methods`)
Returns a mutable pointer to the output at this location, without performing any bounds checking. Read more
Source§

#### fn index(self, slice: &str) -> &str

🔬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.
Source§

#### fn index_mut(self, slice: &mut str) -> &mut str

🔬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.
Source§

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

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

1.0.0 · Source§

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

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

Source§

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

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

Source§

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

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

## Auto Trait Implementations§

§

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

§

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

§

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

§

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

§

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

§

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

## Blanket Implementations§

Source§

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

Source§

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

Gets the `TypeId` of `self`. Read more
Source§

### impl<T> Borrow<T> for T
where T: ?Sized,

Source§

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

Immutably borrows from an owned value. Read more
Source§

### impl<T> BorrowMut<T> for T
where T: ?Sized,

Source§

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

Mutably borrows from an owned value. Read more
Source§

### impl<T> CloneToUninit for T
where T: Clone,

Source§

#### unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (`clone_to_uninit` #126799)
Performs copy-assignment from `self` to `dest`. Read more
Source§

### impl<T> From<T> for T

Source§

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

Returns the argument unchanged.

Source§

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

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.

Source§

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

Source§

#### type Error = Infallible

The type returned in the event of a conversion error.
Source§

#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
Source§

### impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

Source§

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

The type returned in the event of a conversion error.
Source§

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

Performs the conversion.