# Struct core::ops::Range

1.0.0 · source · []
``````pub struct Range<Idx> {
pub start: Idx,
pub end: Idx,
}``````
Expand description

A (half-open) range bounded inclusively below and exclusively above (`start..end`).

The range `start..end` contains all values with `start <= x < end`. It is empty if `start >= end`.

## Examples

The `start..end` syntax is a `Range`:

``````assert_eq!((3..5), std::ops::Range { start: 3, end: 5 });
assert_eq!(3 + 4 + 5, (3..6).sum());``````
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``````let arr = [0, 1, 2, 3, 4];
assert_eq!(arr[ ..  ], [0, 1, 2, 3, 4]);
assert_eq!(arr[ .. 3], [0, 1, 2      ]);
assert_eq!(arr[ ..=3], [0, 1, 2, 3   ]);
assert_eq!(arr[1..  ], [   1, 2, 3, 4]);
assert_eq!(arr[1.. 3], [   1, 2      ]); // This is a `Range`
assert_eq!(arr[1..=3], [   1, 2, 3   ]);``````
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## Fields

`start: Idx`

The lower bound of the range (inclusive).

`end: Idx`

The upper bound of the range (exclusive).

## Implementations

Returns `true` if `item` is contained in the range.

##### Examples
``````assert!(!(3..5).contains(&2));
assert!( (3..5).contains(&3));
assert!( (3..5).contains(&4));
assert!(!(3..5).contains(&5));

assert!(!(3..3).contains(&3));
assert!(!(3..2).contains(&3));

assert!( (0.0..1.0).contains(&0.5));
assert!(!(0.0..1.0).contains(&f32::NAN));
assert!(!(0.0..f32::NAN).contains(&0.5));
assert!(!(f32::NAN..1.0).contains(&0.5));``````
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Returns `true` if the range contains no items.

##### Examples
``````assert!(!(3..5).is_empty());
assert!( (3..3).is_empty());
assert!( (3..2).is_empty());``````
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The range is empty if either side is incomparable:

``````assert!(!(3.0..5.0).is_empty());
assert!( (3.0..f32::NAN).is_empty());
assert!( (f32::NAN..5.0).is_empty());``````
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## Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from `source`. Read more

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

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

Returns the `n`th element from the end of the iterator. Read more

🔬 This is a nightly-only experimental API. (`iter_advance_by` #77404)

Advances the iterator from the back by `n` elements. Read more

This is the reverse version of `Iterator::try_fold()`: it takes elements starting from the back of the iterator. Read more

An iterator method that reduces the iterator’s elements to a single, final value, starting from the back. Read more

Searches for an element of an iterator from the back that satisfies a predicate. Read more

Returns the exact length of the iterator. Read more

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

Returns `true` if the iterator is empty. Read more

Returns the exact length of the iterator. Read more

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

Returns `true` if the iterator is empty. Read more

Returns the exact length of the iterator. Read more

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

Returns `true` if the iterator is empty. Read more

Returns the exact length of the iterator. Read more

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

Returns `true` if the iterator is empty. Read more

Returns the exact length of the iterator. Read more

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

Returns `true` if the iterator is empty. Read more

Returns the exact length of the iterator. Read more

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

Returns `true` if the iterator is empty. Read more

Returns the exact length of the iterator. Read more

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

Returns `true` if the iterator is empty. Read more

Returns the exact length of the iterator. Read more

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

Returns `true` if the iterator is empty. Read more

Feeds this value into the given `Hasher`. Read more

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

The type of the elements being iterated over.

Returns the bounds on the remaining length of the iterator. Read more

Returns the `n`th element of the iterator. Read more

Consumes the iterator, returning the last element. Read more

Returns the minimum element of an iterator. Read more

Returns the maximum element of an iterator. Read more

🔬 This is a nightly-only experimental API. (`is_sorted` #53485)

Checks if the elements of this iterator are sorted. Read more

🔬 This is a nightly-only experimental API. (`iter_advance_by` #77404)

Advances the iterator by `n` elements. Read more

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

Creates an iterator starting at the same point, but stepping by the given amount at each iteration. Read more

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

‘Zips up’ two iterators into a single iterator of pairs. Read more

🔬 This is a nightly-only experimental API. (`iter_intersperse` #79524)

Creates a new iterator which places a copy of `separator` between adjacent items of the original iterator. Read more

🔬 This is a nightly-only experimental API. (`iter_intersperse` #79524)

Creates a new iterator which places an item generated by `separator` between adjacent items of the original iterator. Read more

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

Calls a closure on each element of an iterator. Read more

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

Creates an iterator that both filters and maps. Read more

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

Creates an iterator which can use the `peek` and `peek_mut` methods to look at the next element of the iterator without consuming it. See their documentation for more information. Read more

Creates an iterator that `skip`s elements based on a predicate. Read more

Creates an iterator that yields elements based on a predicate. Read more

Creates an iterator that both yields elements based on a predicate and maps. Read more

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

Creates an iterator that yields the first `n` elements, or fewer if the underlying iterator ends sooner. Read more

An iterator adapter similar to `fold` that holds internal state and produces a new iterator. Read more

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

Creates an iterator that flattens nested structure. Read more

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

Does something with each element of an iterator, passing the value on. Read more

Borrows an iterator, rather than consuming it. Read more

Transforms an iterator into a collection. Read more

🔬 This is a nightly-only experimental API. (`iterator_try_collect` #94047)

Fallibly transforms an iterator into a collection, short circuiting if a failure is encountered. Read more

🔬 This is a nightly-only experimental API. (`iter_collect_into` #94780)

Collects all the items from an iterator into a collection. Read more

Consumes an iterator, creating two collections from it. Read more

🔬 This is a nightly-only experimental API. (`iter_partition_in_place` #62543)

Reorders the elements of this iterator in-place according to the given predicate, such that all those that return `true` precede all those that return `false`. Returns the number of `true` elements found. Read more

🔬 This is a nightly-only experimental API. (`iter_is_partitioned` #62544)

Checks if the elements of this iterator are partitioned according to the given predicate, such that all those that return `true` precede all those that return `false`. Read more

An iterator method that applies a function as long as it returns successfully, producing a single, final value. Read more

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

Folds every element into an accumulator by applying an operation, returning the final result. Read more

Reduces the elements to a single one, by repeatedly applying a reducing operation. Read more

🔬 This is a nightly-only experimental API. (`iterator_try_reduce` #87053)

Reduces the elements to a single one by repeatedly applying a reducing operation. If the closure returns a failure, the failure is propagated back to the caller immediately. Read more

Tests if every element of the iterator matches a predicate. Read more

Tests if any element of the iterator matches a predicate. Read more

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

Applies function to the elements of iterator and returns the first non-none result. Read more

🔬 This is a nightly-only experimental API. (`try_find` #63178)

Applies function to the elements of iterator and returns the first true result or the first error. Read more

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

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

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

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

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

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

Reverses an iterator’s direction. Read more

Converts an iterator of pairs into a pair of containers. Read more

Creates an iterator which copies all of its elements. Read more

Creates an iterator which `clone`s all of its elements. Read more

Repeats an iterator endlessly. Read more

Sums the elements of an iterator. Read more

Iterates over the entire iterator, multiplying all the elements Read more

Lexicographically compares the elements of this `Iterator` with those of another. Read more

🔬 This is a nightly-only experimental API. (`iter_order_by` #64295)

Lexicographically compares the elements of this `Iterator` with those of another with respect to the specified comparison function. Read more

Lexicographically compares the elements of this `Iterator` with those of another. Read more

🔬 This is a nightly-only experimental API. (`iter_order_by` #64295)

Lexicographically compares the elements of this `Iterator` with those of another with respect to the specified comparison function. Read more

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

🔬 This is a nightly-only experimental API. (`iter_order_by` #64295)

Determines if the elements of this `Iterator` are equal to those of another with respect to the specified equality function. Read more

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

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

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

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

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

🔬 This is a nightly-only experimental API. (`is_sorted` #53485)

Checks if the elements of this iterator are sorted using the given comparator function. Read more

🔬 This is a nightly-only experimental API. (`is_sorted` #53485)

Checks if the elements of this iterator are sorted using the given key extraction function. Read more

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

This method tests for `!=`.

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

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

The output type returned by methods.

🔬 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

🔬 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

🔬 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

🔬 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

🔬 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

🔬 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

Implements substring slicing with syntax `&self[begin .. end]` or `&mut self[begin .. end]`.

Returns a slice of the given string from the byte range [`begin`, `end`).

This operation is O(1).

Prior to 1.20.0, these indexing operations were still supported by direct implementation of `Index` and `IndexMut`.

#### Panics

Panics if `begin` or `end` does not point to the starting byte offset of a character (as defined by `is_char_boundary`), if `begin > end`, or if `end > len`.

#### Examples

``````let s = "Löwe 老虎 Léopard";
assert_eq!(&s[0 .. 1], "L");

assert_eq!(&s[1 .. 9], "öwe 老");

// these will panic:
// byte 2 lies within `ö`:
// &s[2 ..3];

// byte 8 lies within `老`
// &s[1 .. 8];

// byte 100 is outside the string
// &s[3 .. 100];``````
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The output type returned by methods.

🔬 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

🔬 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

🔬 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

🔬 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

🔬 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

🔬 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

## Blanket Implementations

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

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls `U::from(self)`.

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

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.