Struct std::ops::RangeTo

pub struct RangeTo<Idx> {
    pub end: Idx,
}

A range which is only bounded above: { x | x < end }. Use ..end (two dots) for its shorthand.

See the contains() method for its characterization.

It cannot serve as an iterator because it doesn't have a starting point.

Examples

The ..{integer} syntax is a RangeTo:

assert_eq!((..5), std::ops::RangeTo{ end: 5 });

It does not have an IntoIterator implementation, so you can't use it in a for loop directly. This won't compile:

for i in ..5 {
    // ...
}

When used as a slicing index, RangeTo produces a slice of all array elements before the index indicated by end.

let arr = [0, 1, 2, 3];
assert_eq!(arr[ .. ], [0,1,2,3]);
assert_eq!(arr[ ..3], [0,1,2  ]);  // RangeTo
assert_eq!(arr[1.. ], [  1,2,3]);
assert_eq!(arr[1..3], [  1,2  ]);

Fields

end: Idx

The upper bound of the range (exclusive).

Methods

impl<Idx> RangeTo<Idx> where Idx: PartialOrd<Idx>

fn contains(&self, item: Idx) -> bool

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

recently added as per RFC

Examples

#![feature(range_contains)]
fn main() {
    assert!(   (..5).contains(-1_000_000_000));
    assert!(   (..5).contains(4));
    assert!( ! (..5).contains(5));
}

Trait Implementations

impl<Idx> Hash for RangeTo<Idx> where Idx: Hash

fn hash<__HIdx>(&self, __arg_0: &mut __HIdx) where __HIdx: Hasher

Feeds this value into the state given, updating the hasher as necessary.

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

Feeds a slice of this type into the state provided.

impl<T> SliceIndex<T> for RangeTo<usize>

type Output = [T]

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

The output type returned by methods.

fn get(self, slice: &[T]) -> Option<&[T]>

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

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

fn get_mut(self, slice: &mut [T]) -> Option<&mut [T]>

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

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

unsafe fn get_unchecked(self, slice: &[T]) -> &[T]

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

Returns a shared reference to the output at this location, without performing any bounds checking.

unsafe fn get_unchecked_mut(self, slice: &mut [T]) -> &mut [T]

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

Returns a mutable reference to the output at this location, without performing any bounds checking.

fn index(self, slice: &[T]) -> &[T]

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

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

fn index_mut(self, slice: &mut [T]) -> &mut [T]

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

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

impl<Idx> PartialEq<RangeTo<Idx>> for RangeTo<Idx> where Idx: PartialEq<Idx>

fn eq(&self, __arg_0: &RangeTo<Idx>) -> bool

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

fn ne(&self, __arg_0: &RangeTo<Idx>) -> bool

This method tests for !=.

impl<Idx> Clone for RangeTo<Idx> where Idx: Clone

fn clone(&self) -> RangeTo<Idx>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<Idx> Eq for RangeTo<Idx> where Idx: Eq

impl<Idx> Copy for RangeTo<Idx> where Idx: Copy

impl<Idx> Debug for RangeTo<Idx> where Idx: Debug

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

Formats the value using the given formatter.

impl<T> RangeArgument<T> for RangeTo<T>

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

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

waiting for dust to settle on inclusive ranges

Start index bound

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

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

waiting for dust to settle on inclusive ranges

End index bound