Struct core::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: PartialOrd<Idx>> RangeTo<Idx>

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

🔬 This is a nightly-only experimental API. (range_contains #32311)

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: Copy> Copy for RangeTo<Idx>

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

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: PartialEq> PartialEq for RangeTo<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: Eq> Eq for RangeTo<Idx>

impl<Idx: Hash> Hash for RangeTo<Idx>

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

Feeds this value into the given [Hasher].

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

Feeds a slice of this type into the given [Hasher].

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

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

Formats the value using the given formatter.

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

type Output = [T]

🔬 This is a nightly-only experimental API. (slice_get_slice #35729)

The output type returned by methods.

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

🔬 This is a nightly-only experimental API. (slice_get_slice #35729)

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 #35729)

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 #35729)

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 #35729)

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 #35729)

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 #35729)

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

impl SliceIndex<str> for RangeTo<usize>

type Output = str

🔬 This is a nightly-only experimental API. (slice_get_slice #35729)

The output type returned by methods.

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

🔬 This is a nightly-only experimental API. (slice_get_slice #35729)

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

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

🔬 This is a nightly-only experimental API. (slice_get_slice #35729)

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

unsafe fn get_unchecked(self, slice: &str) -> &Self::Output

🔬 This is a nightly-only experimental API. (slice_get_slice #35729)

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

unsafe fn get_unchecked_mut(self, slice: &mut str) -> &mut Self::Output

🔬 This is a nightly-only experimental API. (slice_get_slice #35729)

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

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

🔬 This is a nightly-only experimental API. (slice_get_slice #35729)

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

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

🔬 This is a nightly-only experimental API. (slice_get_slice #35729)

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