Struct core::ops::RangeTo

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

A range only bounded exclusively above (..end).

The RangeTo ..end contains all values with x < end. It cannot serve as an Iterator because it doesn't have a starting point.

Examples

The ..end 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:

// error[E0277]: the trait bound `std::ops::RangeTo<{integer}>:
// std::iter::Iterator` is not satisfied
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>

pub fn contains<U: ?Sized>(&self, item: &U) -> bool where     Idx: PartialOrd<U>,     U: PartialOrd<Idx>,

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

recently added as per RFC

Returns true if item is contained in the range.

Examples

#![feature(range_contains)]

use std::f32;

assert!( (..5).contains(&-1_000_000_000));
assert!( (..5).contains(&4));
assert!(!(..5).contains(&5));

assert!( (..1.0).contains(&0.5));
assert!(!(..1.0).contains(&f32::NAN));
assert!(!(..f32::NAN).contains(&0.5));

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, other: &RangeTo<Idx>) -> bool

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

fn ne(&self, other: &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, state: &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> RangeBounds<T> for RangeTo<T>

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

Start index bound.

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

End index bound.

fn contains<U: ?Sized>(&self, item: &U) -> bool where     T: PartialOrd<U>,     U: PartialOrd<T>,

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

recently added as per RFC

Returns true if item is contained in the range.

impl<'a, T> RangeBounds<T> for RangeTo<&'a T>

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

Start index bound.

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

End index bound.

fn contains<U: ?Sized>(&self, item: &U) -> bool where     T: PartialOrd<U>,     U: PartialOrd<T>,

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

recently added as per RFC

Returns true if item is contained in the range.

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

type Output = [T]

The output type returned by methods.

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

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

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_index_methods)

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_index_methods)

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_index_methods)

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_index_methods)

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_index_methods)

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

impl Index<RangeTo<usize>> for str

Implements substring slicing with syntax &self[.. end].

Returns a slice of the string from the beginning to byte offset end.

Equivalent to &self[0 .. end].

type Output = str

The returned type after indexing.

fn index(&self, index: RangeTo<usize>) -> &str

Performs the indexing (container[index]) operation.

impl IndexMut<RangeTo<usize>> for str

Implements mutable substring slicing with syntax &mut self[.. end].

Returns a mutable slice of the string from the beginning to byte offset end.

Equivalent to &mut self[0 .. end].

fn index_mut(&mut self, index: RangeTo<usize>) -> &mut str

Performs the mutable indexing (container[index]) operation.

impl SliceIndex<str> for RangeTo<usize>

type Output = str

The output type returned by methods.

fn get(self, slice: &str) -> 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.

fn get_mut(self, slice: &mut str) -> 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.

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

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

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

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