Struct std::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

The upper bound of the range (exclusive).

Methods

impl<Idx> RangeTo<Idx> where
    Idx: PartialOrd<Idx>,  [src]

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

#![feature(range_contains)]

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

Trait Implementations

impl Index<RangeTo<usize>> for String [src]

type Output = str

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

impl<T> Index<RangeTo<usize>> for Vec<T> [src]

type Output = [T]

fn index(&self, index: RangeTo<usize>) -> &[T] [src]

impl<T> RangeArgument<T> for RangeTo<T> [src]

fn start(&self) -> Bound<&T> [src]

fn end(&self) -> Bound<&T> [src]

impl<T> IndexMut<RangeTo<usize>> for Vec<T> [src]

fn index_mut(&mut self, index: RangeTo<usize>) -> &mut [T] [src]

impl IndexMut<RangeTo<usize>> for String

1.3.0

[src]

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

impl<Idx> Clone for RangeTo<Idx> where
    Idx: Clone,  [src]

fn clone(&self) -> RangeTo<Idx> [src]

fn clone_from(&mut self, source: &Self) [src]

impl<Idx> Eq for RangeTo<Idx> where
    Idx: Eq,  [src]

impl<Idx> Hash for RangeTo<Idx> where
    Idx: Hash,  [src]

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

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

1.3.0

[src]

impl IndexMut<RangeTo<usize>> for str

1.3.0

[src]

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 [src]

impl<Idx> Copy for RangeTo<Idx> where
    Idx: Copy,  [src]

impl<Idx> PartialEq<RangeTo<Idx>> for RangeTo<Idx> where
    Idx: PartialEq<Idx>,  [src]

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

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

impl Index<RangeTo<usize>> for str [src]

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

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

impl SliceIndex<str> for RangeTo<usize>

1.20.0

[src]

type Output = str

fn get(
    self,
    slice: &str
) -> Option<&<RangeTo<usize> as SliceIndex<str>>::Output> [src]

fn get_mut(
    self,
    slice: &mut str
) -> Option<&mut <RangeTo<usize> as SliceIndex<str>>::Output> [src]

unsafe fn get_unchecked(
    self,
    slice: &str
) -> &<RangeTo<usize> as SliceIndex<str>>::Output [src]

unsafe fn get_unchecked_mut(
    self,
    slice: &mut str
) -> &mut <RangeTo<usize> as SliceIndex<str>>::Output [src]

fn index(self, slice: &str) -> &<RangeTo<usize> as SliceIndex<str>>::Output [src]

fn index_mut(
    self,
    slice: &mut str
) -> &mut <RangeTo<usize> as SliceIndex<str>>::Output [src]

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

1.15.0

[src]

type Output = [T]

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

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

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

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

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

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

impl<Idx> Debug for RangeTo<Idx> where
    Idx: Debug,  [src]

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