Struct core::ops::RangeTo1.0.0 [] [src]

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:

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

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

fn main() { for i in ..5 { // ... } }
for i in ..5 {
    // ...
}Run

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

fn main() { 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 ]); }
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  ]);Run

Fields

The upper bound of the range (exclusive).

Methods

impl<Idx: PartialOrd<Idx>> RangeTo<Idx>
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Unstable (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)); }
#![feature(range_contains)]
fn main() {
    assert!(   (..5).contains(-1_000_000_000));
    assert!(   (..5).contains(4));
    assert!( ! (..5).contains(5));
}Run

Trait Implementations

impl<Idx: Copy> Copy for RangeTo<Idx>
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impl<Idx: Clone> Clone for RangeTo<Idx>
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Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

impl<Idx: PartialEq> PartialEq for RangeTo<Idx>
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This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl<Idx: Eq> Eq for RangeTo<Idx>
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impl<Idx: Hash> Hash for RangeTo<Idx>
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Feeds this value into the state given, updating the hasher as necessary.

Feeds a slice of this type into the state provided.

impl<Idx: Debug> Debug for RangeTo<Idx>
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Formats the value using the given formatter.