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/Rust

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:

This example deliberately fails to 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]

[src]

🔬 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)]

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

Trait Implementations

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

The returned type after indexing.

[src]

Performs the indexing (container[index]) operation.

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

The returned type after indexing.

[src]

Performs the indexing (container[index]) operation.

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

[src]

🔬 This is a nightly-only experimental API. (collections_range #30877)waiting for dust to settle on inclusive ranges

Start index bound. Read more

[src]

🔬 This is a nightly-only experimental API. (collections_range #30877)waiting for dust to settle on inclusive ranges

End index bound. Read more

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

[src]

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

impl IndexMut<RangeTo<usize>> for String
1.3.0
[src]

[src]

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

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

[src]

Returns a copy of the value. Read more

[src]

Performs copy-assignment from source. Read more

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

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

[src]

Feeds this value into the given [Hasher]. Read more

1.3.0
[src]

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

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].

[src]

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

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

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

[src]

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

[src]

This method tests for !=.

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].

The returned type after indexing.

[src]

Performs the indexing (container[index]) operation.

impl SliceIndex<str> for RangeTo<usize>
1.20.0
[src]

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

The output type returned by methods.

[src]

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

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

[src]

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

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

[src]

🔬 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. Read more

[src]

🔬 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. Read more

[src]

🔬 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. Read more

[src]

🔬 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. Read more

impl<T> SliceIndex<[T]> for RangeTo<usize>
1.15.0
[src]

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

The output type returned by methods.

[src]

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

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

[src]

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

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

[src]

🔬 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. Read more

[src]

🔬 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. Read more

[src]

🔬 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. Read more

[src]

🔬 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. Read more

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

[src]

Formats the value using the given formatter. Read more

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/ops/struct.RangeTo.html