std::ops::RangeTo - Rust
Description: API documentation for the Rust `RangeTo` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, RangeTo

# Struct std::ops::RangeTo 1.0.0 [−] [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`:

    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:

    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`.

    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

`end: Idx`

The upper bound of the range (exclusive).

## Methods

### `impl<Idx> RangeTo<Idx> where Idx: PartialOrd<Idx>`
[src]

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

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));
    }Run

## Trait Implementations

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

#### `fn end(&self) -> Option<&T>`

Unstable (`collections_range` #30877)

: waiting for dust to settle on inclusive ranges

End index (exclusive) Read more

#### `fn start(&self) -> Option<&T>`

Unstable (`collections_range` #30877)

: waiting for dust to settle on inclusive ranges

Start index (inclusive) Read more

### `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`

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

#### `fn ne(&self, __arg_0: &RangeTo<Idx>) -> bool`

This method tests for `!=`.

### `impl<T> SliceIndex<T> for RangeTo<usize>`
1.13.0
[src]

#### `type Output = [T]`

Unstable (`slice_get_slice` #35729)

The output type returned by methods.

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

Unstable (`slice_get_slice` #35729)

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

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

Unstable (`slice_get_slice` #35729)

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

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

Unstable (`slice_get_slice` #35729)

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

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

Unstable (`slice_get_slice` #35729)

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

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

Unstable (`slice_get_slice` #35729)

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

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

Unstable (`slice_get_slice` #35729)

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

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

#### `fn clone(&self) -> RangeTo<Idx>`

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`

Performs copy-assignment from `source`. Read more

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

#### `fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>`

Formats the value using the given formatter.

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

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

Feeds this value into the state given, updating the hasher as necessary.

#### `fn hash_slice<H>(data: &[Self], state: &mut H) where H: Hasher`
1.3.0

Feeds a slice of this type into the state provided.

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

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