# 1.0.0[−][src]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 });Run

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 {
        // ...
    }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]

####

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

[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)]

    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));Run

## Trait Implementations

###

`impl<Idx> Debug for RangeTo<Idx> where Idx: Debug,`

[src]

####

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

[src]

Formats the value using the given formatter. 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]`.

####

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

[src]

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

###

`impl<Idx> Copy for RangeTo<Idx> where Idx: Copy,`

[src]

###

`impl<Idx> Eq for RangeTo<Idx> where Idx: Eq,`

[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`

The returned type after indexing.

####

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

[src]

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

###

`impl<Idx> Clone for RangeTo<Idx> where Idx: Clone,`

[src]

####

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

[src]

Returns a copy of the value. Read more

####

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

[src]

Performs copy-assignment from `source`. Read more

###

`impl<Idx> PartialEq<RangeTo<Idx>> for RangeTo<Idx> where Idx: PartialEq<Idx>,`

[src]

####

`fn eq(&self, other: &RangeTo<Idx>) -> bool`

[src]

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

####

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

[src]

This method tests for `!=`.

###

`impl<Idx> Hash for RangeTo<Idx> where Idx: Hash,`

[src]

####

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

[src]

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

####

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

1.3.0
[src]

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

###

`impl SliceIndex<str> for RangeTo<usize>`

1.20.0
[src]

#### `type Output = str`

The output type returned by methods.

####

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

[src]

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

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

####

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

[src]

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

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

####

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

[src]

🔬 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. Read more

####

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

[src]

🔬 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. Read more

####

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

[src]

🔬 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. Read more

####

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

[src]

🔬 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. Read more

###

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

1.15.0
[src]

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

The output type returned by methods.

####

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

[src]

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

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]>`

[src]

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

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

####
ⓘImportant traits for &'a [u8]

### Important traits for &'a [u8]

`impl<'a> Read for &'a [u8]impl<'a> Write for &'a mut [u8]`

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

[src]

🔬 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. Read more

####
ⓘImportant traits for &'a [u8]

### Important traits for &'a [u8]

`impl<'a> Read for &'a [u8]impl<'a> Write for &'a mut [u8]`

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

[src]

🔬 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. Read more

####
ⓘImportant traits for &'a [u8]

### Important traits for &'a [u8]

`impl<'a> Read for &'a [u8]impl<'a> Write for &'a mut [u8]`

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

[src]

🔬 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. Read more

####
ⓘImportant traits for &'a [u8]

### Important traits for &'a [u8]

`impl<'a> Read for &'a [u8]impl<'a> Write for &'a mut [u8]`

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

[src]

🔬 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. Read more

###

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

1.28.0
[src]

####

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

[src]

Start index bound. Read more

####

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

[src]

End index bound. Read more

####

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

[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. Read more

###

`impl<T> RangeBounds<T> for RangeTo<T>`

1.28.0
[src]

####

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

[src]

Start index bound. Read more

####

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

[src]

End index bound. Read more

####

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

[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. Read more

###

`impl Index<RangeTo<usize>> for String`

[src]

#### `type Output = str`

The returned type after indexing.

####

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

[src]

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

###

`impl IndexMut<RangeTo<usize>> for String`

1.3.0
[src]

####

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

[src]

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

## Auto Trait Implementations

###

`impl<Idx> Send for RangeTo<Idx> where Idx: Send,`

###

`impl<Idx> Sync for RangeTo<Idx> where Idx: Sync,`

## Blanket Implementations

###

`impl<T> From for T`

[src]

####

`fn from(t: T) -> T`

[src]

Performs the conversion.

###

`impl<T, U> TryFrom for T where T: From<U>,`

[src]

#### `type Error = !`

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

####

`fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`

[src]

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

###

`impl<T, U> TryInto for T where U: TryFrom<T>,`

[src]

#### `type Error = <U as TryFrom<T>>::Error`

🔬 This is a nightly-only experimental API. (`try_from` #33417)

The type returned in the event of a conversion error.

####

`fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`

[src]

🔬 This is a nightly-only experimental API. (`try_from` #33417)

Performs the conversion.

###

`impl<T, U> Into for T where U: From<T>,`

[src]

####

`fn into(self) -> U`

[src]

Performs the conversion.

###

`impl<T> Borrow for T where T: ?Sized,`

[src]

####
ⓘImportant traits for &'a mut I

### Important traits for &'a mut I

`impl<'a, I> Iterator for &'a mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'a, R: Read + ?Sized> Read for &'a mut Rimpl<'a, W: Write + ?Sized> Write for &'a mut W`

`fn borrow(&self) -> &T`

[src]

Immutably borrows from an owned value. Read more

###

`impl<T> BorrowMut for T where T: ?Sized,`

[src]

####
ⓘImportant traits for &'a mut I

### Important traits for &'a mut I

`impl<'a, I> Iterator for &'a mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'a, R: Read + ?Sized> Read for &'a mut Rimpl<'a, W: Write + ?Sized> Write for &'a mut W`

`fn borrow_mut(&mut self) -> &mut T`

[src]

Mutably borrows from an owned value. Read more

###

`impl<T> Any for T where T: 'static + ?Sized,`

[src]

####

`fn get_type_id(&self) -> TypeId`

[src]

🔬 This is a nightly-only experimental API. (`get_type_id` #27745)

this method will likely be replaced by an associated static

Gets the `TypeId` of `self`. Read more

###

`impl<T> ToOwned for T where T: Clone,`

[src]

#### `type Owned = T`

####

`fn to_owned(&self) -> T`

[src]

Creates owned data from borrowed data, usually by cloning. Read more

####

`fn clone_into(&self, target: &mut T)`

[src]

🔬 This is a nightly-only experimental API. (`toowned_clone_into` #41263)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

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