Struct RangeTo

pub struct RangeTo<Idx> {
    pub end: Idx,
}

Available on crate feature std only.

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, 4];
assert_eq!(arr[ ..  ], [0, 1, 2, 3, 4]);
assert_eq!(arr[ .. 3], [0, 1, 2      ]); // This is a `RangeTo`
assert_eq!(arr[ ..=3], [0, 1, 2, 3   ]);
assert_eq!(arr[1..  ], [   1, 2, 3, 4]);
assert_eq!(arr[1.. 3], [   1, 2      ]);
assert_eq!(arr[1..=3], [   1, 2, 3   ]);

Fields

end: Idx

The upper bound of the range (exclusive).

Implementations

impl<Idx> RangeTo<Idx>

where Idx: PartialOrd,

pub fn contains<U>(&self, item: &U) -> bool

where Idx: PartialOrd<U>, U: PartialOrd<Idx> + ?Sized,

Returns true if item is contained in the range.

Examples

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));

Trait Implementations

impl<T> Archive for RangeTo<T>

where T: Archive,

type Archived = ArchivedRangeTo<<T as Archive>::Archived>

The archived representation of this type.

type Resolver = RangeTo<<T as Archive>::Resolver>

The resolver for this type. It must contain all the additional information from serializing needed to make the archived type from the normal type.

fn resolve( &self, resolver: <RangeTo<T> as Archive>::Resolver, out: Place<<RangeTo<T> as Archive>::Archived>, )

Creates the archived version of this value at the given position and writes it to the given output.

const COPY_OPTIMIZATION: CopyOptimization<Self> = _

An optimization flag that allows the bytes of this type to be copied directly to a writer instead of calling serialize.

impl<T, C> CheckBytes<C> for RangeTo<T>

where T: CheckBytes<C>, C: Fallible + ?Sized, <C as Fallible>::Error: Trace,

unsafe fn check_bytes( value: *const RangeTo<T>, context: &mut C, ) -> Result<(), <C as Fallible>::Error>

Checks whether the given pointer points to a valid value within the given context.

impl<Idx> Clone for RangeTo<Idx>

where Idx: Clone,

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<Idx> Debug for RangeTo<Idx>

where Idx: Debug,

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

Formats the value using the given formatter.

impl<Idx> Hash for RangeTo<Idx>

where Idx: Hash,

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Index<RangeTo<usize>> for ArchivedString

type Output = str

The returned type after indexing.

fn index( &self, index: RangeTo<usize>, ) -> &<ArchivedString as Index<RangeTo<usize>>>::Output

Performs the indexing (container[index]) operation.

impl<K, V, S> Index<RangeTo<usize>> for IndexMap<K, V, S>

type Output = Slice<K, V>

The returned type after indexing.

fn index( &self, range: RangeTo<usize>, ) -> &<IndexMap<K, V, S> as Index<RangeTo<usize>>>::Output

Performs the indexing (container[index]) operation.

impl<T, S> Index<RangeTo<usize>> for IndexSet<T, S>

type Output = Slice<T>

The returned type after indexing.

fn index( &self, range: RangeTo<usize>, ) -> &<IndexSet<T, S> as Index<RangeTo<usize>>>::Output

Performs the indexing (container[index]) operation.

impl<K, V> Index<RangeTo<usize>> for Slice<K, V>

type Output = Slice<K, V>

The returned type after indexing.

fn index(&self, range: RangeTo<usize>) -> &Slice<K, V>

Performs the indexing (container[index]) operation.

impl<T> Index<RangeTo<usize>> for Slice<T>

type Output = Slice<T>

The returned type after indexing.

fn index( &self, range: RangeTo<usize>, ) -> &<Slice<T> as Index<RangeTo<usize>>>::Output

Performs the indexing (container[index]) operation.

impl Index<RangeTo<usize>> for UninitSlice

type Output = UninitSlice

The returned type after indexing.

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

Performs the indexing (container[index]) operation.

impl<K, V, S> IndexMut<RangeTo<usize>> for IndexMap<K, V, S>

fn index_mut( &mut self, range: RangeTo<usize>, ) -> &mut <IndexMap<K, V, S> as Index<RangeTo<usize>>>::Output

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

impl<K, V> IndexMut<RangeTo<usize>> for Slice<K, V>

fn index_mut(&mut self, range: RangeTo<usize>) -> &mut Slice<K, V>

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

impl IndexMut<RangeTo<usize>> for UninitSlice

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

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

impl<T, U> PartialEq<RangeTo<T>> for ArchivedRangeTo<U>

where U: PartialEq<T>,

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

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<Idx> PartialEq for RangeTo<Idx>

where Idx: PartialEq,

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

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> RangeBounds<T> for RangeTo<&T>

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

Start index bound.

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

End index bound.

fn contains<U>(&self, item: &U) -> bool

where T: PartialOrd<U>, U: PartialOrd<T> + ?Sized,

Returns true if item is contained in the range.

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

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

Start index bound.

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

End index bound.

fn contains<U>(&self, item: &U) -> bool

where T: PartialOrd<U>, U: PartialOrd<T> + ?Sized,

Returns true if item is contained in the range.

impl<T, S> Serialize<S> for RangeTo<T>

where T: Serialize<S>, S: Fallible + ?Sized,

fn serialize( &self, serializer: &mut S, ) -> Result<<RangeTo<T> as Archive>::Resolver, <S as Fallible>::Error>

Writes the dependencies for the object and returns a resolver that can create the archived type.

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

The methods index and index_mut panic if the end of the range is out of bounds.

type Output = [T]

The output type returned by methods.

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

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

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

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

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

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

unsafe fn get_unchecked(self, slice: *const [T]) -> *const [T]

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

Returns a pointer to the output at this location, without performing any bounds checking.

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

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

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

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

🔬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.

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

🔬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.

impl SliceIndex<str> for RangeTo<usize>

Implements substring slicing with syntax &self[.. end] or &mut self[.. end].

Returns a slice of the given string from the byte range [0, end). Equivalent to &self[0 .. end] or &mut self[0 .. end].

This operation is O(1).

Prior to 1.20.0, these indexing operations were still supported by direct implementation of Index and IndexMut.

Panics

Panics if end does not point to the starting byte offset of a character (as defined by is_char_boundary), or if end > len.

type Output = str

The output type returned by methods.

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

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

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

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

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

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

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

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

Returns a pointer to the output at this location, without performing any bounds checking.

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

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

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

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

🔬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.

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

🔬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.

impl<Idx> Copy for RangeTo<Idx>

where Idx: Copy,

impl<Idx> Eq for RangeTo<Idx>

where Idx: Eq,

impl<T> OneSidedRange<T> for RangeTo<T>

where RangeTo<T>: RangeBounds<T>,

impl<Idx> StructuralPartialEq for RangeTo<Idx>