Struct std::ops::RangeFrom

pub struct RangeFrom<Idx> {
    pub start: Idx,
}

[−] Expand description

A range which is only bounded below: { x | start <= x }. Use start.. for its shorthand.

See the contains() method for its characterization.

Note: Currently, no overflow checking is done for the iterator implementation; if you use an integer range and the integer overflows, it might panic in debug mode or create an endless loop in release mode. This overflow behavior might change in the future.

Examples

fn main() {
    assert_eq!((2..), std::ops::RangeFrom{ start: 2 });
    assert_eq!(2+3+4, (2..).take(3).sum());

    let arr = [0, 1, 2, 3];
    assert_eq!(arr[ .. ], [0,1,2,3]);
    assert_eq!(arr[ ..3], [0,1,2  ]);
    assert_eq!(arr[1.. ], [  1,2,3]);  // RangeFrom
    assert_eq!(arr[1..3], [  1,2  ]);
}

Fields

start: Idx

[−] Expand description

The lower bound of the range (inclusive).

Methods

impl<Idx> RangeFrom<Idx> where Idx: PartialOrd<Idx>

fn contains(&self, item: Idx) -> bool[−]

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

recently added as per RFC

Examples

#![feature(range_contains)]
fn main() {
    assert!( ! (3..).contains(2));
    assert!(   (3..).contains(3));
    assert!(   (3..).contains(1_000_000_000));
}

impl<A> RangeFrom<A> where A: Step

fn step_by(self, by: A) -> StepBy<A, RangeFrom<A>>[−]

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

recent addition

Creates an iterator starting at the same point, but stepping by the given amount at each iteration.

Examples

#![feature(step_by)]
fn main() {
    let result: Vec<_> = (0..).step_by(2).take(5).collect();
    assert_eq!(result, vec![0, 2, 4, 6, 8]);
}

Trait Implementations

impl<A> FusedIterator for RangeFrom<A> where A: Step,
        &'a A: Add<&'a A>,
        &'a A::Output == A

impl<Idx> Hash for RangeFrom<Idx> where Idx: Hash

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[−]

Feeds a slice of this type into the state provided.

impl<T> SliceIndex<T> for RangeFrom<usize>

type Output = [T]

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

The output type returned by methods.

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

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

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_get_slice)

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

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

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

Returns a shared reference 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_get_slice)

Returns a mutable reference 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_get_slice)

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_get_slice)

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

impl<Idx> PartialEq<RangeFrom<Idx>> for RangeFrom<Idx> where Idx: PartialEq<Idx>

fn eq(&self, __arg_0: &RangeFrom<Idx>) -> bool[−]

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

fn ne(&self, __arg_0: &RangeFrom<Idx>) -> bool[−]

This method tests for !=.

impl<Idx> Clone for RangeFrom<Idx> where Idx: Clone

fn clone(&self) -> RangeFrom<Idx>[−]

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)[−]

Performs copy-assignment from source.

impl<Idx> Eq for RangeFrom<Idx> where Idx: Eq

impl<A> Iterator for RangeFrom<A> where A: Step,
        &'a A: Add<&'a A>,
        &'a A::Output == A

type Item = A

The type of the elements being iterated over.

fn next(&mut self) -> Option<A>[−]

Advances the iterator and returns the next value.

fn size_hint(&self) -> (usize, Option<usize>)[−]

Returns the bounds on the remaining length of the iterator.

fn count(self) -> usize[−]

Consumes the iterator, counting the number of iterations and returning it.

fn last(self) -> Option<Self::Item>[−]

Consumes the iterator, returning the last element.

fn nth(&mut self, n: usize) -> Option<Self::Item>[−]

Returns the nth element of the iterator.

fn chain<U>(self, other: U) -> Chain<Self, U::IntoIter> where U: IntoIterator<Item=Self::Item>[−]

Takes two iterators and creates a new iterator over both in sequence.

fn zip<U>(self, other: U) -> Zip<Self, U::IntoIter> where U: IntoIterator[−]

'Zips up' two iterators into a single iterator of pairs.

fn map<B, F>(self, f: F) -> Map<Self, F> where F: FnMut(Self::Item) -> B[−]

Takes a closure and creates an iterator which calls that closure on each element.

fn filter<P>(self, predicate: P) -> Filter<Self, P> where P: FnMut(&Self::Item) -> bool[−]

Creates an iterator which uses a closure to determine if an element should be yielded.

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where F: FnMut(Self::Item) -> Option<B>[−]

Creates an iterator that both filters and maps.

fn enumerate(self) -> Enumerate<Self>[−]

Creates an iterator which gives the current iteration count as well as the next value.

fn peekable(self) -> Peekable<Self>[−]

Creates an iterator which can use peek to look at the next element of the iterator without consuming it.

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where P: FnMut(&Self::Item) -> bool[−]

Creates an iterator that [skip()]s elements based on a predicate.

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where P: FnMut(&Self::Item) -> bool[−]

Creates an iterator that yields elements based on a predicate.

fn skip(self, n: usize) -> Skip<Self>[−]

Creates an iterator that skips the first n elements.

fn take(self, n: usize) -> Take<Self>[−]

Creates an iterator that yields its first n elements.

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where F: FnMut(&mut St, Self::Item) -> Option<B>[−]

An iterator adaptor similar to [fold()] that holds internal state and produces a new iterator.

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where F: FnMut(Self::Item) -> U, U: IntoIterator[−]

Creates an iterator that works like map, but flattens nested structure.

fn fuse(self) -> Fuse<Self>[−]

Creates an iterator which ends after the first [None].

fn inspect<F>(self, f: F) -> Inspect<Self, F> where F: FnMut(&Self::Item) -> ()[−]

Do something with each element of an iterator, passing the value on.

fn by_ref(&mut self) -> &mut Self[−]

Borrows an iterator, rather than consuming it.

fn collect<B>(self) -> B where B: FromIterator<Self::Item>[−]

Transforms an iterator into a collection.

fn partition<B, F>(self, f: F) -> (B, B) where B: Default + Extend<Self::Item>, F: FnMut(&Self::Item) -> bool[−]

Consumes an iterator, creating two collections from it.

fn fold<B, F>(self, init: B, f: F) -> B where F: FnMut(B, Self::Item) -> B[−]

An iterator adaptor that applies a function, producing a single, final value.

fn all<F>(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool[−]

Tests if every element of the iterator matches a predicate.

fn any<F>(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool[−]

Tests if any element of the iterator matches a predicate.

fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where P: FnMut(&Self::Item) -> bool[−]

Searches for an element of an iterator that satisfies a predicate.

fn position<P>(&mut self, predicate: P) -> Option<usize> where P: FnMut(Self::Item) -> bool[−]

Searches for an element in an iterator, returning its index.

fn rposition<P>(&mut self, predicate: P) -> Option<usize> where P: FnMut(Self::Item) -> bool,
        Self: ExactSizeIterator + DoubleEndedIterator[−]

Searches for an element in an iterator from the right, returning its index.

fn max(self) -> Option<Self::Item> where Self::Item: Ord[−]

Returns the maximum element of an iterator.

fn min(self) -> Option<Self::Item> where Self::Item: Ord[−]

Returns the minimum element of an iterator.

fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where B: Ord, F: FnMut(&Self::Item) -> B[−]

Returns the element that gives the maximum value from the specified function.

fn max_by<F>(self, compare: F) -> Option<Self::Item> where F: FnMut(&Self::Item, &Self::Item) -> Ordering[−]

Returns the element that gives the maximum value with respect to the specified comparison function.

fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where B: Ord, F: FnMut(&Self::Item) -> B[−]

Returns the element that gives the minimum value from the specified function.

fn min_by<F>(self, compare: F) -> Option<Self::Item> where F: FnMut(&Self::Item, &Self::Item) -> Ordering[−]

Returns the element that gives the minimum value with respect to the specified comparison function.

fn rev(self) -> Rev<Self> where Self: DoubleEndedIterator[−]

Reverses an iterator's direction.

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where FromA: Default + Extend<A>,
        FromB: Default + Extend<B>,
        Self: Iterator<Item=(A, B)>[−]

Converts an iterator of pairs into a pair of containers.

fn cloned<'a, T>(self) -> Cloned<Self> where Self: Iterator<Item=&'a T>, T: 'a + Clone[−]

Creates an iterator which [clone()]s all of its elements.

fn cycle(self) -> Cycle<Self> where Self: Clone[−]

Repeats an iterator endlessly.

fn sum<S>(self) -> S where S: Sum<Self::Item>[−]

Sums the elements of an iterator.

fn product<P>(self) -> P where P: Product<Self::Item>[−]

Iterates over the entire iterator, multiplying all the elements

fn cmp<I>(self, other: I) -> Ordering where I: IntoIterator<Item=Self::Item>, Self::Item: Ord[−]

Lexicographically compares the elements of this Iterator with those of another.

fn partial_cmp<I>(self, other: I) -> Option<Ordering> where I: IntoIterator, Self::Item: PartialOrd<I::Item>[−]

Lexicographically compares the elements of this Iterator with those of another.

fn eq<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialEq<I::Item>[−]

Determines if the elements of this Iterator are equal to those of another.

fn ne<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialEq<I::Item>[−]

Determines if the elements of this Iterator are unequal to those of another.

fn lt<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>[−]

Determines if the elements of this Iterator are lexicographically less than those of another.

fn le<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>[−]

Determines if the elements of this Iterator are lexicographically less or equal to those of another.

fn gt<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>[−]

Determines if the elements of this Iterator are lexicographically greater than those of another.

fn ge<I>(self, other: I) -> bool where I: IntoIterator, Self::Item: PartialOrd<I::Item>[−]

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another.

impl<Idx> Debug for RangeFrom<Idx> where Idx: Debug

fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>[−]

Formats the value using the given formatter.

impl<T> RangeArgument<T> for RangeFrom<T>

fn start(&self) -> Bound<&T>[−]

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

waiting for dust to settle on inclusive ranges

Start index bound

fn end(&self) -> Bound<&T>[−]

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

waiting for dust to settle on inclusive ranges

End index bound