Struct core::range::RangeFrom

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

🔬This is a nightly-only experimental API. (new_range_api #125687)

A range only bounded inclusively below (start..).

The RangeFrom start.. contains all values with x >= start.

Note: Overflow in the Iterator implementation (when the contained data type reaches its numerical limit) is allowed to panic, wrap, or saturate. This behavior is defined by the implementation of the Step trait. For primitive integers, this follows the normal rules, and respects the overflow checks profile (panic in debug, wrap in release). Note also that overflow happens earlier than you might assume: the overflow happens in the call to next that yields the maximum value, as the range must be set to a state to yield the next value.

Examples

The start.. syntax is a RangeFrom:

#![feature(new_range_api)]
use core::range::RangeFrom;

assert_eq!(RangeFrom::from(2..), core::range::RangeFrom { start: 2 });
assert_eq!(2 + 3 + 4, RangeFrom::from(2..).into_iter().take(3).sum());

Fields

start: Idx

🔬This is a nightly-only experimental API. (new_range_api #125687)

The lower bound of the range (inclusive).

Implementations

impl<Idx: Step> RangeFrom<Idx>

pub fn iter(&self) -> IterRangeFrom<Idx>

🔬This is a nightly-only experimental API. (new_range_api #125687)

Create an iterator over the elements within this range.

Shorthand for .clone().into_iter()

Examples

#![feature(new_range_api)]
use core::range::RangeFrom;

let mut i = RangeFrom::from(3..).iter().map(|n| n*n);
assert_eq!(i.next(), Some(9));
assert_eq!(i.next(), Some(16));
assert_eq!(i.next(), Some(25));

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

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

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

🔬This is a nightly-only experimental API. (new_range_api #125687)

Returns true if item is contained in the range.

Examples

#![feature(new_range_api)]
use core::range::RangeFrom;

assert!(!RangeFrom::from(3..).contains(&2));
assert!( RangeFrom::from(3..).contains(&3));
assert!( RangeFrom::from(3..).contains(&1_000_000_000));

assert!( RangeFrom::from(0.0..).contains(&0.5));
assert!(!RangeFrom::from(0.0..).contains(&f32::NAN));
assert!(!RangeFrom::from(f32::NAN..).contains(&0.5));

Trait Implementations

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

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: Debug> Debug for RangeFrom<Idx>

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

Formats the value using the given formatter.

impl<T> From<RangeFrom<T>> for RangeFrom<T>

fn from(value: RangeFrom<T>) -> Self

Converts to this type from the input type.

impl<T> From<RangeFrom<T>> for RangeFrom<T>

fn from(value: RangeFrom<T>) -> Self

Converts to this type from the input type.

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

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

Feeds this value into the given Hasher.

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

where Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<A: Step> IntoIterator for RangeFrom<A>

type Item = A

The type of the elements being iterated over.

type IntoIter = IterRangeFrom<A>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

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

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

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

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

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

impl<T> RangeBounds<T> for RangeFrom<&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: ?Sized + PartialOrd<T>,

Returns true if item is contained in the range.

impl<T> RangeBounds<T> for RangeFrom<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: ?Sized + PartialOrd<T>,

Returns true if item is contained in the range.

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

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. Calling this method with an out-of-bounds index or a dangling slice pointer is undefined behavior even if the resulting pointer is not used.

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. Calling this method with an out-of-bounds index or a dangling slice pointer is undefined behavior even if the resulting pointer is not used.

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 RangeFrom<usize>

type Output = str

The output type returned by methods.

fn get(self, slice: &str) -> Option<&Self::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 Self::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 Self::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. Calling this method with an out-of-bounds index or a dangling slice pointer is undefined behavior even if the resulting pointer is not used.

unsafe fn get_unchecked_mut(self, slice: *mut str) -> *mut Self::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. Calling this method with an out-of-bounds index or a dangling slice pointer is undefined behavior even if the resulting pointer is not used.

fn index(self, slice: &str) -> &Self::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 Self::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> Copy for RangeFrom<Idx>

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

impl<Idx> StructuralPartialEq for RangeFrom<Idx>