pub struct RangeFrom<Idx> {
pub start: Idx,
}
Expand description
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
:
assert_eq!((2..), std::ops::RangeFrom { start: 2 });
assert_eq!(2 + 3 + 4, (2..).take(3).sum());
Runlet arr = [0, 1, 2, 3, 4];
assert_eq!(arr[ .. ], [0, 1, 2, 3, 4]);
assert_eq!(arr[ .. 3], [0, 1, 2 ]);
assert_eq!(arr[ ..=3], [0, 1, 2, 3 ]);
assert_eq!(arr[1.. ], [ 1, 2, 3, 4]); // This is a `RangeFrom`
assert_eq!(arr[1.. 3], [ 1, 2 ]);
assert_eq!(arr[1..=3], [ 1, 2, 3 ]);
RunFields§
§start: Idx
The lower bound of the range (inclusive).
Implementations§
Trait Implementations§
1.0.0 · source§impl<A: Step> Iterator for RangeFrom<A>
impl<A: Step> Iterator for RangeFrom<A>
source§fn size_hint(&self) -> (usize, Option<usize>)
fn size_hint(&self) -> (usize, Option<usize>)
source§fn next_chunk<const N: usize>(
&mut self,
) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>where
Self: Sized,
fn next_chunk<const N: usize>(
&mut self,
) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>where
Self: Sized,
iter_next_chunk
#98326)N
values. Read more1.0.0 · source§fn count(self) -> usizewhere
Self: Sized,
fn count(self) -> usizewhere
Self: Sized,
1.0.0 · source§fn last(self) -> Option<Self::Item>where
Self: Sized,
fn last(self) -> Option<Self::Item>where
Self: Sized,
source§fn advance_by(&mut self, n: usize) -> Result<(), NonZero<usize>>
fn advance_by(&mut self, n: usize) -> Result<(), NonZero<usize>>
iter_advance_by
#77404)n
elements. Read more1.28.0 · source§fn step_by(self, step: usize) -> StepBy<Self> ⓘwhere
Self: Sized,
fn step_by(self, step: usize) -> StepBy<Self> ⓘwhere
Self: Sized,
1.0.0 · source§fn chain<U>(self, other: U) -> Chain<Self, U::IntoIter> ⓘ
fn chain<U>(self, other: U) -> Chain<Self, U::IntoIter> ⓘ
1.0.0 · source§fn zip<U>(self, other: U) -> Zip<Self, U::IntoIter> ⓘwhere
Self: Sized,
U: IntoIterator,
fn zip<U>(self, other: U) -> Zip<Self, U::IntoIter> ⓘwhere
Self: Sized,
U: IntoIterator,
source§fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G> ⓘ
fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G> ⓘ
iter_intersperse
#79524)separator
between adjacent items of the original iterator. Read more1.0.0 · source§fn map<B, F>(self, f: F) -> Map<Self, F> ⓘ
fn map<B, F>(self, f: F) -> Map<Self, F> ⓘ
1.0.0 · source§fn filter<P>(self, predicate: P) -> Filter<Self, P> ⓘ
fn filter<P>(self, predicate: P) -> Filter<Self, P> ⓘ
1.0.0 · source§fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> ⓘ
fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> ⓘ
1.0.0 · source§fn enumerate(self) -> Enumerate<Self> ⓘwhere
Self: Sized,
fn enumerate(self) -> Enumerate<Self> ⓘwhere
Self: Sized,
1.0.0 · source§fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> ⓘ
fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> ⓘ
1.0.0 · source§fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> ⓘ
fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> ⓘ
1.57.0 · source§fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P> ⓘ
fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P> ⓘ
1.0.0 · source§fn skip(self, n: usize) -> Skip<Self> ⓘwhere
Self: Sized,
fn skip(self, n: usize) -> Skip<Self> ⓘwhere
Self: Sized,
n
elements. Read more1.0.0 · source§fn take(self, n: usize) -> Take<Self> ⓘwhere
Self: Sized,
fn take(self, n: usize) -> Take<Self> ⓘwhere
Self: Sized,
n
elements, or fewer
if the underlying iterator ends sooner. Read more1.0.0 · source§fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> ⓘ
fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> ⓘ
source§fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N> ⓘ
fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N> ⓘ
iter_map_windows
#87155)f
for each contiguous window of size N
over
self
and returns an iterator over the outputs of f
. Like slice::windows()
,
the windows during mapping overlap as well. Read more1.0.0 · source§fn inspect<F>(self, f: F) -> Inspect<Self, F> ⓘ
fn inspect<F>(self, f: F) -> Inspect<Self, F> ⓘ
1.0.0 · source§fn by_ref(&mut self) -> &mut Selfwhere
Self: Sized,
fn by_ref(&mut self) -> &mut Selfwhere
Self: Sized,
1.0.0 · source§fn collect<B: FromIterator<Self::Item>>(self) -> Bwhere
Self: Sized,
fn collect<B: FromIterator<Self::Item>>(self) -> Bwhere
Self: Sized,
source§fn collect_into<E: Extend<Self::Item>>(self, collection: &mut E) -> &mut Ewhere
Self: Sized,
fn collect_into<E: Extend<Self::Item>>(self, collection: &mut E) -> &mut Ewhere
Self: Sized,
iter_collect_into
#94780)1.0.0 · source§fn partition<B, F>(self, f: F) -> (B, B)
fn partition<B, F>(self, f: F) -> (B, B)
source§fn is_partitioned<P>(self, predicate: P) -> bool
fn is_partitioned<P>(self, predicate: P) -> bool
iter_is_partitioned
#62544)true
precede all those that return false
. Read more1.27.0 · source§fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
1.27.0 · source§fn try_for_each<F, R>(&mut self, f: F) -> R
fn try_for_each<F, R>(&mut self, f: F) -> R
1.0.0 · source§fn fold<B, F>(self, init: B, f: F) -> B
fn fold<B, F>(self, init: B, f: F) -> B
1.51.0 · source§fn reduce<F>(self, f: F) -> Option<Self::Item>
fn reduce<F>(self, f: F) -> Option<Self::Item>
source§fn try_reduce<R>(
&mut self,
f: impl FnMut(Self::Item, Self::Item) -> R,
) -> <R::Residual as Residual<Option<R::Output>>>::TryType
fn try_reduce<R>( &mut self, f: impl FnMut(Self::Item, Self::Item) -> R, ) -> <R::Residual as Residual<Option<R::Output>>>::TryType
iterator_try_reduce
#87053)1.0.0 · source§fn all<F>(&mut self, f: F) -> bool
fn all<F>(&mut self, f: F) -> bool
1.0.0 · source§fn any<F>(&mut self, f: F) -> bool
fn any<F>(&mut self, f: F) -> bool
1.0.0 · source§fn find<P>(&mut self, predicate: P) -> Option<Self::Item>
fn find<P>(&mut self, predicate: P) -> Option<Self::Item>
1.30.0 · source§fn find_map<B, F>(&mut self, f: F) -> Option<B>
fn find_map<B, F>(&mut self, f: F) -> Option<B>
source§fn try_find<R>(
&mut self,
f: impl FnMut(&Self::Item) -> R,
) -> <R::Residual as Residual<Option<Self::Item>>>::TryType
fn try_find<R>( &mut self, f: impl FnMut(&Self::Item) -> R, ) -> <R::Residual as Residual<Option<Self::Item>>>::TryType
try_find
#63178)1.0.0 · source§fn position<P>(&mut self, predicate: P) -> Option<usize>
fn position<P>(&mut self, predicate: P) -> Option<usize>
1.6.0 · source§fn max_by_key<B: Ord, F>(self, f: F) -> Option<Self::Item>
fn max_by_key<B: Ord, F>(self, f: F) -> Option<Self::Item>
1.15.0 · source§fn max_by<F>(self, compare: F) -> Option<Self::Item>
fn max_by<F>(self, compare: F) -> Option<Self::Item>
1.6.0 · source§fn min_by_key<B: Ord, F>(self, f: F) -> Option<Self::Item>
fn min_by_key<B: Ord, F>(self, f: F) -> Option<Self::Item>
1.15.0 · source§fn min_by<F>(self, compare: F) -> Option<Self::Item>
fn min_by<F>(self, compare: F) -> Option<Self::Item>
1.0.0 · source§fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)
fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)
1.36.0 · source§fn copied<'a, T>(self) -> Copied<Self> ⓘ
fn copied<'a, T>(self) -> Copied<Self> ⓘ
source§fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N> ⓘwhere
Self: Sized,
fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N> ⓘwhere
Self: Sized,
iter_array_chunks
#100450)N
elements of the iterator at a time. Read more1.11.0 · source§fn product<P>(self) -> P
fn product<P>(self) -> P
source§fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering
fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering
iter_order_by
#64295)Iterator
with those
of another with respect to the specified comparison function. Read more1.5.0 · source§fn partial_cmp<I>(self, other: I) -> Option<Ordering>
fn partial_cmp<I>(self, other: I) -> Option<Ordering>
PartialOrd
elements of
this Iterator
with those of another. The comparison works like short-circuit
evaluation, returning a result without comparing the remaining elements.
As soon as an order can be determined, the evaluation stops and a result is returned. Read moresource§fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>
fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>
iter_order_by
#64295)Iterator
with those
of another with respect to the specified comparison function. Read moresource§fn eq_by<I, F>(self, other: I, eq: F) -> bool
fn eq_by<I, F>(self, other: I, eq: F) -> bool
iter_order_by
#64295)1.5.0 · source§fn lt<I>(self, other: I) -> bool
fn lt<I>(self, other: I) -> bool
Iterator
are lexicographically
less than those of another. Read more1.5.0 · source§fn le<I>(self, other: I) -> bool
fn le<I>(self, other: I) -> bool
Iterator
are lexicographically
less or equal to those of another. Read more1.5.0 · source§fn gt<I>(self, other: I) -> bool
fn gt<I>(self, other: I) -> bool
Iterator
are lexicographically
greater than those of another. Read more1.5.0 · source§fn ge<I>(self, other: I) -> bool
fn ge<I>(self, other: I) -> bool
Iterator
are lexicographically
greater than or equal to those of another. Read moresource§fn is_sorted_by<F>(self, compare: F) -> bool
fn is_sorted_by<F>(self, compare: F) -> bool
is_sorted
#53485)1.0.0 · source§impl<Idx: PartialEq> PartialEq for RangeFrom<Idx>
impl<Idx: PartialEq> PartialEq for RangeFrom<Idx>
1.28.0 · source§impl<T> RangeBounds<T> for RangeFrom<&T>
impl<T> RangeBounds<T> for RangeFrom<&T>
1.28.0 · source§impl<T> RangeBounds<T> for RangeFrom<T>
impl<T> RangeBounds<T> for RangeFrom<T>
1.15.0 (const: unstable) · source§impl<T> SliceIndex<[T]> for RangeFrom<usize>
impl<T> SliceIndex<[T]> for RangeFrom<usize>
The methods index
and index_mut
panic if the start of the range is out of bounds.
source§fn get(self, slice: &[T]) -> Option<&[T]>
fn get(self, slice: &[T]) -> Option<&[T]>
slice_index_methods
)source§fn get_mut(self, slice: &mut [T]) -> Option<&mut [T]>
fn get_mut(self, slice: &mut [T]) -> Option<&mut [T]>
slice_index_methods
)source§unsafe fn get_unchecked(self, slice: *const [T]) -> *const [T]
unsafe fn get_unchecked(self, slice: *const [T]) -> *const [T]
slice_index_methods
)slice
pointer
is undefined behavior even if the resulting pointer is not used.source§unsafe fn get_unchecked_mut(self, slice: *mut [T]) -> *mut [T]
unsafe fn get_unchecked_mut(self, slice: *mut [T]) -> *mut [T]
slice_index_methods
)slice
pointer
is undefined behavior even if the resulting pointer is not used.1.20.0 (const: unstable) · source§impl SliceIndex<str> for RangeFrom<usize>
impl SliceIndex<str> for RangeFrom<usize>
Implements substring slicing with syntax &self[begin ..]
or &mut self[begin ..]
.
Returns a slice of the given string from the byte range [begin
, len
).
Equivalent to &self[begin .. len]
or &mut self[begin .. len]
.
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 begin
does not point to the starting byte offset of
a character (as defined by is_char_boundary
), or if begin > len
.
source§fn get(self, slice: &str) -> Option<&Self::Output>
fn get(self, slice: &str) -> Option<&Self::Output>
slice_index_methods
)source§fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output>
fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output>
slice_index_methods
)source§unsafe fn get_unchecked(self, slice: *const str) -> *const Self::Output
unsafe fn get_unchecked(self, slice: *const str) -> *const Self::Output
slice_index_methods
)slice
pointer
is undefined behavior even if the resulting pointer is not used.source§unsafe fn get_unchecked_mut(self, slice: *mut str) -> *mut Self::Output
unsafe fn get_unchecked_mut(self, slice: *mut str) -> *mut Self::Output
slice_index_methods
)slice
pointer
is undefined behavior even if the resulting pointer is not used.