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.


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 {
    // ...

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    ]);  // 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  ]);Run


end: Idx

The upper bound of the range (exclusive).


impl<Idx> RangeTo<Idx> where
    Idx: PartialOrd<Idx>, 

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.


use std::f32;

assert!( (..5).contains(&-1_000_000_000));
assert!( (..5).contains(&4));

assert!( (..1.0).contains(&0.5));

Trait Implementations

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

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

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

impl SliceIndex<str> for RangeTo<usize>1.20.0[src]

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 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.

impl<T> SliceIndex<[T]> for RangeTo<usize>1.15.0[src]

type Output = [T]

The output type returned by methods.

impl<T> RangeBounds<T> for RangeTo<T>1.28.0[src]

impl<'_, T> RangeBounds<T> for RangeTo<&'_ T>1.28.0[src]

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

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

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

impl IndexMut<RangeTo<usize>> for String1.3.0[src]

impl Index<RangeTo<usize>> for String[src]

type Output = str

The returned type after indexing.

Auto Trait Implementations

impl<Idx> UnwindSafe for RangeTo<Idx> where
    Idx: UnwindSafe

impl<Idx> RefUnwindSafe for RangeTo<Idx> where
    Idx: RefUnwindSafe

impl<Idx> Unpin for RangeTo<Idx> where
    Idx: Unpin

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

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

Blanket Implementations

impl<T> From<T> for T[src]

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 

type Error = Infallible

The type returned in the event of a conversion error.

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

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

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

The type returned in the event of a conversion error.

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

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

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

impl<T> ToOwned for T where
    T: Clone

type Owned = T

The resulting type after obtaining ownership.