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.

Examples

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 {
    // ...
}Run

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

Fields

end: Idx

The upper bound of the range (exclusive).

Methods

impl<Idx> RangeTo<Idx> where
    Idx: PartialOrd<Idx>, 
[src]

pub fn contains<U>(&self, item: &U) -> bool where
    Idx: PartialOrd<U>,
    U: PartialOrd<Idx> + ?Sized
1.35.0[src]

Returns true if item is contained in the range.

Examples

use std::f32;

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));Run

Trait Implementations

impl<Idx> Eq for RangeTo<Idx> where
    Idx: Eq
[src]

impl<Idx> PartialEq<RangeTo<Idx>> for RangeTo<Idx> where
    Idx: PartialEq<Idx>, 
[src]

impl<Idx> StructuralEq for RangeTo<Idx>[src]

impl<Idx> Hash for RangeTo<Idx> where
    Idx: Hash
[src]

impl<Idx> Clone for RangeTo<Idx> where
    Idx: Clone
[src]

impl<Idx> StructuralPartialEq for RangeTo<Idx>[src]

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

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

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

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<Idx> Copy for RangeTo<Idx> where
    Idx: Copy
[src]

impl<Idx> Debug for RangeTo<Idx> where
    Idx: Debug
[src]

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

type Output = str

The returned type after indexing.

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

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>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

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
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

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

impl<T> ToOwned for T where
    T: Clone
[src]

type Owned = T

The resulting type after obtaining ownership.