1.0.0[][src]Struct core::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: PartialOrd<Idx>> RangeTo<Idx>[src]

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

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

impl<Idx: Copy> Copy 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<Idx: PartialEq> PartialEq<RangeTo<Idx>> for RangeTo<Idx>[src]

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

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

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

type Output = [T]

The output type returned by methods.

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

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

Auto Trait Implementations

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

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

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

Blanket Implementations

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

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

type 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]