1.28.0[−][src]Trait alloc::slice::SliceIndex

pub trait SliceIndex<T>: Sealed where
    T: ?Sized, {
    type Output: ?Sized;
    fn get(self, slice: &T) -> Option<&Self::Output>;

    fn get_mut(self, slice: &mut T) -> Option<&mut Self::Output>;

    unsafe fn get_unchecked(self, slice: &T) -> &Self::Output;

    unsafe fn get_unchecked_mut(self, slice: &mut T) -> &mut Self::Output;

    fn index(self, slice: &T) -> &Self::Output;

    fn index_mut(self, slice: &mut T) -> &mut Self::Output;
}

A helper trait used for indexing operations.

Associated Types

type Output: ?Sized

The output type returned by methods.

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Required methods

fn get(self, slice: &T) -> Option<&Self::Output>

🔬 This is a nightly-only experimental API. (slice_index_methods #0)

Returns a shared reference to the output at this location, if in bounds.

fn get_mut(self, slice: &mut T) -> Option<&mut Self::Output>

🔬 This is a nightly-only experimental API. (slice_index_methods #0)

Returns a mutable reference to the output at this location, if in bounds.

unsafe fn get_unchecked(self, slice: &T) -> &Self::Output

🔬 This is a nightly-only experimental API. (slice_index_methods #0)

Returns a shared reference to the output at this location, without performing any bounds checking. Calling this method with an out-of-bounds index is [undefined behavior] even if the resulting reference is not used. [undefined behavior]: ../../reference/behavior-considered-undefined.html

unsafe fn get_unchecked_mut(self, slice: &mut T) -> &mut Self::Output

🔬 This is a nightly-only experimental API. (slice_index_methods #0)

Returns a mutable reference to the output at this location, without performing any bounds checking. Calling this method with an out-of-bounds index is [undefined behavior] even if the resulting reference is not used. [undefined behavior]: ../../reference/behavior-considered-undefined.html

fn index(self, slice: &T) -> &Self::Output

🔬 This is a nightly-only experimental API. (slice_index_methods #0)

Returns a shared reference to the output at this location, panicking if out of bounds.

fn index_mut(self, slice: &mut T) -> &mut Self::Output

🔬 This is a nightly-only experimental API. (slice_index_methods #0)

Returns a mutable reference to the output at this location, panicking if out of bounds.

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Implementations on Foreign Types

impl<T> SliceIndex<[T]> for Range<usize>[src]

type Output = [T]

impl SliceIndex<str> for Range<usize>[src]

Implements substring slicing with syntax &self[begin .. end] or &mut self[begin .. end].

Returns a slice of the given string from the byte range [begin, 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 begin or end does not point to the starting byte offset of a character (as defined by is_char_boundary), if begin > end, or if end > len.

Examples

let s = "Löwe 老虎 Léopard";
assert_eq!(&s[0 .. 1], "L");

assert_eq!(&s[1 .. 9], "öwe 老");

// these will panic:
// byte 2 lies within `ö`:
// &s[2 ..3];

// byte 8 lies within `老`
// &s[1 .. 8];

// byte 100 is outside the string
// &s[3 .. 100];

type Output = str

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

type Output = [T]

impl SliceIndex<str> for RangeTo<usize>[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

impl<T> SliceIndex<[T]> for RangeInclusive<usize>[src]

type Output = [T]

impl<T> SliceIndex<[T]> for RangeToInclusive<usize>[src]

type Output = [T]

impl SliceIndex<str> for RangeInclusive<usize>[src]

Implements substring slicing with syntax &self[begin ..= end] or &mut self[begin ..= end].

Returns a slice of the given string from the byte range [begin, end]. Equivalent to &self [begin .. end + 1] or &mut self[begin .. end + 1], except if end has the maximum value for usize.

This operation is O(1).

Panics

Panics if begin does not point to the starting byte offset of a character (as defined by is_char_boundary), if end does not point to the ending byte offset of a character (end + 1 is either a starting byte offset or equal to len), if begin > end, or if end >= len.

type Output = str

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

type Output = [T]

impl SliceIndex<str> for RangeFrom<usize>[src]

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.

type Output = str

impl<T> SliceIndex<[T]> for RangeFull[src]

type Output = [T]

impl SliceIndex<str> for RangeFull[src]

Implements substring slicing with syntax &self[..] or &mut self[..].

Returns a slice of the whole string, i.e., returns &self or &mut self. Equivalent to &self[0 .. len] or &mut self[0 .. len]. Unlike other indexing operations, this can never panic.

This operation is O(1).

Prior to 1.20.0, these indexing operations were still supported by direct implementation of Index and IndexMut.

Equivalent to &self[0 .. len] or &mut self[0 .. len].

type Output = str

impl SliceIndex<str> for RangeToInclusive<usize>[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 + 1], except if end has the maximum value for usize.

This operation is O(1).

Panics

Panics if end does not point to the ending byte offset of a character (end + 1 is either a starting byte offset as defined by is_char_boundary, or equal to len), or if end >= len.

type Output = str

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Implementors

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

type Output = T

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