Module std::slice

A dynamically-sized view into a contiguous sequence, [T].

See also the slice primitive type.

Slices are a view into a block of memory represented as a pointer and a length.

// slicing a Vec
let vec = vec![1, 2, 3];
let int_slice = &vec[..];
// coercing an array to a slice
let str_slice: &[&str] = &["one", "two", "three"];

Slices are either mutable or shared. The shared slice type is &[T], while the mutable slice type is &mut [T], where T represents the element type. For example, you can mutate the block of memory that a mutable slice points to:

let x = &mut [1, 2, 3];
x[1] = 7;
assert_eq!(x, &[1, 7, 3]);

Here are some of the things this module contains:

Structs

There are several structs that are useful for slices, such as Iter, which represents iteration over a slice.

Trait Implementations

There are several implementations of common traits for slices. Some examples include:

• Clone
• Eq, Ord - for slices whose element type are Eq or Ord.
• Hash - for slices whose element type is Hash.

Iteration

The slices implement IntoIterator. The iterator yields references to the slice elements.

let numbers = &[0, 1, 2];
for n in numbers {
    println!("{} is a number!", n);
}

The mutable slice yields mutable references to the elements:

let mut scores = [7, 8, 9];
for score in &mut scores[..] {
    *score += 1;
}

This iterator yields mutable references to the slice's elements, so while the element type of the slice is i32, the element type of the iterator is &mut i32.

• .iter and .iter_mut are the explicit methods to return the default iterators.
• Further methods that return iterators are .split, .splitn, .chunks, .windows and more.

Structs

Chunks	An iterator over a slice in (non-overlapping) chunks (chunk_size elements at a time).
ChunksMut	An iterator over a slice in (non-overlapping) mutable chunks (chunk_size elements at a time). When the slice len is not evenly divided by the chunk size, the last slice of the iteration will be the remainder.
Iter	Immutable slice iterator
IterMut	Mutable slice iterator.
RSplit	An iterator over subslices separated by elements that match a predicate function, starting from the end of the slice.
RSplitMut	An iterator over the subslices of the vector which are separated by elements that match pred, starting from the end of the slice.
RSplitN	An iterator over subslices separated by elements that match a predicate function, limited to a given number of splits, starting from the end of the slice.
RSplitNMut	An iterator over subslices separated by elements that match a predicate function, limited to a given number of splits, starting from the end of the slice.
Split	An iterator over subslices separated by elements that match a predicate function.
SplitMut	An iterator over the subslices of the vector which are separated by elements that match pred.
SplitN	An iterator over subslices separated by elements that match a predicate function, limited to a given number of splits.
SplitNMut	An iterator over subslices separated by elements that match a predicate function, limited to a given number of splits.
Windows	An iterator over overlapping subslices of length size.
ExactChunks	[ Experimental ] An iterator over a slice in (non-overlapping) chunks (chunk_size elements at a time).
ExactChunksMut	[ Experimental ] An iterator over a slice in (non-overlapping) mutable chunks (chunk_size elements at a time). When the slice len is not evenly divided by the chunk size, the last up to chunk_size-1 elements will be omitted.

Traits

SliceConcatExt	[ Experimental ] An extension trait for concatenating slices
SliceIndex	[ Experimental ] A helper trait used for indexing operations.

Functions

from_mut	Converts a reference to T into a slice of length 1 (without copying).
from_raw_parts⚠	Forms a slice from a pointer and a length.
from_raw_parts_mut⚠	Performs the same functionality as from_raw_parts, except that a mutable slice is returned.
from_ref	Converts a reference to T into a slice of length 1 (without copying).