as_slice/
lib.rs

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1//! `AsSlice` and `AsMutSlice` traits
2//!
3//! These traits are somewhat similar to the `AsRef` and `AsMut` except that they are **NOT**
4//! polymorphic (no input type parameter) and their methods always return slices (`[T]`).
5//!
6//! The main use case of these traits is writing generic code that accepts (fixed size) buffers. For
7//! example, a bound `T: StableDeref + AsMutSlice<Element = u8> + 'static` will accepts types like
8//! `&'static mut [u8]` and `&'static mut [u8; 128]` -- all
9//! of them are appropriate for DMA transfers.
10//!
11//! # Minimal Supported Rust Version (MSRV)
12//!
13//! This crate is guaranteed to compile on stable Rust 1.51 and up. It *might* compile on older
14//! versions but that may change in any new patch release.
15
16#![deny(missing_docs)]
17#![deny(warnings)]
18#![no_std]
19
20extern crate stable_deref_trait;
21
22/// Something that can be seen as an immutable slice
23pub trait AsSlice {
24    /// The element type of the slice view
25    type Element;
26
27    /// Returns the immutable slice view of `Self`
28    fn as_slice(&self) -> &[Self::Element];
29}
30
31/// Something that can be seen as an mutable slice
32pub trait AsMutSlice: AsSlice {
33    /// Returns the mutable slice view of `Self`
34    fn as_mut_slice(&mut self) -> &mut [Self::Element];
35}
36
37impl<'a, S> AsSlice for &'a S
38where
39    S: ?Sized + AsSlice,
40{
41    type Element = S::Element;
42
43    fn as_slice(&self) -> &[S::Element] {
44        (**self).as_slice()
45    }
46}
47
48impl<'a, S> AsSlice for &'a mut S
49where
50    S: ?Sized + AsSlice,
51{
52    type Element = S::Element;
53
54    fn as_slice(&self) -> &[S::Element] {
55        (**self).as_slice()
56    }
57}
58
59impl<'a, S> AsMutSlice for &'a mut S
60where
61    S: ?Sized + AsMutSlice,
62{
63    fn as_mut_slice(&mut self) -> &mut [S::Element] {
64        (**self).as_mut_slice()
65    }
66}
67
68impl<T> AsSlice for [T] {
69    type Element = T;
70
71    fn as_slice(&self) -> &[T] {
72        self
73    }
74}
75
76impl<T> AsMutSlice for [T] {
77    fn as_mut_slice(&mut self) -> &mut [T] {
78        self
79    }
80}
81
82impl<T, const N: usize> AsSlice for [T; N] {
83    type Element = T;
84
85    fn as_slice(&self) -> &[T] {
86        self
87    }
88}
89
90impl<T, const N: usize> AsMutSlice for [T; N] {
91    fn as_mut_slice(&mut self) -> &mut [T] {
92        self
93    }
94}
as_slice/lib.rs

as_slice/
lib.rs
