Struct abi_stable::std_types::RSlice

#[repr(C)]pub struct RSlice<'a, T> { /* fields omitted */ }

Ffi-safe equivalent of &'a [T]

As of the writing this documentation the abi stability of &[T] is not yet guaranteed.

Lifetime problems

Because RSlice dereferences into a slice,you can call slice methods on it.

If you call a slice method that returns a borrow into the slice, it will have the lifetime of the let slice: RSlice<'a,[T]> variable instead of the 'a lifetime that it's parameterized over.

To get a slice with the same lifetime as an RSlice, one must use the RSlice::as_slice method.

Example of what would not work:

use abi_stable::std_types::RSlice;

fn into_slice<'a,T>(slic:RSlice<'a,T>)->&'a [T] {
    &*slic
}

Example of what would work:

use abi_stable::std_types::RSlice;

fn into_slice<'a,T>(slic:RSlice<'a,T>)->&'a [T] {
    slic.as_slice()
}

Example

Defining an extern fn that returns a reference to the first element that compares equal to a parameter.

use abi_stable::{
    std_types::RSlice,
    sabi_extern_fn,
};

#[sabi_extern_fn]
pub fn find_first_mut<'a,T>(slice_:RSlice<'a,T>,element:&T)->Option<&'a T>
where
    T:std::cmp::PartialEq
{
    slice_.iter()
        .position(|x| x==element )
        .map(|i| &slice_.as_slice()[i] )
}

Implementations

impl<'a, T: 'a> RSlice<'a, T>

pub const EMPTY: Self

An empty slice.

pub const unsafe fn from_raw_parts(ptr_: *const T, len: usize) -> Self

Constructs an RSlice<'a,T> from a pointer to the first element, and a length.

Safety

Callers must ensure that:

• ptr_ points to valid memory,

• ptr_ .. ptr+len range is accessible memory.

• ptr_ is aligned to T.

• The data ptr_ points to must be valid for the 'a lifetime.

Examples

This function unsafely converts a &[T] to an RSlice<T>, equivalent to doing RSlice::from_slice.

use abi_stable::std_types::RSlice;

fn convert<T>(slice_:&[T])->RSlice<'_,T>{
    unsafe{
        RSlice::from_raw_parts( slice_.as_ptr(), slice_.len() )
    }
}

impl<'a, T> RSlice<'a, T>

pub fn as_slice(&self) -> &'a [T]

Creates an &'a [T] with access to all the elements of this slice.

Example

use abi_stable::std_types::RSlice;

assert_eq!(RSlice::from_slice(&[0,1,2,3]).as_slice(), &[0,1,2,3]);

pub const fn as_ptr(&self) -> *const T

Gets a raw pointer to the start of the slice.

pub const fn len(&self) -> usize

The length (in elements) of this slice.

Example

use abi_stable::std_types::RSlice;

assert_eq!(RSlice::<u8>::from_slice(&[]).len(), 0);
assert_eq!(RSlice::from_slice(&[0]).len(), 1);
assert_eq!(RSlice::from_slice(&[0,1]).len(), 2);

pub const fn is_empty(&self) -> bool

Whether this slice is empty.

Example

use abi_stable::std_types::RSlice;

assert_eq!(RSlice::<u8>::from_slice(&[]).is_empty(), true);
assert_eq!(RSlice::from_slice(&[0]).is_empty(), false);
assert_eq!(RSlice::from_slice(&[0,1]).is_empty(), false);

impl<'a, T> RSlice<'a, T>

pub const fn empty() -> Self

Creates an empty slice

pub const fn from_ref(ref_: &'a T) -> Self

Converts a reference to T to a single element RSlice<'a,T>.

Note:this function does not copy anything.

Example

use abi_stable::std_types::RSlice;

assert_eq!(RSlice::from_ref(&0), RSlice::from_slice(&[0]) );
assert_eq!(RSlice::from_ref(&1), RSlice::from_slice(&[1]) );
assert_eq!(RSlice::from_ref(&2), RSlice::from_slice(&[2]) );
 

pub const fn from_slice(slic: &'a [T]) -> Self

Converts a &[T] to an RSlice<'_,T>.

Example

use abi_stable::std_types::RSlice;
 
let empty:&[u8]=&[];
 
assert_eq!(RSlice::<u8>::from_slice(&[]).as_slice(), empty);
assert_eq!(RSlice::from_slice(&[0]).as_slice()     , &[0][..]);
assert_eq!(RSlice::from_slice(&[0,1]).as_slice()   , &[0,1][..]);
 

pub fn slice<I>(&self, i: I) -> RSlice<'a, T> where
    [T]: Index<I, Output = [T]>, 

Creates an RSlice<'a,T> with access to the range range of elements.

This is an inherent method instead of an implementation of the std::ops::Index trait because it does not return a reference.

Example

use abi_stable::std_types::RSlice;

let slic=RSlice::from_slice(&[0,1,2,3]);

assert_eq!(slic.slice(..),RSlice::from_slice(&[0,1,2,3]));
assert_eq!(slic.slice(..2),RSlice::from_slice(&[0,1]));
assert_eq!(slic.slice(2..),RSlice::from_slice(&[2,3]));
assert_eq!(slic.slice(1..3),RSlice::from_slice(&[1,2]));

pub fn to_rvec(&self) -> RVec<T> where
    T: Clone, 

Creates a new RVec<T> and clones all the elements of this slice into it.

Example

use abi_stable::std_types::{RSlice,RVec};

let slic=RSlice::from_slice(&[0,1,2,3]);

assert_eq!( slic.slice(..).to_rvec(), RVec::from_slice(&[0,1,2,3]) );
assert_eq!( slic.slice(..2).to_rvec(), RVec::from_slice(&[0,1]) );
assert_eq!( slic.slice(2..).to_rvec(), RVec::from_slice(&[2,3]) );
assert_eq!( slic.slice(1..3).to_rvec(), RVec::from_slice(&[1,2]) );

pub const unsafe fn transmute_ref<U>(self) -> RSlice<'a, U> where
    U: 'a, 

Transmutes n RSlice<'a,T> to a RSlice<'a,U>

Safety

This has the same safety requirements as calling std::mem::transmute to transmute a &'a [T] to a &'a [U].

Trait Implementations

impl<'a, T: 'a> AsRef<[T]> for RSlice<'a, T>

pub fn as_ref(&self) -> &[T]

Performs the conversion.

impl<'a, T: 'a> Borrow<[T]> for RSlice<'a, T>

pub fn borrow(&self) -> &[T]

Immutably borrows from an owned value.

impl<'a> BufRead for RSlice<'a, u8>

pub fn fill_buf(&mut self) -> Result<&[u8]>

Returns the contents of the internal buffer, filling it with more data from the inner reader if it is empty.

pub fn consume(&mut self, amt: usize)

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to read.

pub fn read_until(
    &mut self,
    byte: u8,
    buf: &mut Vec<u8>
) -> Result<usize, Error>

Read all bytes into buf until the delimiter byte or EOF is reached.

pub fn read_line(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until a newline (the 0xA byte) is reached, and append them to the provided buffer.

pub fn split(self, byte: u8) -> Split<Self>

Returns an iterator over the contents of this reader split on the byte byte.

pub fn lines(self) -> Lines<Self>

Returns an iterator over the lines of this reader.

impl<'a, T> Clone for RSlice<'a, T>

pub fn clone(&self) -> Self

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a, T> Copy for RSlice<'a, T>

impl<'a, T> Debug for RSlice<'a, T> where
    T: Debug, 

pub fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a, T> Default for RSlice<'a, T>

pub fn default() -> Self

Returns the "default value" for a type.

impl<'a, T: 'a> Deref for RSlice<'a, T>

type Target = [T]

The resulting type after dereferencing.

pub fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'de, T> Deserialize<'de> for RSlice<'de, T> where
    &'de [T]: Deserialize<'de>, 

pub fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<'a, T> Eq for RSlice<'a, T> where
    T: Eq, 

impl<'a, T> From<&'a [T]> for RSlice<'a, T>

pub fn from(this: &'a [T]) -> RSlice<'a, T>

Performs the conversion.

impl<'a, T> From<RSlice<'a, T>> for RCow<'a, [T]> where
    T: Clone, 

pub fn from(this: RSlice<'a, T>) -> Self

Performs the conversion.

impl<'a, T> GetStaticEquivalent_ for RSlice<'a, T> where
    T: __StableAbi,
    T: 'a, 

type StaticEquivalent = _static_RSlice<'static, __GetStaticEquivalent<T>>

impl<'a, T> Hash for RSlice<'a, T> where
    T: Hash, 

pub fn hash<H>(&self, state: &mut H) where
    H: Hasher, 

Feeds this value into the given Hasher.

pub fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<'a, T> Into<&'a [T]> for RSlice<'a, T>

pub fn into(self) -> &'a [T]

Performs the conversion.

impl<'a, T> IntoIterator for RSlice<'a, T>

type Item = &'a T

The type of the elements being iterated over.

type IntoIter = Iter<'a, T>

Which kind of iterator are we turning this into?

pub fn into_iter(self) -> Iter<'a, T>

Creates an iterator from a value.

impl<'a, T> IntoReprRust for RSlice<'a, T>

type ReprRust = &'a [T]

The #[repr(Rust)] equivalent.

pub fn into_rust(self) -> Self::ReprRust

Performs the conversion

impl<'a, T> Ord for RSlice<'a, T> where
    T: Ord, 

pub fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl<'a, T> PartialEq<RSlice<'a, T>> for RSlice<'a, T> where
    T: PartialEq, 

pub fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'a, T> PartialOrd<RSlice<'a, T>> for RSlice<'a, T> where
    T: PartialOrd, 

pub fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]pub fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]pub fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> Read for RSlice<'a, u8>

pub fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

pub fn read_exact(&mut self, buf: &mut [u8]) -> Result<()>

Read the exact number of bytes required to fill buf.

pub fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize>

Read all bytes until EOF in this source, placing them into buf.

pub fn read_vectored(
    &mut self,
    bufs: &mut [IoSliceMut<'_>]
) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

pub fn is_read_vectored(&self) -> bool

🔬 This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

pub unsafe fn initializer(&self) -> Initializer

🔬 This is a nightly-only experimental API. (read_initializer)

Determines if this Reader can work with buffers of uninitialized memory.

pub fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, appending them to buf.

pub fn by_ref(&mut self) -> &mut Self

Creates a "by reference" adaptor for this instance of Read.

pub fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

pub fn chain<R>(self, next: R) -> Chain<Self, R> where
    R: Read, 

Creates an adaptor which will chain this stream with another.

pub fn take(self, limit: u64) -> Take<Self>

Creates an adaptor which will read at most limit bytes from it.

impl<'a, T> Send for RSlice<'a, T> where
    &'a [T]: Send, 

impl<'a, T> Serialize for RSlice<'a, T> where
    T: Serialize, 

pub fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl<'a, T> StableAbi for RSlice<'a, T> where
    T: __StableAbi,
    T: 'a, 

type IsNonZeroType = False

Whether this type has a single invalid bit-pattern.

pub const LAYOUT: &'static TypeLayout

The layout of the type provided by implementors.

pub const ABI_CONSTS: AbiConsts

const-equivalents of the associated types.

impl<'a, T> Sync for RSlice<'a, T> where
    &'a [T]: Sync,