[−][src]Struct bytes::buf::UninitSlice

#[repr(transparent)]pub struct UninitSlice(_);

Uninitialized byte slice.

Returned by BufMut::chunk_mut(), the referenced byte slice may be uninitialized. The wrapper provides safe access without introducing undefined behavior.

The safety invariants of this wrapper are:

Reading from an UninitSlice is undefined behavior.
Writing uninitialized bytes to an UninitSlice is undefined behavior.

The difference between &mut UninitSlice and &mut [MaybeUninit<u8>] is that it is possible in safe code to write uninitialized bytes to an &mut [MaybeUninit<u8>], which this type prohibits.

Implementations

`impl UninitSlice`[src]

`pub unsafe fn from_raw_parts_mut<'a>( ptr: *mut u8, len: usize ) -> &'a mut UninitSlice`[src]

Create a &mut UninitSlice from a pointer and a length.

Safety

The caller must ensure that ptr references a valid memory region owned by the caller representing a byte slice for the duration of 'a.

Examples

use bytes::buf::UninitSlice;

let bytes = b"hello world".to_vec();
let ptr = bytes.as_ptr() as *mut _;
let len = bytes.len();

let slice = unsafe { UninitSlice::from_raw_parts_mut(ptr, len) };

`pub fn write_byte(&mut self, index: usize, byte: u8)`[src]

Write a single byte at the specified offset.

Panics

The function panics if index is out of bounds.

Examples

use bytes::buf::UninitSlice;

let mut data = [b'f', b'o', b'o'];
let slice = unsafe { UninitSlice::from_raw_parts_mut(data.as_mut_ptr(), 3) };

slice.write_byte(0, b'b');

assert_eq!(b"boo", &data[..]);

`pub fn copy_from_slice(&mut self, src: &[u8])`[src]

Copies bytes from src into self.

The length of src must be the same as self.

Panics

The function panics if src has a different length than self.

Examples

use bytes::buf::UninitSlice;

let mut data = [b'f', b'o', b'o'];
let slice = unsafe { UninitSlice::from_raw_parts_mut(data.as_mut_ptr(), 3) };

slice.copy_from_slice(b"bar");

assert_eq!(b"bar", &data[..]);

`pub fn as_mut_ptr(&mut self) -> *mut u8`[src]

Return a raw pointer to the slice's buffer.

Safety

The caller must not read from the referenced memory and must not write uninitialized bytes to the slice either.

Examples

use bytes::BufMut;

let mut data = [0, 1, 2];
let mut slice = &mut data[..];
let ptr = BufMut::chunk_mut(&mut slice).as_mut_ptr();

`pub fn len(&self) -> usize`[src]

Returns the number of bytes in the slice.

Examples

use bytes::BufMut;

let mut data = [0, 1, 2];
let mut slice = &mut data[..];
let len = BufMut::chunk_mut(&mut slice).len();

assert_eq!(len, 3);

Trait Implementations