Struct BorrowedBuf 

pub struct BorrowedBuf<'data> { /* private fields */ }

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

A borrowed buffer of initially uninitialized bytes, which is incrementally filled.

This type makes it safer to work with MaybeUninit buffers, such as to read into a buffer without having to initialize it first. It tracks the region of bytes that have been filled and the region that remains uninitialized.

The contents of the buffer can be visualized as:

[                         capacity                            ]
[ len: filled and initialized | capacity - len: uninitialized ]

Note that BorrowedBuf does not distinguish between uninitialized data and data that was previously initialized but no longer contains valid data.

A BorrowedBuf is created around some existing data (or capacity for data) via a unique reference (&mut). The BorrowedBuf can be configured (e.g., using clear or set_len), but cannot be directly written. To write into the buffer, use unfilled to create a BorrowedCursor. The cursor has write-only access to the unfilled portion of the buffer.

The lifetime 'data is a bound on the lifetime of the underlying data.

Implementations

impl<'data> BorrowedBuf<'data>

pub fn capacity(&self) -> usize

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns the total capacity of the buffer.

pub fn len(&self) -> usize

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns the length of the filled part of the buffer.

pub fn filled(&self) -> &[u8]

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns a shared reference to the filled portion of the buffer.

pub fn filled_mut(&mut self) -> &mut [u8]

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns a mutable reference to the filled portion of the buffer.

pub fn into_filled(self) -> &'data [u8]

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns a shared reference to the filled portion of the buffer with its original lifetime.

pub fn into_filled_mut(self) -> &'data mut [u8]

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns a mutable reference to the filled portion of the buffer with its original lifetime.

pub fn unfilled<'this>(&'this mut self) -> BorrowedCursor<'this>

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns a cursor over the unfilled part of the buffer.

pub fn clear(&mut self) -> &mut BorrowedBuf<'data>

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Clears the buffer, resetting the filled region to empty.

The contents of the buffer are not modified.

Trait Implementations

impl Debug for BorrowedBuf<'_>

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

Formats the value using the given formatter.

impl<'data> From<&'data mut [MaybeUninit<u8>]> for BorrowedBuf<'data>

Creates a new BorrowedBuf from an uninitialized buffer.

Use set_filled if part of the buffer is known to be already filled.

fn from(buf: &'data mut [MaybeUninit<u8>]) -> BorrowedBuf<'data>

Converts to this type from the input type.

impl<'data> From<&'data mut [u8]> for BorrowedBuf<'data>

Creates a new BorrowedBuf from a fully initialized slice.

fn from(slice: &'data mut [u8]) -> BorrowedBuf<'data>

Converts to this type from the input type.

impl<'data> From<BorrowedCursor<'data>> for BorrowedBuf<'data>

Creates a new BorrowedBuf from a cursor.

Use BorrowedCursor::with_unfilled_buf instead for a safer alternative.

fn from(buf: BorrowedCursor<'data>) -> BorrowedBuf<'data>

Converts to this type from the input type.