Struct Empty 

#[non_exhaustive]
pub struct Empty;

🔬This is a nightly-only experimental API. (core_io #154046)

Empty ignores any data written via Write, and will always be empty (returning zero bytes) when read via Read.

This struct is generally created by calling empty(). Please see the documentation of empty() for more details.

Trait Implementations

impl Clone for Empty

fn clone(&self) -> Empty

Returns a duplicate of the value.

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

where Self:,

Performs copy-assignment from source.

impl Copy for Empty

impl Debug for Empty

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

Formats the value using the given formatter.

impl Default for Empty

fn default() -> Empty

Returns the “default value” for a type.

impl Seek for Empty

fn seek(&mut self, _pos: SeekFrom) -> Result<u64>

Seek to an offset, in bytes, in a stream.

fn stream_len(&mut self) -> Result<u64>

🔬This is a nightly-only experimental API. (seek_stream_len #59359)

Returns the length of this stream (in bytes).

fn stream_position(&mut self) -> Result<u64>

Returns the current seek position from the start of the stream.

fn rewind(&mut self) -> Result<()>

Rewind to the beginning of a stream.

fn seek_relative(&mut self, offset: i64) -> Result<()>

Seeks relative to the current position.

impl SizeHint for Empty

fn upper_bound(&self) -> Option<usize>

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

Returns an upper bound on the number of elements this container-like item contains if it can be determined, otherwise None.

fn lower_bound(&self) -> usize

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

Returns a lower bound on the number of elements this container-like item contains. For example, an array [u8; 12] could return any value between 0 and 12 inclusively as a correct implementation.

final fn size_hint(&self) -> (usize, Option<usize>)

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

Returns an estimate for the number of elements this container like type contains.

impl TrivialClone for Empty

impl Write for Empty

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

Writes a buffer into this writer, returning how many bytes were written.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector #69941)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, _buf: &[u8]) -> Result<()>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, _bufs: &mut [IoSlice<'_>]) -> Result<()>

🔬This is a nightly-only experimental API. (write_all_vectored #70436)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, _args: Arguments<'_>) -> Result<()>

Writes a formatted string into this writer, returning any error encountered.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

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

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.

impl Write for &Empty

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

Writes a buffer into this writer, returning how many bytes were written.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector #69941)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, _buf: &[u8]) -> Result<()>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, _bufs: &mut [IoSlice<'_>]) -> Result<()>

🔬This is a nightly-only experimental API. (write_all_vectored #70436)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, _args: Arguments<'_>) -> Result<()>

Writes a formatted string into this writer, returning any error encountered.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

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

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.