Struct iowrap::Ignore

pub struct Ignore {}

Ignore all IO requests made on this object.

• For Write, that means reporting success always, but not doing anything.
• For Read and Seek, that means acting like an immutable empty file.

This may confuse things which use Write and Seek together, as writing to an Ignore does not advance its seek position, which is not what would happen with a File or Cursor or similar. The Seek implementation ignores out of bound seeks, negative seeks, etc., in the hope of maybe mitigating this a bit.

Example

use std::io;
use iowrap::Ignore;

fn main() {
    assert_eq!(0, io::copy(&mut Ignore::new(), &mut Ignore::new()).unwrap());
}

Methods

impl Ignore

pub fn new() -> Self

Trait Implementations

impl Clone for Ignore

Important traits for Ignore

impl Write for Ignoreimpl Read for Ignore

fn clone(&self) -> Ignore

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Default for Ignore

fn default() -> Self

Returns the "default value" for a type.

impl Copy for Ignore

impl Debug for Ignore

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

Formats the value using the given formatter.

impl Write for Ignore

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

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

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

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

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

Attempts to write an entire buffer into this writer.

fn write_fmt(&mut self, _fmt: Arguments) -> Result<()>

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

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

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

impl Seek for Ignore

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

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

impl Read for Ignore

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.

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

Read the exact number of bytes required to fill buf.

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.

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

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

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

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

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

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

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an [Iterator] over its bytes.

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

Creates an adaptor which will chain this stream with another.

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

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

impl BufRead for Ignore

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.

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.

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.

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.

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

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

fn lines(self) -> Lines<Self>

Returns an iterator over the lines of this reader.