Struct std::io::Chain

pub struct Chain<T, U> {
    first: T,
    second: U,
    done_first: bool,
}

Adapter to chain together two readers.

This struct is generally created by calling chain on a reader. Please see the documentation of chain for more details.

Fields

first: T

second: U

done_first: bool

Implementations

impl<T, U> Chain<T, U>

pub fn into_inner(self) -> (T, U)

Consumes the Chain, returning the wrapped readers.

Examples

use std::io;
use std::io::prelude::*;
use std::fs::File;

fn main() -> io::Result<()> {
    let mut foo_file = File::open("foo.txt")?;
    let mut bar_file = File::open("bar.txt")?;

    let chain = foo_file.chain(bar_file);
    let (foo_file, bar_file) = chain.into_inner();
    Ok(())
}

pub fn get_ref(&self) -> (&T, &U)

Gets references to the underlying readers in this Chain.

Examples

use std::io;
use std::io::prelude::*;
use std::fs::File;

fn main() -> io::Result<()> {
    let mut foo_file = File::open("foo.txt")?;
    let mut bar_file = File::open("bar.txt")?;

    let chain = foo_file.chain(bar_file);
    let (foo_file, bar_file) = chain.get_ref();
    Ok(())
}

pub fn get_mut(&mut self) -> (&mut T, &mut U)

Gets mutable references to the underlying readers in this Chain.

Care should be taken to avoid modifying the internal I/O state of the underlying readers as doing so may corrupt the internal state of this Chain.

Examples

use std::io;
use std::io::prelude::*;
use std::fs::File;

fn main() -> io::Result<()> {
    let mut foo_file = File::open("foo.txt")?;
    let mut bar_file = File::open("bar.txt")?;

    let mut chain = foo_file.chain(bar_file);
    let (foo_file, bar_file) = chain.get_mut();
    Ok(())
}

Trait Implementations

impl<T: BufRead, U: BufRead> BufRead for Chain<T, U>

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 has_data_left(&mut self) -> Result<bool>

🔬This is a nightly-only experimental API. (buf_read_has_data_left #86423)

Check if the underlying Read has any data left to be read.

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

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

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

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

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

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

fn lines(self) -> Lines<Self> where Self: Sized,

Returns an iterator over the lines of this reader.

impl<T: Debug, U: Debug> Debug for Chain<T, U>

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

Formats the value using the given formatter.

impl<T: Read, U: Read> Read for Chain<T, U>

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_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize>

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

fn is_read_vectored(&self) -> bool

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

Determines if this Reader has an efficient read_vectored implementation.

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

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

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

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

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

Read the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<()>

🔬This is a nightly-only experimental API. (read_buf #78485)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<()>

🔬This is a nightly-only experimental API. (read_buf #78485)

Read the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Selfwhere Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self> where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

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

Creates an adapter which will chain this stream with another.

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

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

impl<T, U> SizeHint for Chain<T, U>

fn lower_bound(&self) -> usize

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

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