pub async fn copy_buf<'a, R, W>(
reader: &'a mut R,
writer: &'a mut W
) -> Result<u64> where
R: AsyncBufRead + Unpin + ?Sized,
W: AsyncWrite + Unpin + ?Sized,
Expand description
Asynchronously copies the entire contents of a reader into a writer.
This function returns a future that will continuously read data from
reader
and then write it into writer
in a streaming fashion until
reader
returns EOF.
On success, the total number of bytes that were copied from reader
to
writer
is returned.
Errors
The returned future will finish with an error will return an error
immediately if any call to poll_fill_buf
or poll_write
returns an
error.
Examples
use tokio::io;
let mut reader: &[u8] = b"hello";
let mut writer: Vec<u8> = vec![];
io::copy_buf(&mut reader, &mut writer).await?;
assert_eq!(b"hello", &writer[..]);