Function std::io::copyUnstable

pub fn copy<R: Read, W: Write>(r: &mut R, w: &mut W) -> Result<u64>

Copies the entire contents of a reader into a writer.

This function will continuously read data from r and then write it into w in a streaming fashion until r returns EOF.

On success the total number of bytes that were copied from r to w is returned.

Errors

This function will return an error immediately if any call to read or write returns an error. All instances of ErrorKind::Interrupted are handled by this function and the underlying operation is retried.