Function http_req::request::copy_until

pub fn copy_until<R: ?Sized, W: ?Sized>(
    reader: &mut R, 
    writer: &mut W, 
    val: &[u8]
) -> Result<usize, Error> where
    R: Read,
    W: Write, 

Copies data from reader to writer until the specified value is reached. Returns how many bytes has been read.