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use std::io::{Result, Write};
pub struct BroadcastWriter<A: Write, B: Write> {
primary: A,
secondary: B,
}
impl<A: Write, B: Write> BroadcastWriter<A, B> {
pub fn new(primary: A, secondary: B) -> BroadcastWriter<A, B> {
BroadcastWriter {
primary: primary,
secondary: secondary,
}
}
}
impl<A: Write, B: Write> Write for BroadcastWriter<A, B> {
fn write(&mut self, data: &[u8]) -> Result<usize> {
let n = try!(self.primary.write(data));
try!(self.secondary.write_all(&data[..n]));
Ok(n)
}
fn flush(&mut self) -> Result<()> {
self.primary.flush().and(self.secondary.flush())
}
}
#[cfg(test)]
mod tests {
use super::*;
use std::io::Write;
#[test]
fn broadcast() {
let mut first = Vec::new();
let mut second = Vec::new();
{
let mut broadcaster = BroadcastWriter::new(&mut first, &mut second);
let _ = broadcaster.write(b"it's over 9000!");
}
assert_eq!(first, second);
}
}