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#![allow(dead_code)]
use std::io::{self, Write, Stdout, Result};
use std::fs::{File, OpenOptions};
use std::fmt::{Display};
pub struct OutputWriter<W: Write> {
writer: W,
buf: Vec<u8>,
}
impl OutputWriter<Stdout> {
pub fn new() -> Self { Self::from_writer(io::stdout()) }
}
impl OutputWriter<File> {
pub fn from_file(path: &str) -> Self {
let file = OpenOptions::new()
.write(true)
.create(true)
.open(path);
Self::from_writer(file.unwrap())
}
}
impl<W: Write> OutputWriter<W> {
pub fn from_writer(writer: W) -> Self {
let buf = Vec::with_capacity(1 << 16);
Self { writer, buf }
}
pub fn print<T: Display>(&mut self, t: T) {
write!(self, "{}", t).unwrap();
}
pub fn prints<T: Display>(&mut self, t: T) {
write!(self, "{} ", t).unwrap();
}
pub fn println<T: Display>(&mut self, t: T) {
writeln!(self, "{}", t).unwrap();
}
}
impl<W: Write> Write for OutputWriter<W> {
fn write(&mut self, bytes: &[u8]) -> Result<usize> {
self.buf.extend(bytes);
Ok(bytes.len())
}
fn flush(&mut self) -> Result<()> {
self.writer.write_all(&self.buf)?;
self.writer.flush()?;
self.buf.clear();
Ok(())
}
}
impl<W: Write> Drop for OutputWriter<W> {
fn drop(&mut self) { self.flush().unwrap(); }
}