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use std::fs::File;
use std::path::PathBuf;
use std::io;
use std::io::{Read, BufRead, BufReader, Write};
pub struct InputReader<'a>(Box<BufRead + 'a>);
impl<'a> Read for InputReader<'a> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.0.read(buf)
}
}
impl<'a> BufRead for InputReader<'a> {
fn fill_buf(&mut self) -> io::Result<&[u8]> {
self.0.fill_buf()
}
fn consume(&mut self, amt: usize) {
self.0.consume(amt)
}
}
pub enum Input {
Stdin(io::Stdin),
File(PathBuf),
}
impl Input {
pub fn from<P>(path: Option<P>) -> Self
where P: Into<PathBuf>
{
match path {
Some(path) => Input::File(path.into()),
None => Input::Stdin(io::stdin()),
}
}
pub fn buf_read(&self) -> io::Result<InputReader> {
match self {
&Input::Stdin(ref stdin) => Result::Ok(InputReader(Box::new(stdin.lock()))),
&Input::File(ref path) => {
File::open(path).map(BufReader::new).map(Box::new).map(|r| InputReader(r))
}
}
}
}
pub enum Output {
Stdout(io::Stdout),
File(PathBuf),
}
impl Output {
pub fn from<P>(path: Option<P>) -> Self
where P: Into<PathBuf>
{
match path {
Some(path) => Output::File(path.into()),
None => Output::Stdout(io::stdout()),
}
}
pub fn write<'a>(&'a self) -> io::Result<Box<Write + 'a>> {
match self {
&Output::Stdout(ref stdout) => Result::Ok(Box::new(stdout.lock())),
&Output::File(ref path) => Result::Ok(Box::new(try!(File::create(path)))),
}
}
}