Usando Read y BufRead, nos podemos abstraer a un vector de u8
use std::io::{BufRead, BufReader, Read, Result};
fn count_lines<R: Read>(reader: R) -> usize {
let buf_reader = BufReader::new(reader);
buf_reader.lines().count()
}
fn main() -> Result<()> {
let slice: &[u8] = b"foo\nbar\nbaz\n";
println!("lines in slice: {}", count_lines(slice));
let file = std::fs::File::open(std::env::current_exe()?)?;
println!("lines in file: {}", count_lines(file));
Ok(())
}
De manera similar, Write nos permite abstraernos de igual forma:
use std::io::{Result, Write};
fn log<W: Write>(writer: &mut W, msg: &str) -> Result<()> {
writer.write_all(msg.as_bytes())?;
writer.write_all("\n".as_bytes())
}
fn main() -> Result<()> {
let mut buffer = Vec::new();
log(&mut buffer, "Hello")?;
log(&mut buffer, "World")?;
println!("Logged: {:?}", buffer);
Ok(())
}
