This week I learned 12 — errata

Turns out there’s a much simpler way to read lines from something that is BufRead. BufRead provides an API to iterate over the lines of a Reader. While the examples in #12 still illustrate the point I was making, a simpler implementation is provided below for brevity:

1. Static polymorphism

   fn print_lines<T: BufRead>(b: &mut T) -> Result<(), io::Error> {
    for line in b.lines() {
        println!("{}", line?);
    }
   
    Ok(())
   }
   

2. Dynamic polymorphism

   fn print_lines(b: &mut dyn BufRead) -> Result<(), io::Error> {
    for line in b.lines() {
        println!("{}", line?);
    }
   
    Ok(())
   }