rust•armanazi•error•[E0782]: trait objects must include the `dyn` keyword
fn main() -> Result<(), Error> {
let f = File::open("hello.txt")?;
Ok(())
}
//folowing is not error exist
use std::error::Error;
use std::fs::File;
fn main() -> Result<(), Box<dyn Error>> {
let f = File::open("hello.txt")?;
Ok(())
}