use chainerror::*;
use std::error::Error;
use std::result::Result;
fn do_some_io() -> Result<(), Box<Error>> {
Err("do_some_io error")?;
Ok(())
}
fn func2() -> Result<(), Box<Error>> {
do_some_io().map_err(|e| cherr!(e, "func2 error"))?;
Ok(())
}
fn func1() -> Result<(), Box<Error>> {
func2().map_err(|e| cherr!(e, "func1 error"))?;
Ok(())
}
fn main() -> Result<(), Box<Error>> {
if let Err(e) = func1() {
eprintln!("{:?}", e);
}
Ok(())
}