use std::fmt; // Import the `fmt` module.

#[derive(Debug)]
struct DivideError {
    details: String
}

impl DivideError {
    fn new(msg: &str) -> DivideError {
        DivideError{details: msg.to_string()}
    }
}

impl fmt::Display for DivideError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f,"{}",self.details)
    }
}

impl std::error::Error for DivideError {
    fn description(&self) -> &str {
        &self.details
    }
}

fn divide(a: i32, b: i32) -> Result {
    if b != 0 {
        Ok(a / b)
    } else {
        Err(DivideError::new("can not devide 0"))
    }
}

fn divideWrap() -> Result {
    let result = divide(10, 5)?;
    println!("{}", result);
    Ok(())
}

fn main() {
    divideWrap();
}