#[derive(Debug)]
pub enum MyStrError {
    MyStrErrorVariant(String),
}

pub enum MyIntError {
    MyIntErrorVariant(i32),
}

impl From<MyIntError> for MyStrError {
    fn from(_e: MyIntError) -> Self {
        MyStrError::MyStrErrorVariant("Converted an int to a string".to_string())
    }
}

fn error_function() -> Result<(), MyIntError> {
    Err(MyIntError::MyIntErrorVariant(12345))
}

fn converting_function() -> Result<(), MyStrError> {
    // doesn't compile:
    error_function()
    // compiles:
    //Ok(error_function()?)
}

fn main() {
    println!("{:?}", converting_function());
}