try_from.rs

#[cfg(test)]
mod tests {
    use std::convert::TryInto;
    use std::num::TryFromIntError;

    #[test]
    fn it_works() {
        let a = 1i16;
        let b: Result<i8, TryFromIntError> = a.try_into();
        assert!(b.is_ok());
    }

    #[test]
    fn overflow() {
        let a = 256i16;
        let b: Result<i8, TryFromIntError> = a.try_into();
        assert!(b.is_err());
    }
}