extern crate from_int; // contains the trait
#[macro_use] extern crate from_int_derive; // contains the macro

use from_int::FromInt;

#[derive(FromInt, Debug, PartialEq)]
enum TestEnum {
    VariantOne = 1,
    VariantTwo = 2,
    VariantThree = 528,
    VariantX = 999
}

assert_eq!(TestEnum::VariantOne, TestEnum::from_int(1).unwrap());
assert_eq!(TestEnum::VariantTwo, TestEnum::from_int(2).unwrap());
assert_eq!(TestEnum::VariantThree, TestEnum::from_int(528).unwrap());
assert_eq!(TestEnum::VariantX, TestEnum::from_int(999).unwrap());

// This would panic:
assert_eq!(None, TestEnum::from_int(123));