// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. #[derive(Clone, Debug)] enum foo { a(usize), b(String), } fn check_log(exp: String, v: T) { assert_eq!(exp, format!("{:?}", v)); } pub fn main() { let mut x = Some(foo::a(22)); let exp = "Some(a(22))".to_string(); let act = format!("{:?}", x); assert_eq!(act, exp); check_log(exp, x); x = None; let exp = "None".to_string(); let act = format!("{:?}", x); assert_eq!(act, exp); check_log(exp, x); }