// Copyright 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 <LICENSE-APACHE or// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your// option. This file may not be copied, modified, or distributed// except according to those terms.macro_rules!do_block{($val:block)=>{$val}}fnmain(){lets;do_block!({s="it works!";});assert_eq!(s,"it works!");}