| // 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. |
| |
| /* Any copyright is dedicated to the Public Domain. |
| * http://creativecommons.org/publicdomain/zero/1.0/ */ |
| |
| #![feature(unboxed_closures)] |
| |
| fn call_it<F>(f: F) |
| where F : FnOnce(String) -> String |
| { |
| println!("{}", f("Fred".to_string())) |
| } |
| |
| fn call_a_thunk<F>(f: F) where F: FnOnce() { |
| f(); |
| } |
| |
| fn call_this<F>(f: F) where F: FnOnce(&str) + Send { |
| f("Hello!"); |
| } |
| |
| fn call_bare(f: fn(&str)) { |
| f("Hello world!") |
| } |
| |
| fn call_bare_again(f: extern "Rust" fn(&str)) { |
| f("Goodbye world!") |
| } |
| |
| pub fn main() { |
| // Procs |
| |
| let greeting = "Hello ".to_string(); |
| call_it(|s| { |
| format!("{}{}", greeting, s) |
| }); |
| |
| let greeting = "Goodbye ".to_string(); |
| call_it(|s| format!("{}{}", greeting, s)); |
| |
| let greeting = "How's life, ".to_string(); |
| call_it(|s: String| -> String { |
| format!("{}{}", greeting, s) |
| }); |
| |
| // Closures |
| |
| call_a_thunk(|| println!("Hello world!")); |
| |
| call_this(|s| println!("{}", s)); |
| |
| // External functions |
| |
| fn foo(s: &str) {} |
| call_bare(foo); |
| |
| call_bare_again(foo); |
| } |