69 lines
1.5 KiB
Rust
69 lines
1.5 KiB
Rust
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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/* Any copyright is dedicated to the Public Domain.
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* http://creativecommons.org/publicdomain/zero/1.0/ */
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#![feature(unboxed_closures, old_io)]
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use std::mem;
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use std::old_io::stdio::println;
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fn call_it<F>(f: F)
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where F : FnOnce(String) -> String
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{
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println!("{}", f("Fred".to_string()))
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}
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fn call_a_thunk<F>(f: F) where F: FnOnce() {
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f();
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}
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fn call_this<F>(f: F) where F: FnOnce(&str) + Send {
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f("Hello!");
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}
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fn call_bare(f: fn(&str)) {
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f("Hello world!")
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}
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fn call_bare_again(f: extern "Rust" fn(&str)) {
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f("Goodbye world!")
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}
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pub fn main() {
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// Procs
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let greeting = "Hello ".to_string();
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call_it(|s| {
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format!("{}{}", greeting, s)
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});
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let greeting = "Goodbye ".to_string();
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call_it(|s| format!("{}{}", greeting, s));
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let greeting = "How's life, ".to_string();
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call_it(|s: String| -> String {
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format!("{}{}", greeting, s)
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});
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// Closures
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call_a_thunk(|| println!("Hello world!"));
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call_this(|s| println!("{}", s));
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// External functions
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call_bare(println);
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call_bare_again(println);
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}
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