1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
//@ run-pass
#![allow(unused_variables)]
/* Any copyright is dedicated to the Public Domain.
* http://creativecommons.org/publicdomain/zero/1.0/ */
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);
}
|
