1 // run-pass
2 #![allow(unused_must_use)]
3 // Tests that a heterogeneous list of existential `dyn` types can be put inside an Arc
4 // and shared between threads as long as all types fulfill Send.
5
6 // ignore-emscripten no threads support
7
8 use std::sync::Arc;
9 use std::sync::mpsc::channel;
10 use std::thread;
11
12 trait Pet {
name(&self, blk: Box<dyn FnMut(&str)>)13 fn name(&self, blk: Box<dyn FnMut(&str)>);
num_legs(&self) -> usize14 fn num_legs(&self) -> usize;
of_good_pedigree(&self) -> bool15 fn of_good_pedigree(&self) -> bool;
16 }
17
18 struct Catte {
19 num_whiskers: usize,
20 name: String,
21 }
22
23 struct Dogge {
24 bark_decibels: usize,
25 tricks_known: usize,
26 name: String,
27 }
28
29 struct Goldfyshe {
30 swim_speed: usize,
31 name: String,
32 }
33
34 impl Pet for Catte {
name(&self, mut blk: Box<dyn FnMut(&str)>)35 fn name(&self, mut blk: Box<dyn FnMut(&str)>) { blk(&self.name) }
num_legs(&self) -> usize36 fn num_legs(&self) -> usize { 4 }
of_good_pedigree(&self) -> bool37 fn of_good_pedigree(&self) -> bool { self.num_whiskers >= 4 }
38 }
39 impl Pet for Dogge {
name(&self, mut blk: Box<dyn FnMut(&str)>)40 fn name(&self, mut blk: Box<dyn FnMut(&str)>) { blk(&self.name) }
num_legs(&self) -> usize41 fn num_legs(&self) -> usize { 4 }
of_good_pedigree(&self) -> bool42 fn of_good_pedigree(&self) -> bool {
43 self.bark_decibels < 70 || self.tricks_known > 20
44 }
45 }
46 impl Pet for Goldfyshe {
name(&self, mut blk: Box<dyn FnMut(&str)>)47 fn name(&self, mut blk: Box<dyn FnMut(&str)>) { blk(&self.name) }
num_legs(&self) -> usize48 fn num_legs(&self) -> usize { 0 }
of_good_pedigree(&self) -> bool49 fn of_good_pedigree(&self) -> bool { self.swim_speed >= 500 }
50 }
51
main()52 pub fn main() {
53 let catte = Catte { num_whiskers: 7, name: "alonzo_church".to_string() };
54 let dogge1 = Dogge {
55 bark_decibels: 100,
56 tricks_known: 42,
57 name: "alan_turing".to_string(),
58 };
59 let dogge2 = Dogge {
60 bark_decibels: 55,
61 tricks_known: 11,
62 name: "albert_einstein".to_string(),
63 };
64 let fishe = Goldfyshe {
65 swim_speed: 998,
66 name: "alec_guinness".to_string(),
67 };
68 let arc = Arc::new(vec![
69 Box::new(catte) as Box<dyn Pet+Sync+Send>,
70 Box::new(dogge1) as Box<dyn Pet+Sync+Send>,
71 Box::new(fishe) as Box<dyn Pet+Sync+Send>,
72 Box::new(dogge2) as Box<dyn Pet+Sync+Send>]);
73 let (tx1, rx1) = channel();
74 let arc1 = arc.clone();
75 let t1 = thread::spawn(move|| { check_legs(arc1); tx1.send(()); });
76 let (tx2, rx2) = channel();
77 let arc2 = arc.clone();
78 let t2 = thread::spawn(move|| { check_names(arc2); tx2.send(()); });
79 let (tx3, rx3) = channel();
80 let arc3 = arc.clone();
81 let t3 = thread::spawn(move|| { check_pedigree(arc3); tx3.send(()); });
82 rx1.recv();
83 rx2.recv();
84 rx3.recv();
85 t1.join();
86 t2.join();
87 t3.join();
88 }
89
check_legs(arc: Arc<Vec<Box<dyn Pet+Sync+Send>>>)90 fn check_legs(arc: Arc<Vec<Box<dyn Pet+Sync+Send>>>) {
91 let mut legs = 0;
92 for pet in arc.iter() {
93 legs += pet.num_legs();
94 }
95 assert!(legs == 12);
96 }
check_names(arc: Arc<Vec<Box<dyn Pet+Sync+Send>>>)97 fn check_names(arc: Arc<Vec<Box<dyn Pet+Sync+Send>>>) {
98 for pet in arc.iter() {
99 pet.name(Box::new(|name| {
100 assert!(name.as_bytes()[0] == 'a' as u8 && name.as_bytes()[1] == 'l' as u8);
101 }))
102 }
103 }
check_pedigree(arc: Arc<Vec<Box<dyn Pet+Sync+Send>>>)104 fn check_pedigree(arc: Arc<Vec<Box<dyn Pet+Sync+Send>>>) {
105 for pet in arc.iter() {
106 assert!(pet.of_good_pedigree());
107 }
108 }
109