Add a run-pass test for existential traits in ARCs.

Author: bblum

src/test/run-pass/trait-bounds-in-arc.rs

@@ -0,0 +1,103 @@
+// Copyright 2013 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.
+
+// Tests that a heterogeneous list of existential types can be put inside an ARC
+// and shared between tasks as long as all types fulfill Const+Owned.
+
+// xfail-fast
+
+extern mod extra;
+use extra::arc;
+use std::comm;
+use std::task;
+use std::cell;
+
+trait Pet {
+    fn name(&self, blk: &fn(&str));
+    fn num_legs(&self) -> uint;
+    fn of_good_pedigree(&self) -> bool;
+}
+
+struct Catte {
+    num_whiskers: uint,
+    name: ~str,
+}
+
+struct Dogge {
+    bark_decibels: uint,
+    tricks_known: uint,
+    name: ~str,
+}
+
+struct Goldfyshe {
+    swim_speed: uint,
+    name: ~str,
+}
+
+impl Pet for Catte {
+    fn name(&self, blk: &fn(&str)) { blk(self.name) }
+    fn num_legs(&self) -> uint { 4 }
+    fn of_good_pedigree(&self) -> bool { self.num_whiskers >= 4 }
+}
+impl Pet for Dogge {
+    fn name(&self, blk: &fn(&str)) { blk(self.name) }
+    fn num_legs(&self) -> uint { 4 }
+    fn of_good_pedigree(&self) -> bool {
+        self.bark_decibels < 70 || self.tricks_known > 20
+    }
+}
+impl Pet for Goldfyshe {
+    fn name(&self, blk: &fn(&str)) { blk(self.name) }
+    fn num_legs(&self) -> uint { 0 }
+    fn of_good_pedigree(&self) -> bool { self.swim_speed >= 500 }
+}
+
+fn main() {
+    let catte = Catte { num_whiskers: 7, name: ~"alonzo_church" };
+    let dogge1 = Dogge { bark_decibels: 100, tricks_known: 42, name: ~"alan_turing" };
+    let dogge2 = Dogge { bark_decibels: 55,  tricks_known: 11, name: ~"albert_einstein" };
+    let fishe = Goldfyshe { swim_speed: 998, name: ~"alec_guinness" };
+    let arc = arc::ARC(~[~catte  as ~Pet:Const+Owned,
+                         ~dogge1 as ~Pet:Const+Owned,
+                         ~fishe  as ~Pet:Const+Owned,
+                         ~dogge2 as ~Pet:Const+Owned]);
+    let (p1,c1) = comm::stream();
+    let arc1 = cell::Cell::new(arc.clone());
+    do task::spawn { check_legs(arc1.take()); c1.send(()); }
+    let (p2,c2) = comm::stream();
+    let arc2 = cell::Cell::new(arc.clone());
+    do task::spawn { check_names(arc2.take()); c2.send(()); }
+    let (p3,c3) = comm::stream();
+    let arc3 = cell::Cell::new(arc.clone());
+    do task::spawn { check_pedigree(arc3.take()); c3.send(()); }
+    p1.recv();
+    p2.recv();
+    p3.recv();
+}
+
+fn check_legs(arc: arc::ARC<~[~Pet:Const+Owned]>) {
+    let mut legs = 0;
+    for arc.get().iter().advance |pet| {
+        legs += pet.num_legs();
+    }
+    assert!(legs == 12);
+}
+fn check_names(arc: arc::ARC<~[~Pet:Const+Owned]>) {
+    for arc.get().iter().advance |pet| {
+        do pet.name |name| {
+            assert!(name[0] == 'a' as u8 && name[1] == 'l' as u8);
+        }
+    }
+}
+fn check_pedigree(arc: arc::ARC<~[~Pet:Const+Owned]>) {
+    for arc.get().iter().advance |pet| {
+        assert!(pet.of_good_pedigree());
+    }
+}