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// xfail-test FIXME #5882
// Weird borrow check bug
// Copyright 2012 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.
// Test cyclic detector when using trait instances.
struct Tree(@mut TreeR);
struct TreeR {
left: Option<Tree>,
right: Option<Tree>,
val: ~to_str
}
trait to_str {
fn to_str_(&self) -> ~str;
}
impl<T:to_str> to_str for Option<T> {
fn to_str_(&self) -> ~str {
match *self {
None => { ~"none" }
Some(ref t) => { ~"some(" + t.to_str_() + ~")" }
}
}
}
impl to_str for int {
fn to_str_(&self) -> ~str { self.to_str() }
}
impl to_str for Tree {
fn to_str_(&self) -> ~str {
let (l, r) = (self.left, self.right);
let val = &self.val;
fmt!("[%s, %s, %s]", val.to_str_(), l.to_str_(), r.to_str_())
}
}
fn foo<T:to_str>(x: T) -> ~str { x.to_str_() }
pub fn main() {
let t1 = Tree(@mut TreeR{left: None,
right: None,
val: ~1 as ~to_str });
let t2 = Tree(@mut TreeR{left: Some(t1),
right: Some(t1),
val: ~2 as ~to_str });
let expected = ~"[2, some([1, none, none]), some([1, none, none])]";
assert!(t2.to_str_() == expected);
assert!(foo(t2) == expected);
t1.left = Some(t2); // create cycle
}
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