rust/src/test/compile-fail/regions-trait-2.rs
Niko Matsakis 3322595e89 Reason about nested free variables that appear in a function
signature.  In a nutshell, the idea is to (1) report an error if, for
a region pointer `'a T`, the lifetime `'a` is longer than any
lifetimes that appear in `T` (in other words, if a borrowed pointer
outlives any portion of its contents) and then (2) use this to assume
that in a function like `fn(self: &'a &'b T)`, the relationship `'a <=
'b` holds. This is needed for #5656.  Fixes #5728.
2013-04-10 07:52:46 -07:00

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Rust

// 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.
// xfail-test #5723
// Test that you cannot escape a borrowed pointer
// into a trait.
struct ctxt { v: uint }
trait get_ctxt {
fn get_ctxt(&self) -> &'self ctxt;
}
struct has_ctxt<'self> { c: &'self ctxt }
impl<'self> get_ctxt for has_ctxt<'self> {
fn get_ctxt(&self) -> &'self ctxt { self.c }
}
fn make_gc() -> @get_ctxt {
let ctxt = ctxt { v: 22u };
let hc = has_ctxt { c: &ctxt };
return @hc as @get_ctxt;
//^~ ERROR source contains borrowed pointer
}
fn main() {
make_gc().get_ctxt().v;
}