// 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 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. // A dummy trait/impl that work close over any type. The trait will // be parameterized by a region due to the &self/int constraint. trait foo { fn foo(i: &self/int) -> int; } impl T: foo { fn foo(i: &self/int) -> int {*i} } fn to_foo(t: T) { // This version is ok because, although T may contain borrowed // pointers, it never escapes the fn body. We know this because // the type of foo includes a region which will be resolved to // the fn body itself. let v = &3; let x = {f:t} as foo; assert x.foo(v) == 3; } fn to_foo_2(t: T) -> foo { // Not OK---T may contain borrowed ptrs and it is going to escape // as part of the returned foo value {f:t} as foo //~ ERROR value may contain borrowed pointers; use `&static` bound } fn to_foo_3(t: T) -> foo { // OK---T may escape as part of the returned foo value, but it is // owned and hence does not contain borrowed ptrs {f:t} as foo } fn main() { }