| // Copyright 2014 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 that we can derive lifetime bounds on type parameters |
| // from trait inheritance. |
| |
| trait Static : 'static { } |
| |
| trait Is<'a> : 'a { } |
| |
| struct Inv<'a> { |
| x: Option<&'a mut &'a isize> |
| } |
| |
| fn check_bound<'a,A:'a>(x: Inv<'a>, a: A) { } |
| |
| // In all of these cases, we can derive a bound for A that is longer |
| // than 'a based on the trait bound of A: |
| |
| fn foo1<'a,A:Static>(x: Inv<'a>, a: A) { |
| check_bound(x, a) |
| } |
| |
| fn foo2<'a,A:Static>(x: Inv<'static>, a: A) { |
| check_bound(x, a) |
| } |
| |
| fn foo3<'a,A:Is<'a>>(x: Inv<'a>, a: A) { |
| check_bound(x, a) |
| } |
| |
| // In these cases, there is no trait bound, so we cannot derive any |
| // bound for A and we get an error: |
| |
| fn bar1<'a,A>(x: Inv<'a>, a: A) { |
| check_bound(x, a) //~ ERROR parameter type `A` may not live long enough |
| } |
| |
| fn bar2<'a,'b,A:Is<'b>>(x: Inv<'a>, y: Inv<'b>, a: A) { |
| check_bound(x, a) //~ ERROR parameter type `A` may not live long enough |
| } |
| |
| fn main() { } |