1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Test that we are imposing the requirement that every associated
12 // type of a bound that appears in the where clause on a struct must
13 // outlive the location in which the type appears. Issue #22246.
16 #![feature(rustc_attrs)]
18 use std::marker::PhantomFn;
20 ///////////////////////////////////////////////////////////////////////////
22 pub trait TheTrait: PhantomFn<Self, Self> {
26 pub struct TheType<'b> {
30 impl<'b> TheTrait for TheType<'b> {
31 type TheAssocType = &'b ();
34 ///////////////////////////////////////////////////////////////////////////
36 pub struct WithAssoc<T:TheTrait> {
40 pub struct WithoutAssoc<T> {
44 fn with_assoc<'a,'b>() {
45 // For this type to be valid, the rules require that all
46 // associated types of traits that appear in `WithAssoc` must
47 // outlive 'a. In this case, that means TheType<'b>::TheAssocType,
48 // which is &'b (), must outlive 'a.
50 let _: &'a WithAssoc<TheType<'b>> = loop { }; //~ ERROR cannot infer
53 fn with_assoc1<'a,'b>() where 'b : 'a {
54 // For this type to be valid, the rules require that all
55 // associated types of traits that appear in `WithAssoc` must
56 // outlive 'a. In this case, that means TheType<'b>::TheAssocType,
57 // which is &'b (), must outlive 'a, so 'b : 'a must hold, and
58 // that is in the where clauses, so we're fine.
60 let _: &'a WithAssoc<TheType<'b>> = loop { };
63 fn without_assoc<'a,'b>() {
64 // Here there are no associated types and the `'b` appearing in
65 // `TheType<'b>` is purely covariant, so there is no requirement
66 // that `'b:'a` holds.
68 let _: &'a WithoutAssoc<TheType<'b>> = loop { };
71 fn call_with_assoc<'a,'b>() {
72 // As `with_assoc`, but just checking that we impose the same rule
73 // on the value supplied for the type argument, even when there is
76 call::<&'a WithAssoc<TheType<'b>>>();
77 //~^ ERROR cannot infer
80 fn call_without_assoc<'a,'b>() {
81 // As `without_assoc`, but in a distinct scenario.
83 call::<&'a WithoutAssoc<TheType<'b>>>();