summaryrefslogtreecommitdiffstats
path: root/tests/ui/regions/regions-outlives-projection-container.rs
diff options
context:
space:
mode:
Diffstat (limited to 'tests/ui/regions/regions-outlives-projection-container.rs')
-rw-r--r--tests/ui/regions/regions-outlives-projection-container.rs77
1 files changed, 77 insertions, 0 deletions
diff --git a/tests/ui/regions/regions-outlives-projection-container.rs b/tests/ui/regions/regions-outlives-projection-container.rs
new file mode 100644
index 000000000..7b9829cf8
--- /dev/null
+++ b/tests/ui/regions/regions-outlives-projection-container.rs
@@ -0,0 +1,77 @@
+// Test that we are imposing the requirement that every associated
+// type of a bound that appears in the where clause on a struct must
+// outlive the location in which the type appears. Issue #22246.
+
+#![allow(dead_code)]
+#![feature(rustc_attrs)]
+
+pub trait TheTrait {
+ type TheAssocType;
+}
+
+pub struct TheType<'b> {
+ m: [fn(&'b()); 0]
+}
+
+impl<'b> TheTrait for TheType<'b> {
+ type TheAssocType = &'b ();
+}
+
+pub struct WithAssoc<T:TheTrait> {
+ m: [T; 0]
+}
+
+pub struct WithoutAssoc<T> {
+ m: [T; 0]
+}
+
+fn with_assoc<'a,'b>() {
+ // For this type to be valid, the rules require that all
+ // associated types of traits that appear in `WithAssoc` must
+ // outlive 'a. In this case, that means TheType<'b>::TheAssocType,
+ // which is &'b (), must outlive 'a.
+
+ // FIXME (#54943) NLL doesn't enforce WF condition in unreachable code if
+ // `_x` is changed to `_`
+ let _x: &'a WithAssoc<TheType<'b>> = loop { };
+ //~^ ERROR lifetime may not live long enough
+}
+
+fn with_assoc1<'a,'b>() where 'b : 'a {
+ // For this type to be valid, the rules require that all
+ // associated types of traits that appear in `WithAssoc` must
+ // outlive 'a. In this case, that means TheType<'b>::TheAssocType,
+ // which is &'b (), must outlive 'a, so 'b : 'a must hold, and
+ // that is in the where clauses, so we're fine.
+
+ let _x: &'a WithAssoc<TheType<'b>> = loop { };
+}
+
+fn without_assoc<'a,'b>() {
+ // Here there are no associated types but there is a requirement
+ // that `'b:'a` holds because the `'b` appears in `TheType<'b>`.
+
+ let _x: &'a WithoutAssoc<TheType<'b>> = loop { };
+ //~^ ERROR lifetime may not live long enough
+}
+
+fn call_with_assoc<'a,'b>() {
+ // As `with_assoc`, but just checking that we impose the same rule
+ // on the value supplied for the type argument, even when there is
+ // no data.
+
+ call::<&'a WithAssoc<TheType<'b>>>();
+ //~^ ERROR lifetime may not live long enough
+}
+
+fn call_without_assoc<'a,'b>() {
+ // As `without_assoc`, but in a distinct scenario.
+
+ call::<&'a WithoutAssoc<TheType<'b>>>();
+ //~^ ERROR lifetime may not live long enough
+}
+
+fn call<T>() { }
+
+fn main() {
+}