Add 'static lifetime suggestion when GAT implied 'static requirement from HRTB

3 files changed, 120 insertions, 0 deletions

diff --git a/tests/ui/lifetimes/issue-105507.fixed b/tests/ui/lifetimes/issue-105507.fixed
new file mode 100644
index 00000000000..277ce8a77e9
--- /dev/null
+++ b/tests/ui/lifetimes/issue-105507.fixed
@@ -0,0 +1,43 @@
+// run-rustfix
+//
+#![allow(warnings)]
+struct Wrapper<'a, T: ?Sized>(&'a T);
+
+trait Project {
+    type Projected<'a> where Self: 'a;
+    fn project(this: Wrapper<'_, Self>) -> Self::Projected<'_>;
+}
+trait MyTrait {}
+trait ProjectedMyTrait {}
+
+impl<T> Project for Option<T> {
+    type Projected<'a> = Option<Wrapper<'a, T>> where T: 'a;
+    fn project(this: Wrapper<'_, Self>) -> Self::Projected<'_> {
+        this.0.as_ref().map(Wrapper)
+    }
+}
+
+impl<T: MyTrait> MyTrait for Option<Wrapper<'_, T>> {}
+
+impl<T: ProjectedMyTrait> MyTrait for Wrapper<'_, T> {}
+
+impl<T> ProjectedMyTrait for T
+    where
+        T: Project,
+        for<'a> T::Projected<'a>: MyTrait,
+        //~^ NOTE due to current limitations in the borrow checker, this implies a `'static` lifetime
+        //~| NOTE due to current limitations in the borrow checker, this implies a `'static` lifetime
+{}
+
+fn require_trait<T: MyTrait>(_: T) {}
+
+fn foo<T : MyTrait + 'static + 'static, U : MyTrait + 'static + 'static>(wrap: Wrapper<'_, Option<T>>, wrap1: Wrapper<'_, Option<U>>) {
+    //~^ HELP consider restricting the type parameter to the `'static` lifetime
+    //~| HELP consider restricting the type parameter to the `'static` lifetime
+    require_trait(wrap);
+    //~^ ERROR `T` does not live long enough
+    require_trait(wrap1);
+    //~^ ERROR `U` does not live long enough
+}
+
+fn main() {}
diff --git a/tests/ui/lifetimes/issue-105507.rs b/tests/ui/lifetimes/issue-105507.rs
new file mode 100644
index 00000000000..f46c6b6f21e
--- /dev/null
+++ b/tests/ui/lifetimes/issue-105507.rs
@@ -0,0 +1,43 @@
+// run-rustfix
+//
+#![allow(warnings)]
+struct Wrapper<'a, T: ?Sized>(&'a T);
+
+trait Project {
+    type Projected<'a> where Self: 'a;
+    fn project(this: Wrapper<'_, Self>) -> Self::Projected<'_>;
+}
+trait MyTrait {}
+trait ProjectedMyTrait {}
+
+impl<T> Project for Option<T> {
+    type Projected<'a> = Option<Wrapper<'a, T>> where T: 'a;
+    fn project(this: Wrapper<'_, Self>) -> Self::Projected<'_> {
+        this.0.as_ref().map(Wrapper)
+    }
+}
+
+impl<T: MyTrait> MyTrait for Option<Wrapper<'_, T>> {}
+
+impl<T: ProjectedMyTrait> MyTrait for Wrapper<'_, T> {}
+
+impl<T> ProjectedMyTrait for T
+    where
+        T: Project,
+        for<'a> T::Projected<'a>: MyTrait,
+        //~^ NOTE due to current limitations in the borrow checker, this implies a `'static` lifetime
+        //~| NOTE due to current limitations in the borrow checker, this implies a `'static` lifetime
+{}
+
+fn require_trait<T: MyTrait>(_: T) {}
+
+fn foo<T : MyTrait, U : MyTrait>(wrap: Wrapper<'_, Option<T>>, wrap1: Wrapper<'_, Option<U>>) {
+    //~^ HELP consider restricting the type parameter to the `'static` lifetime
+    //~| HELP consider restricting the type parameter to the `'static` lifetime
+    require_trait(wrap);
+    //~^ ERROR `T` does not live long enough
+    require_trait(wrap1);
+    //~^ ERROR `U` does not live long enough
+}
+
+fn main() {}
diff --git a/tests/ui/lifetimes/issue-105507.stderr b/tests/ui/lifetimes/issue-105507.stderr
new file mode 100644
index 00000000000..44d3a7eb9a4
--- /dev/null
+++ b/tests/ui/lifetimes/issue-105507.stderr
@@ -0,0 +1,34 @@
+error: `T` does not live long enough
+  --> $DIR/issue-105507.rs:37:5
+   |
+LL |     require_trait(wrap);
+   |     ^^^^^^^^^^^^^^^^^^^
+   |
+note: due to current limitations in the borrow checker, this implies a `'static` lifetime
+  --> $DIR/issue-105507.rs:27:35
+   |
+LL |         for<'a> T::Projected<'a>: MyTrait,
+   |                                   ^^^^^^^
+help: consider restricting the type parameter to the `'static` lifetime
+   |
+LL | fn foo<T : MyTrait + 'static, U : MyTrait + 'static>(wrap: Wrapper<'_, Option<T>>, wrap1: Wrapper<'_, Option<U>>) {
+   |                    +++++++++              +++++++++
+
+error: `U` does not live long enough
+  --> $DIR/issue-105507.rs:39:5
+   |
+LL |     require_trait(wrap1);
+   |     ^^^^^^^^^^^^^^^^^^^^
+   |
+note: due to current limitations in the borrow checker, this implies a `'static` lifetime
+  --> $DIR/issue-105507.rs:27:35
+   |
+LL |         for<'a> T::Projected<'a>: MyTrait,
+   |                                   ^^^^^^^
+help: consider restricting the type parameter to the `'static` lifetime
+   |
+LL | fn foo<T : MyTrait + 'static, U : MyTrait + 'static>(wrap: Wrapper<'_, Option<T>>, wrap1: Wrapper<'_, Option<U>>) {
+   |                    +++++++++              +++++++++
+
+error: aborting due to 2 previous errors
+