augment equal lifetimes test

Author: aliemjay

tests/ui/type-alias-impl-trait/equal-lifetime-params-not-ok.rs

@@ -24,4 +24,14 @@ mod mod3 {
     //~^ ERROR non-defining opaque type use in defining scope
 }
 
+// This is similar to the previous cases in that 'a is equal to 'static,
+// which is is some sense an implicit parameter to `Opaque`.
+// For example, given a defining use `Opaque<'a> := &'a ()`,
+// it is ambiguous whether `Opaque<'a> := &'a ()` or `Opaque<'a> := &'static ()`
+mod mod4 {
+    type Opaque<'a> = impl super::Trait<'a, 'a>;
+    fn test<'a: 'static>() -> Opaque<'a> {}
+    //~^ ERROR expected generic lifetime parameter, found `'static`
+}
+
 fn main() {}

tests/ui/type-alias-impl-trait/equal-lifetime-params-not-ok.stderr

@@ -46,5 +46,14 @@ note: lifetime used multiple times
 LL |     type Opaque<'a, 'b> = impl super::Trait<'a, 'b>;
    |                 ^^  ^^
 
-error: aborting due to 4 previous errors
+error[E0792]: expected generic lifetime parameter, found `'static`
+  --> $DIR/equal-lifetime-params-not-ok.rs:33:42
+   |
+LL |     type Opaque<'a> = impl super::Trait<'a, 'a>;
+   |                 -- cannot use static lifetime; use a bound lifetime instead or remove the lifetime parameter from the opaque type
+LL |     fn test<'a: 'static>() -> Opaque<'a> {}
+   |                                          ^^
+
+error: aborting due to 5 previous errors
 
+For more information about this error, try `rustc --explain E0792`.