resolve types in closure capture copy detection

Author: HKalbasi

crates/hir-ty/src/infer/closure.rs

@@ -710,14 +710,14 @@ impl InferenceContext<'_> {
         false
     }
 
-    fn is_ty_copy(&self, ty: Ty) -> bool {
+    fn is_ty_copy(&mut self, ty: Ty) -> bool {
         if let TyKind::Closure(id, _) = ty.kind(Interner) {
             // FIXME: We handle closure as a special case, since chalk consider every closure as copy. We
             // should probably let chalk know which closures are copy, but I don't know how doing it
             // without creating query cycles.
             return self.result.closure_info.get(id).map(|x| x.1 == FnTrait::Fn).unwrap_or(true);
         }
-        ty.is_copy(self.db, self.owner)
+        self.table.resolve_completely(ty).is_copy(self.db, self.owner)
     }
 
     fn select_from_expr(&mut self, expr: ExprId) {

crates/ide/src/hover/tests.rs

@@ -301,6 +301,33 @@ fn main() {
             * `(*x.f2.0.0).f` by mutable borrow
         "#]],
     );
+    check(
+        r#"
+//- minicore: copy, option
+
+fn do_char(c: char) {}
+
+fn main() {
+    let x = None;
+    let y = |$0| {
+        match x {
+            Some(c) => do_char(c),
+            None => x = None,
+        }
+    };
+}
+"#,
+        expect![[r#"
+            *|*
+            ```rust
+            {closure#0} // size = 8, align = 8
+            impl FnMut()
+            ```
+
+            ## Captures
+            * `x` by mutable borrow
+        "#]],
+    );
 }
 
 #[test]