37   val = std::optional<ExternRef>(std::nullopt);  in TEST()
39   EXPECT_EQ(val.externref(), std::nullopt);  in TEST()
41   val = std::optional<ExternRef>(ExternRef(store, 5));  in TEST()
43   EXPECT_EQ(std::any_cast<int>(val.externref()->data(store)), 5);  in TEST()
47   EXPECT_EQ(std::any_cast<int>(val.externref()->data(store)), 5);  in TEST()
49   val = std::optional<AnyRef>(std::nullopt);  in TEST()
51   EXPECT_EQ(val.anyref(), std::nullopt);  in TEST()
53   val = std::optional<AnyRef>(AnyRef::i31(store, 5));  in TEST()
63   val = std::optional<Func>(std::nullopt);  in TEST()
65   EXPECT_EQ(val.funcref(), std::nullopt);  in TEST()
69               return std::monostate();  in TEST()
72   val = std::optional<Func>(func);  in TEST()
80   std::shared_ptr<std::atomic<bool>> flag_;
83   SetOnDrop() : flag_(std::make_shared<std::atomic<bool>>(false)) {}  in SetOnDrop()
91   const std::shared_ptr<std::atomic<bool>> &flag() { return this->flag_; }  in flag()
95   std::shared_ptr<std::atomic<bool>> flag;  in TEST()
111     ExternRef r(store, std::make_shared<SetOnDrop>(std::move(guard)));  in TEST()
124     ExternRef r(store, std::make_shared<SetOnDrop>(std::move(guard)));  in TEST()
138     ExternRef r(store, std::make_shared<SetOnDrop>(std::move(guard)));  in TEST()
142     r = std::move(r2);  in TEST()
148     v = std::move(v2);  in TEST()