83   constexpr std::optional<int> operator()(int&) { return std::nullopt; }  in operator ()()
91   constexpr std::optional<int> operator()(const int&) { return std::nullopt; }  in operator ()()
99   constexpr std::optional<int> operator()(int&&) { return std::nullopt; }  in operator ()()
107   constexpr std::optional<int> operator()(const int&&) { return std::nullopt; }  in operator ()()
111   constexpr std::optional<int> operator()(int) & { return std::nullopt; }  in operator ()()
119   constexpr std::optional<int> operator()(int) const& { return std::nullopt; }  in operator ()()
127   constexpr std::optional<int> operator()(int) && { return std::nullopt; }  in operator ()()
135   constexpr std::optional<int> operator()(int) const&& { return std::nullopt; }  in operator ()()
155       assert(i.and_then(NOLVal{}) == std::nullopt);  in test_val_types()
165       assert(i.and_then(nl) == std::nullopt);  in test_val_types()
176       assert(i.and_then(NOCLVal{}) == std::nullopt);  in test_val_types()
186       assert(i.and_then(nl) == std::nullopt);  in test_val_types()
197       assert(std::move(i).and_then(NORVal{}) == std::nullopt);  in test_val_types()
205       assert(i.and_then(NORVRefQual{}) == std::nullopt);  in test_val_types()
216       assert(std::move(i).and_then(NOCRVal{}) == std::nullopt);  in test_val_types()
226       assert(i.and_then(std::move(nl)) == std::nullopt);  in test_val_types()