Method operator()

tests/test_virtual_functions.cpp:183–187

struct Adder : AdderBase {
    void
    operator()(const Data &first, const Data &second, const DataVisitor &visitor) const override {
        PYBIND11_OVERRIDE_PURE_NAME(
            void, AdderBase, "__call__", operator(), first, second, visitor);
    }
};

static void test_gil() {