Method str_value

tests/test_virtual_functions.cpp:372–374

    public:
        using OverrideTest::OverrideTest;
        std::string str_value() override {
            PYBIND11_OVERRIDE(std::string, OverrideTest, str_value);
        }
        // Not allowed (enabling the below should hit a static_assert failure): we can't get a
        // reference to a python numeric value, since we only copy values in the numeric type
        // caster: