Method operator new

tests/test_copy_move.cpp:256–262

    private:
        void *operator new(size_t bytes) {
            void *ptr = std::malloc(bytes);
            if (ptr) {
                return ptr;
            }
            throw std::bad_alloc{};
        }
    };
    py::class_<PrivateOpNew>(m, "PrivateOpNew").def_readonly("value", &PrivateOpNew::value);
    m.def("private_op_new_value", []() { return PrivateOpNew(); });