Method set

include/pybind11/pytypes.h:2340–2344

public:
    PYBIND11_OBJECT_CVT(set, anyset, PySet_Check, PySet_New)
    set() : anyset(PySet_New(nullptr), stolen_t{}) {
        if (!m_ptr) {
            pybind11_fail("Could not allocate set object!");
        }
    }
    template <typename T>
    bool add(T &&val) /* py-non-const */ {
        return PySet_Add(m_ptr, detail::object_or_cast(std::forward<T>(val)).ptr()) == 0;