Method valid

tests/test_class_sh_basic.cpp:20–20

struct uconsumer { // unique_ptr consumer
    std::unique_ptr<atyp> held;
    bool valid() const { return static_cast<bool>(held); }

    void pass_valu(std::unique_ptr<atyp> obj) { held = std::move(obj); }
    void pass_rref(std::unique_ptr<atyp> &&obj) { held = std::move(obj); }