Method SetDummy

util/system/filemap.h:241–244

        return Dummy();
    }
    void SetDummy(const T& n_Dummy) {
        Dummy_.Destroy();
        Dummy_.Reset(new (DummyData()) T(n_Dummy));
    }
    inline char* DummyData() const noexcept {
        return AlignUp((char*)DummyData_);
    }