Class functor_with_unique_ptr

test/source/tests/task_tests.cpp:101–113

    }

    class functor_with_unique_ptr {
       private:
        std::unique_ptr<int> up;

       public:
        functor_with_unique_ptr() : up(std::make_unique<int>(12345)) {}
        functor_with_unique_ptr(functor_with_unique_ptr&& rhs) noexcept = default;

        int operator()() noexcept {
            assert(static_cast<bool>(up));
            return *up;
        }
    };

    struct trivially_copiable_destructable {
        int operator()() const {