144 template <class T>
157 template <class T>
160       private details::OptionalStorageBase<sizeof(T),
161                                            std::alignment_of<T>::value> {
172             details::OptionalStorageBase<sizeof(T),
173                                          std::alignment_of<T>::value>;
177     using value_type = T;
181     static_assert(!std::is_same<typename std::decay<T>::type, NulloptT>::value,
183     static_assert(!std::is_same<typename std::decay<T>::type, InplaceT>::value,
185     static_assert(!std::is_reference<T>::value,
194             new (&get()) T(other.get());  in Optional()
199             new (&get()) T(std::move(other.get()));  in Optional()
206                                   std::is_constructible<T, U>::value>>
209             new (&get()) T(other.get());  in Optional()
216                                   std::is_constructible<T, U>::value>>
219             new (&get()) T(std::move(other.get()));  in Optional()
224     Optional(const T& value) : base_flag(true) { new (&get()) T(value); }  in Optional()
226     Optional(T&& value) : base_flag(true) { new (&get()) T(std::move(value)); }  in Optional()
231         new (&get()) T(std::forward<Args>(args)...);  in Optional()
237                       std::is_constructible<T, std::initializer_list<U>>>>
239         new (&get()) T(il);  in Optional()
257                 new (&get()) T(other.get());
277                 new (&get()) T(std::move(other.get()));
288               class = enable_if_convertible<typename std::decay<U>::type, T>>
299                 new (&get()) T(other.get());
310               class = enable_if_convertible<typename std::decay<U>::type, T>>
321                 new (&get()) T(std::move(other.get()));
336                                           T>::value>>
341             new (&get()) T(std::forward<U>(other));
351     T& value() {  in value()
358     constexpr const T& value() const {  in value()
366     T* ptr() {  in ptr()
369     constexpr const T* ptr() const {  in ptr()
374     template <class U = T,
375               class = enable_if_convertible<typename std::decay<U>::type, T>>
376     constexpr T valueOr(U&& defaultValue) const {  in valueOr()
381     T& operator*() {
388     constexpr const T& operator*() const {
396     T* operator->() {
403     constexpr const T* operator->() const {
425               class = enable_if_convertible<typename std::decay<U>::type, T>>
436         new (&get()) T(std::forward<Args>(args)...);  in emplace()
444                       std::is_constructible<T, std::initializer_list<U>>>>
449         new (&get()) T(il);  in emplace()
455     constexpr const T& get() const {  in get()
456         return *reinterpret_cast<const T*>(  in get()
461     T& get() {  in get()
462         return const_cast<T&>(const_cast<const Optional*>(this)->get());  in get()
466     void destruct() { get().T::~T(); }  in destruct()
469 template <class T>
470 Optional<typename std::decay<T>::type> makeOptional(T&& t) {  in makeOptional()
471     return Optional<typename std::decay<T>::type>(std::forward<T>(t));  in makeOptional()
474 template <class T, class... Args>
475 Optional<typename std::decay<T>::type> makeOptional(Args&&... args) {  in makeOptional()
476     return Optional<typename std::decay<T>::type>(kInplace,  in makeOptional()
480 template <class T>
481 bool operator==(const Optional<T>& l, const Optional<T>& r) {
484 template <class T>
485 bool operator==(const Optional<T>& l, NulloptT) {
488 template <class T>
489 bool operator==(NulloptT, const Optional<T>& r) {
492 template <class T>
493 bool operator==(const Optional<T>& l, const T& r) {
496 template <class T>
497 bool operator==(const T& l, const Optional<T>& r) {
501 template <class T>
502 bool operator!=(const Optional<T>& l, const Optional<T>& r) {
505 template <class T>
506 bool operator!=(const Optional<T>& l, NulloptT) {
509 template <class T>
510 bool operator!=(NulloptT, const Optional<T>& r) {
513 template <class T>
514 bool operator!=(const Optional<T>& l, const T& r) {
517 template <class T>
518 bool operator!=(const T& l, const Optional<T>& r) {
522 template <class T>
523 bool operator<(const Optional<T>& l, const Optional<T>& r) {
526 template <class T>
527 bool operator<(const Optional<T>&, NulloptT) {
530 template <class T>
531 bool operator<(NulloptT, const Optional<T>& r) {
534 template <class T>
535 bool operator<(const Optional<T>& l, const T& r) {
538 template <class T>
539 bool operator<(const T& l, const Optional<T>& r) {