29#ifndef _GLIBCXX_OPTIONAL
30#define _GLIBCXX_OPTIONAL 1
32#pragma GCC system_header
34#if __cplusplus >= 201703L
45#if __cplusplus > 201703L
49namespace std _GLIBCXX_VISIBILITY(default)
51_GLIBCXX_BEGIN_NAMESPACE_VERSION
58#if __cplusplus == 201703L
59# define __cpp_lib_optional 201606L
61# define __cpp_lib_optional 202106L
64 template<
typename _Tp>
75 enum class _Construct { _Token };
78 explicit constexpr nullopt_t(_Construct)
noexcept { }
95 const char*
what() const noexcept
override
96 {
return "bad optional access"; }
100 [[__noreturn__]]
inline void
101 __throw_bad_optional_access()
102 { _GLIBCXX_THROW_OR_ABORT(bad_optional_access()); }
106 template <
typename _Tp>
107 struct _Optional_payload_base
109 using _Stored_type = remove_const_t<_Tp>;
111 _Optional_payload_base() =
default;
112 ~_Optional_payload_base() =
default;
114 template<
typename... _Args>
116 _Optional_payload_base(in_place_t __tag, _Args&&... __args)
117 : _M_payload(__tag,
std::
forward<_Args>(__args)...),
121 template<
typename _Up,
typename... _Args>
125 : _M_payload(__il,
std::
forward<_Args>(__args)...),
132 _Optional_payload_base(
bool __engaged,
133 const _Optional_payload_base& __other)
135 if (__other._M_engaged)
136 this->_M_construct(__other._M_get());
142 _Optional_payload_base(
bool __engaged,
143 _Optional_payload_base&& __other)
145 if (__other._M_engaged)
146 this->_M_construct(
std::move(__other._M_get()));
151 _Optional_payload_base(
const _Optional_payload_base&) =
default;
155 _Optional_payload_base(_Optional_payload_base&&) =
default;
157 _Optional_payload_base&
158 operator=(
const _Optional_payload_base&) =
default;
160 _Optional_payload_base&
161 operator=(_Optional_payload_base&&) =
default;
165 _M_copy_assign(
const _Optional_payload_base& __other)
167 if (this->_M_engaged && __other._M_engaged)
168 this->_M_get() = __other._M_get();
171 if (__other._M_engaged)
172 this->_M_construct(__other._M_get());
180 _M_move_assign(_Optional_payload_base&& __other)
181 noexcept(__and_v<is_nothrow_move_constructible<_Tp>,
182 is_nothrow_move_assignable<_Tp>>)
184 if (this->_M_engaged && __other._M_engaged)
185 this->_M_get() =
std::move(__other._M_get());
188 if (__other._M_engaged)
189 this->_M_construct(
std::move(__other._M_get()));
195 struct _Empty_byte { };
197 template<
typename _Up,
bool = is_trivially_destructible_v<_Up>>
200 constexpr _Storage() noexcept : _M_empty() { }
202 template<
typename... _Args>
204 _Storage(in_place_t, _Args&&... __args)
208 template<
typename _Vp,
typename... _Args>
211 : _M_value(__il,
std::
forward<_Args>(__args)...)
214 _Empty_byte _M_empty;
218 template<
typename _Up>
219 union _Storage<_Up, false>
221 constexpr _Storage() noexcept : _M_empty() { }
223 template<
typename... _Args>
225 _Storage(in_place_t, _Args&&... __args)
229 template<
typename _Vp,
typename... _Args>
232 : _M_value(__il,
std::
forward<_Args>(__args)...)
236 _GLIBCXX20_CONSTEXPR ~_Storage() { }
238 _Empty_byte _M_empty;
242 _Storage<_Stored_type> _M_payload;
244 bool _M_engaged =
false;
246 template<
typename... _Args>
248 _M_construct(_Args&&... __args)
249 noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
252 std::forward<_Args>(__args)...);
253 this->_M_engaged =
true;
257 _M_destroy() noexcept
260 _M_payload._M_value.~_Stored_type();
269 {
return this->_M_payload._M_value; }
272 _M_get() const noexcept
273 {
return this->_M_payload._M_value; }
279 if (this->_M_engaged)
285 template <
typename _Tp,
287 is_trivially_destructible_v<_Tp>,
289 is_trivially_copy_assignable_v<_Tp>
290 && is_trivially_copy_constructible_v<_Tp>,
292 is_trivially_move_assignable_v<_Tp>
293 && is_trivially_move_constructible_v<_Tp>>
294 struct _Optional_payload;
297 template <
typename _Tp>
298 struct _Optional_payload<_Tp, true, true, true>
299 : _Optional_payload_base<_Tp>
301 using _Optional_payload_base<_Tp>::_Optional_payload_base;
303 _Optional_payload() =
default;
307 template <
typename _Tp>
308 struct _Optional_payload<_Tp, true, false, true>
309 : _Optional_payload_base<_Tp>
311 using _Optional_payload_base<_Tp>::_Optional_payload_base;
313 _Optional_payload() =
default;
314 ~_Optional_payload() =
default;
315 _Optional_payload(
const _Optional_payload&) =
default;
316 _Optional_payload(_Optional_payload&&) =
default;
317 _Optional_payload& operator=(_Optional_payload&&) =
default;
322 operator=(
const _Optional_payload& __other)
324 this->_M_copy_assign(__other);
330 template <
typename _Tp>
331 struct _Optional_payload<_Tp, true, true, false>
332 : _Optional_payload_base<_Tp>
334 using _Optional_payload_base<_Tp>::_Optional_payload_base;
336 _Optional_payload() =
default;
337 ~_Optional_payload() =
default;
338 _Optional_payload(
const _Optional_payload&) =
default;
339 _Optional_payload(_Optional_payload&&) =
default;
340 _Optional_payload& operator=(
const _Optional_payload&) =
default;
345 operator=(_Optional_payload&& __other)
346 noexcept(__and_v<is_nothrow_move_constructible<_Tp>,
347 is_nothrow_move_assignable<_Tp>>)
349 this->_M_move_assign(
std::move(__other));
355 template <
typename _Tp>
356 struct _Optional_payload<_Tp, true, false, false>
357 : _Optional_payload_base<_Tp>
359 using _Optional_payload_base<_Tp>::_Optional_payload_base;
361 _Optional_payload() =
default;
362 ~_Optional_payload() =
default;
363 _Optional_payload(
const _Optional_payload&) =
default;
364 _Optional_payload(_Optional_payload&&) =
default;
369 operator=(
const _Optional_payload& __other)
371 this->_M_copy_assign(__other);
378 operator=(_Optional_payload&& __other)
379 noexcept(__and_v<is_nothrow_move_constructible<_Tp>,
380 is_nothrow_move_assignable<_Tp>>)
382 this->_M_move_assign(
std::move(__other));
388 template <
typename _Tp,
bool _Copy,
bool _Move>
389 struct _Optional_payload<_Tp, false, _Copy, _Move>
390 : _Optional_payload<_Tp, true, false, false>
393 using _Optional_payload<_Tp,
true,
false,
false>::_Optional_payload;
394 _Optional_payload() =
default;
395 _Optional_payload(
const _Optional_payload&) =
default;
396 _Optional_payload(_Optional_payload&&) =
default;
397 _Optional_payload& operator=(
const _Optional_payload&) =
default;
398 _Optional_payload& operator=(_Optional_payload&&) =
default;
401 _GLIBCXX20_CONSTEXPR ~_Optional_payload() { this->_M_reset(); }
406 template<
typename _Tp,
typename _Dp>
407 class _Optional_base_impl
410 using _Stored_type = remove_const_t<_Tp>;
414 template<
typename... _Args>
416 _M_construct(_Args&&... __args)
417 noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
419 static_cast<_Dp*
>(
this)->_M_payload._M_construct(
420 std::forward<_Args>(__args)...);
424 _M_destruct() noexcept
425 {
static_cast<_Dp*
>(
this)->_M_payload._M_destroy(); }
430 {
static_cast<_Dp*
>(
this)->_M_payload._M_reset(); }
432 constexpr bool _M_is_engaged() const noexcept
433 {
return static_cast<const _Dp*
>(
this)->_M_payload._M_engaged; }
439 __glibcxx_assert(this->_M_is_engaged());
440 return static_cast<_Dp*
>(
this)->_M_payload._M_get();
444 _M_get() const noexcept
446 __glibcxx_assert(this->_M_is_engaged());
447 return static_cast<const _Dp*
>(
this)->_M_payload._M_get();
469 template<
typename _Tp,
470 bool = is_trivially_copy_constructible_v<_Tp>,
471 bool = is_trivially_move_constructible_v<_Tp>>
473 : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
479 template<
typename... _Args,
480 enable_if_t<is_constructible_v<_Tp, _Args...>,
bool> =
false>
483 : _M_payload(in_place, std::forward<_Args>(__args)...)
486 template<
typename _Up,
typename... _Args,
489 _Args...>,
bool> =
false>
494 : _M_payload(in_place, __il, std::forward<_Args>(__args)...)
500 : _M_payload(__other._M_payload._M_engaged, __other._M_payload)
505 noexcept(is_nothrow_move_constructible_v<_Tp>)
506 : _M_payload(__other._M_payload._M_engaged,
514 _Optional_payload<_Tp> _M_payload;
517 template<
typename _Tp>
519 : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
525 template<
typename... _Args,
526 enable_if_t<is_constructible_v<_Tp, _Args...>,
bool> =
false>
529 : _M_payload(in_place,
std::
forward<_Args>(__args)...)
532 template<
typename _Up,
typename... _Args,
534 initializer_list<_Up>&,
535 _Args...>,
bool> =
false>
537 _Optional_base(in_place_t,
538 initializer_list<_Up> __il,
540 : _M_payload(in_place, __il,
std::
forward<_Args>(__args)...)
544 constexpr _Optional_base(
const _Optional_base& __other)
545 : _M_payload(__other._M_payload._M_engaged, __other._M_payload)
548 constexpr _Optional_base(_Optional_base&& __other) =
default;
551 _Optional_base& operator=(
const _Optional_base&) =
default;
552 _Optional_base& operator=(_Optional_base&&) =
default;
554 _Optional_payload<_Tp> _M_payload;
557 template<
typename _Tp>
558 struct _Optional_base<_Tp, true, false>
559 : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
562 constexpr _Optional_base() =
default;
565 template<
typename... _Args,
566 enable_if_t<is_constructible_v<_Tp, _Args...>,
bool> =
false>
568 _Optional_base(in_place_t, _Args&&... __args)
569 : _M_payload(in_place,
std::
forward<_Args>(__args)...)
572 template<
typename _Up,
typename... _Args,
574 initializer_list<_Up>&,
575 _Args...>,
bool> =
false>
577 _Optional_base(in_place_t,
578 initializer_list<_Up> __il,
580 : _M_payload(in_place, __il,
std::
forward<_Args>(__args)...)
584 constexpr _Optional_base(
const _Optional_base& __other) =
default;
587 _Optional_base(_Optional_base&& __other)
588 noexcept(is_nothrow_move_constructible_v<_Tp>)
589 : _M_payload(__other._M_payload._M_engaged,
594 _Optional_base& operator=(
const _Optional_base&) =
default;
595 _Optional_base& operator=(_Optional_base&&) =
default;
597 _Optional_payload<_Tp> _M_payload;
600 template<
typename _Tp>
601 struct _Optional_base<_Tp, true, true>
602 : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
605 constexpr _Optional_base() =
default;
608 template<
typename... _Args,
609 enable_if_t<is_constructible_v<_Tp, _Args...>,
bool> =
false>
611 _Optional_base(in_place_t, _Args&&... __args)
612 : _M_payload(in_place,
std::
forward<_Args>(__args)...)
615 template<
typename _Up,
typename... _Args,
617 initializer_list<_Up>&,
618 _Args...>,
bool> =
false>
620 _Optional_base(in_place_t,
621 initializer_list<_Up> __il,
623 : _M_payload(in_place, __il,
std::
forward<_Args>(__args)...)
627 constexpr _Optional_base(
const _Optional_base& __other) =
default;
628 constexpr _Optional_base(_Optional_base&& __other) =
default;
631 _Optional_base& operator=(
const _Optional_base&) =
default;
632 _Optional_base& operator=(_Optional_base&&) =
default;
634 _Optional_payload<_Tp> _M_payload;
637 template<
typename _Tp>
640 template<
typename _Tp,
typename _Up>
641 using __converts_from_optional =
642 __or_<is_constructible<_Tp, const optional<_Up>&>,
643 is_constructible<_Tp, optional<_Up>&>,
644 is_constructible<_Tp, const optional<_Up>&&>,
645 is_constructible<_Tp, optional<_Up>&&>,
646 is_convertible<const optional<_Up>&, _Tp>,
647 is_convertible<optional<_Up>&, _Tp>,
648 is_convertible<const optional<_Up>&&, _Tp>,
649 is_convertible<optional<_Up>&&, _Tp>>;
651 template<
typename _Tp,
typename _Up>
652 using __assigns_from_optional =
653 __or_<is_assignable<_Tp&, const optional<_Up>&>,
654 is_assignable<_Tp&, optional<_Up>&>,
655 is_assignable<_Tp&, const optional<_Up>&&>,
656 is_assignable<_Tp&, optional<_Up>&&>>;
661 template<
typename _Tp>
664 private _Enable_copy_move<
666 is_copy_constructible_v<_Tp>,
668 __and_v<is_copy_constructible<_Tp>, is_copy_assignable<_Tp>>,
670 is_move_constructible_v<_Tp>,
672 __and_v<is_move_constructible<_Tp>, is_move_assignable<_Tp>>,
676 static_assert(!is_same_v<remove_cv_t<_Tp>,
nullopt_t>);
677 static_assert(!is_same_v<remove_cv_t<_Tp>, in_place_t>);
678 static_assert(!is_reference_v<_Tp>);
684 template<
typename _Up>
685 using __not_self = __not_<is_same<optional, __remove_cvref_t<_Up>>>;
686 template<
typename _Up>
687 using __not_tag = __not_<is_same<in_place_t, __remove_cvref_t<_Up>>>;
688 template<
typename... _Cond>
689 using _Requires =
enable_if_t<__and_v<_Cond...>,
bool>;
692 using value_type = _Tp;
699 template<
typename _Up = _Tp,
700 _Requires<__not_self<_Up>, __not_tag<_Up>,
705 noexcept(is_nothrow_constructible_v<_Tp, _Up>)
706 :
_Base(std::in_place, std::forward<_Up>(__t)) { }
708 template<
typename _Up = _Tp,
709 _Requires<__not_self<_Up>, __not_tag<_Up>,
711 __not_<is_convertible<_Up, _Tp>>> =
false>
714 noexcept(is_nothrow_constructible_v<_Tp, _Up>)
715 :
_Base(std::in_place, std::forward<_Up>(__t)) { }
717 template<
typename _Up,
718 _Requires<__not_<is_same<_Tp, _Up>>,
721 __not_<__converts_from_optional<_Tp, _Up>>> =
true>
724 noexcept(is_nothrow_constructible_v<_Tp, const _Up&>)
730 template<
typename _Up,
731 _Requires<__not_<is_same<_Tp, _Up>>,
733 __not_<is_convertible<const _Up&, _Tp>>,
734 __not_<__converts_from_optional<_Tp, _Up>>> =
false>
737 noexcept(is_nothrow_constructible_v<_Tp, const _Up&>)
743 template<
typename _Up,
744 _Requires<__not_<is_same<_Tp, _Up>>,
747 __not_<__converts_from_optional<_Tp, _Up>>> =
true>
750 noexcept(is_nothrow_constructible_v<_Tp, _Up>)
756 template<
typename _Up,
757 _Requires<__not_<is_same<_Tp, _Up>>,
759 __not_<is_convertible<_Up, _Tp>>,
760 __not_<__converts_from_optional<_Tp, _Up>>> =
false>
763 noexcept(is_nothrow_constructible_v<_Tp, _Up>)
769 template<
typename... _Args,
772 optional(in_place_t, _Args&&... __args)
773 noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
774 :
_Base(std::in_place, std::forward<_Args>(__args)...) { }
776 template<
typename _Up,
typename... _Args,
782 noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&,
784 :
_Base(std::in_place, __il, std::forward<_Args>(__args)...) { }
795 template<
typename _Up = _Tp>
798 __not_<__and_<is_scalar<_Tp>,
804 noexcept(__and_v<is_nothrow_constructible<_Tp, _Up>,
807 if (this->_M_is_engaged())
808 this->_M_get() = std::forward<_Up>(__u);
810 this->_M_construct(std::forward<_Up>(__u));
815 template<
typename _Up>
820 __not_<__converts_from_optional<_Tp, _Up>>,
821 __not_<__assigns_from_optional<_Tp, _Up>>>,
824 noexcept(__and_v<is_nothrow_constructible<_Tp, const _Up&>,
829 if (this->_M_is_engaged())
830 this->_M_get() = *__u;
832 this->_M_construct(*__u);
841 template<
typename _Up>
846 __not_<__converts_from_optional<_Tp, _Up>>,
847 __not_<__assigns_from_optional<_Tp, _Up>>>,
850 noexcept(__and_v<is_nothrow_constructible<_Tp, _Up>,
855 if (this->_M_is_engaged())
868 template<
typename... _Args>
870 enable_if_t<is_constructible_v<_Tp, _Args...>, _Tp&>
871 emplace(_Args&&... __args)
872 noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
875 this->_M_construct(std::forward<_Args>(__args)...);
876 return this->_M_get();
879 template<
typename _Up,
typename... _Args>
884 noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&,
888 this->_M_construct(__il, std::forward<_Args>(__args)...);
889 return this->_M_get();
895 _GLIBCXX20_CONSTEXPR
void
897 noexcept(is_nothrow_move_constructible_v<_Tp>
898 && is_nothrow_swappable_v<_Tp>)
902 if (this->_M_is_engaged() && __other._M_is_engaged())
903 swap(this->_M_get(), __other._M_get());
904 else if (this->_M_is_engaged())
906 __other._M_construct(
std::move(this->_M_get()));
909 else if (__other._M_is_engaged())
911 this->_M_construct(
std::move(__other._M_get()));
912 __other._M_destruct();
918 operator->()
const noexcept
922 operator->()
noexcept
926 operator*()
const&
noexcept
927 {
return this->_M_get(); }
930 operator*()&
noexcept
931 {
return this->_M_get(); }
934 operator*()&&
noexcept
937 constexpr const _Tp&&
938 operator*()
const&&
noexcept
941 constexpr explicit operator bool()
const noexcept
942 {
return this->_M_is_engaged(); }
944 constexpr bool has_value()
const noexcept
945 {
return this->_M_is_engaged(); }
950 if (this->_M_is_engaged())
951 return this->_M_get();
952 __throw_bad_optional_access();
958 if (this->_M_is_engaged())
959 return this->_M_get();
960 __throw_bad_optional_access();
966 if (this->_M_is_engaged())
968 __throw_bad_optional_access();
971 constexpr const _Tp&&
974 if (this->_M_is_engaged())
976 __throw_bad_optional_access();
979 template<
typename _Up>
981 value_or(_Up&& __u)
const&
983 static_assert(is_copy_constructible_v<_Tp>);
984 static_assert(is_convertible_v<_Up&&, _Tp>);
986 if (this->_M_is_engaged())
987 return this->_M_get();
989 return static_cast<_Tp
>(std::forward<_Up>(__u));
992 template<
typename _Up>
994 value_or(_Up&& __u) &&
996 static_assert(is_move_constructible_v<_Tp>);
997 static_assert(is_convertible_v<_Up&&, _Tp>);
999 if (this->_M_is_engaged())
1002 return static_cast<_Tp
>(std::forward<_Up>(__u));
1005 _GLIBCXX20_CONSTEXPR
void reset()
noexcept { this->_M_reset(); }
1008 template<
typename _Tp>
1009 using __optional_relop_t =
1012 template<
typename _Tp,
typename _Up>
1013 using __optional_eq_t = __optional_relop_t<
1014 decltype(std::declval<const _Tp&>() == std::declval<const _Up&>())
1017 template<
typename _Tp,
typename _Up>
1018 using __optional_ne_t = __optional_relop_t<
1019 decltype(std::declval<const _Tp&>() != std::declval<const _Up&>())
1022 template<
typename _Tp,
typename _Up>
1023 using __optional_lt_t = __optional_relop_t<
1024 decltype(std::declval<const _Tp&>() < std::declval<const _Up&>())
1027 template<
typename _Tp,
typename _Up>
1028 using __optional_gt_t = __optional_relop_t<
1029 decltype(std::declval<const _Tp&>() > std::declval<const _Up&>())
1032 template<
typename _Tp,
typename _Up>
1033 using __optional_le_t = __optional_relop_t<
1034 decltype(std::declval<const _Tp&>() <= std::declval<const _Up&>())
1037 template<
typename _Tp,
typename _Up>
1038 using __optional_ge_t = __optional_relop_t<
1039 decltype(std::declval<const _Tp&>() >= std::declval<const _Up&>())
1043 template<
typename _Tp,
typename _Up>
1046 -> __optional_eq_t<_Tp, _Up>
1048 return static_cast<bool>(__lhs) ==
static_cast<bool>(__rhs)
1049 && (!__lhs || *__lhs == *__rhs);
1052 template<
typename _Tp,
typename _Up>
1054 operator!=(
const optional<_Tp>& __lhs,
const optional<_Up>& __rhs)
1055 -> __optional_ne_t<_Tp, _Up>
1057 return static_cast<bool>(__lhs) !=
static_cast<bool>(__rhs)
1058 || (
static_cast<bool>(__lhs) && *__lhs != *__rhs);
1061 template<
typename _Tp,
typename _Up>
1063 operator<(
const optional<_Tp>& __lhs,
const optional<_Up>& __rhs)
1064 -> __optional_lt_t<_Tp, _Up>
1066 return static_cast<bool>(__rhs) && (!__lhs || *__lhs < *__rhs);
1069 template<
typename _Tp,
typename _Up>
1071 operator>(
const optional<_Tp>& __lhs,
const optional<_Up>& __rhs)
1072 -> __optional_gt_t<_Tp, _Up>
1074 return static_cast<bool>(__lhs) && (!__rhs || *__lhs > *__rhs);
1077 template<
typename _Tp,
typename _Up>
1079 operator<=(
const optional<_Tp>& __lhs,
const optional<_Up>& __rhs)
1080 -> __optional_le_t<_Tp, _Up>
1082 return !__lhs || (
static_cast<bool>(__rhs) && *__lhs <= *__rhs);
1085 template<
typename _Tp,
typename _Up>
1087 operator>=(
const optional<_Tp>& __lhs,
const optional<_Up>& __rhs)
1088 -> __optional_ge_t<_Tp, _Up>
1090 return !__rhs || (
static_cast<bool>(__lhs) && *__lhs >= *__rhs);
1093#ifdef __cpp_lib_three_way_comparison
1094 template<
typename _Tp, three_way_comparable_with<_Tp> _Up>
1095 constexpr compare_three_way_result_t<_Tp, _Up>
1096 operator<=>(
const optional<_Tp>& __x,
const optional<_Up>& __y)
1098 return __x && __y ? *__x <=> *__y : bool(__x) <=> bool(__y);
1103 template<
typename _Tp>
1105 operator==(
const optional<_Tp>& __lhs, nullopt_t)
noexcept
1108#ifdef __cpp_lib_three_way_comparison
1109 template<
typename _Tp>
1110 constexpr strong_ordering
1111 operator<=>(
const optional<_Tp>& __x, nullopt_t)
noexcept
1112 {
return bool(__x) <=>
false; }
1114 template<
typename _Tp>
1116 operator==(nullopt_t,
const optional<_Tp>& __rhs)
noexcept
1119 template<
typename _Tp>
1121 operator!=(
const optional<_Tp>& __lhs, nullopt_t)
noexcept
1122 {
return static_cast<bool>(__lhs); }
1124 template<
typename _Tp>
1126 operator!=(nullopt_t,
const optional<_Tp>& __rhs)
noexcept
1127 {
return static_cast<bool>(__rhs); }
1129 template<
typename _Tp>
1131 operator<(
const optional<_Tp>& , nullopt_t)
noexcept
1134 template<
typename _Tp>
1136 operator<(nullopt_t,
const optional<_Tp>& __rhs)
noexcept
1137 {
return static_cast<bool>(__rhs); }
1139 template<
typename _Tp>
1141 operator>(
const optional<_Tp>& __lhs, nullopt_t)
noexcept
1142 {
return static_cast<bool>(__lhs); }
1144 template<
typename _Tp>
1146 operator>(nullopt_t,
const optional<_Tp>& )
noexcept
1149 template<
typename _Tp>
1151 operator<=(
const optional<_Tp>& __lhs, nullopt_t)
noexcept
1154 template<
typename _Tp>
1156 operator<=(nullopt_t,
const optional<_Tp>& )
noexcept
1159 template<
typename _Tp>
1161 operator>=(
const optional<_Tp>& , nullopt_t)
noexcept
1164 template<
typename _Tp>
1166 operator>=(nullopt_t,
const optional<_Tp>& __rhs)
noexcept
1171 template<
typename _Tp,
typename _Up>
1173 operator==(
const optional<_Tp>& __lhs,
const _Up& __rhs)
1174 -> __optional_eq_t<_Tp, _Up>
1175 {
return __lhs && *__lhs == __rhs; }
1177 template<
typename _Tp,
typename _Up>
1179 operator==(
const _Up& __lhs,
const optional<_Tp>& __rhs)
1180 -> __optional_eq_t<_Up, _Tp>
1181 {
return __rhs && __lhs == *__rhs; }
1183 template<
typename _Tp,
typename _Up>
1185 operator!=(
const optional<_Tp>& __lhs,
const _Up& __rhs)
1186 -> __optional_ne_t<_Tp, _Up>
1187 {
return !__lhs || *__lhs != __rhs; }
1189 template<
typename _Tp,
typename _Up>
1191 operator!=(
const _Up& __lhs,
const optional<_Tp>& __rhs)
1192 -> __optional_ne_t<_Up, _Tp>
1193 {
return !__rhs || __lhs != *__rhs; }
1195 template<
typename _Tp,
typename _Up>
1197 operator<(
const optional<_Tp>& __lhs,
const _Up& __rhs)
1198 -> __optional_lt_t<_Tp, _Up>
1199 {
return !__lhs || *__lhs < __rhs; }
1201 template<
typename _Tp,
typename _Up>
1203 operator<(
const _Up& __lhs,
const optional<_Tp>& __rhs)
1204 -> __optional_lt_t<_Up, _Tp>
1205 {
return __rhs && __lhs < *__rhs; }
1207 template<
typename _Tp,
typename _Up>
1209 operator>(
const optional<_Tp>& __lhs,
const _Up& __rhs)
1210 -> __optional_gt_t<_Tp, _Up>
1211 {
return __lhs && *__lhs > __rhs; }
1213 template<
typename _Tp,
typename _Up>
1215 operator>(
const _Up& __lhs,
const optional<_Tp>& __rhs)
1216 -> __optional_gt_t<_Up, _Tp>
1217 {
return !__rhs || __lhs > *__rhs; }
1219 template<
typename _Tp,
typename _Up>
1221 operator<=(
const optional<_Tp>& __lhs,
const _Up& __rhs)
1222 -> __optional_le_t<_Tp, _Up>
1223 {
return !__lhs || *__lhs <= __rhs; }
1225 template<
typename _Tp,
typename _Up>
1227 operator<=(
const _Up& __lhs,
const optional<_Tp>& __rhs)
1228 -> __optional_le_t<_Up, _Tp>
1229 {
return __rhs && __lhs <= *__rhs; }
1231 template<
typename _Tp,
typename _Up>
1233 operator>=(
const optional<_Tp>& __lhs,
const _Up& __rhs)
1234 -> __optional_ge_t<_Tp, _Up>
1235 {
return __lhs && *__lhs >= __rhs; }
1237 template<
typename _Tp,
typename _Up>
1239 operator>=(
const _Up& __lhs,
const optional<_Tp>& __rhs)
1240 -> __optional_ge_t<_Up, _Tp>
1241 {
return !__rhs || __lhs >= *__rhs; }
1243#ifdef __cpp_lib_three_way_comparison
1244 template<
typename _Tp>
1245 inline constexpr bool __is_optional_v =
false;
1246 template<
typename _Tp>
1247 inline constexpr bool __is_optional_v<optional<_Tp>> =
true;
1249 template<
typename _Tp,
typename _Up>
1250 requires (!__is_optional_v<_Up>)
1251 && three_way_comparable_with<_Tp, _Up>
1252 constexpr compare_three_way_result_t<_Tp, _Up>
1253 operator<=>(
const optional<_Tp>& __x,
const _Up& __v)
1254 {
return bool(__x) ? *__x <=> __v : strong_ordering::less; }
1261 template<
typename _Tp>
1262 _GLIBCXX20_CONSTEXPR
1263 inline enable_if_t<is_move_constructible_v<_Tp> && is_swappable_v<_Tp>>
1264 swap(optional<_Tp>& __lhs, optional<_Tp>& __rhs)
1265 noexcept(
noexcept(__lhs.swap(__rhs)))
1266 { __lhs.swap(__rhs); }
1268 template<
typename _Tp>
1269 enable_if_t<!(is_move_constructible_v<_Tp> && is_swappable_v<_Tp>)>
1270 swap(optional<_Tp>&, optional<_Tp>&) =
delete;
1272 template<
typename _Tp>
1274 enable_if_t<is_constructible_v<decay_t<_Tp>, _Tp>,
1275 optional<decay_t<_Tp>>>
1276 make_optional(_Tp&& __t)
1277 noexcept(is_nothrow_constructible_v<optional<decay_t<_Tp>>, _Tp>)
1278 {
return optional<decay_t<_Tp>>{ std::forward<_Tp>(__t) }; }
1280 template<
typename _Tp,
typename... _Args>
1284 make_optional(_Args&&... __args)
1285 noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
1286 {
return optional<_Tp>{ in_place, std::forward<_Args>(__args)... }; }
1288 template<
typename _Tp,
typename _Up,
typename... _Args>
1290 enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
1292 make_optional(initializer_list<_Up> __il, _Args&&... __args)
1293 noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>)
1294 {
return optional<_Tp>{ in_place, __il, std::forward<_Args>(__args)... }; }
1298 template<
typename _Tp,
typename _Up = remove_const_t<_Tp>,
1299 bool = __poison_hash<_Up>::__enable_hash_call>
1300 struct __optional_hash_call_base
1303 operator()(
const optional<_Tp>& __t)
const
1304 noexcept(
noexcept(hash<_Up>{}(*__t)))
1308 constexpr size_t __magic_disengaged_hash =
static_cast<size_t>(-3333);
1309 return __t ? hash<_Up>{}(*__t) : __magic_disengaged_hash;
1313 template<
typename _Tp,
typename _Up>
1314 struct __optional_hash_call_base<_Tp, _Up, false> {};
1316 template<
typename _Tp>
1317 struct hash<optional<_Tp>>
1318 :
private __poison_hash<remove_const_t<_Tp>>,
1319 public __optional_hash_call_base<_Tp>
1321 using result_type [[__deprecated__]] = size_t;
1322 using argument_type [[__deprecated__]] = optional<_Tp>;
1325 template<
typename _Tp>
1326 struct __is_fast_hash<hash<optional<_Tp>>> : __is_fast_hash<hash<_Tp>>
1331#if __cpp_deduction_guides >= 201606
1332 template <
typename _Tp> optional(_Tp) -> optional<_Tp>;
1335_GLIBCXX_END_NAMESPACE_VERSION
typename enable_if< _Cond, _Tp >::type enable_if_t
Alias template for enable_if.
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
constexpr nullopt_t nullopt
Tag to disengage optional objects.
void swap(any &__x, any &__y) noexcept
Exchange the states of two any objects.
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
ISO C++ entities toplevel namespace is std.
constexpr void _Construct(_Tp *__p, _Args &&... __args)
Class template for optional values.
Tag type to disengage optional objects.
Exception class thrown when a disengaged optional object is dereferenced.
const char * what() const noexcept override
Class template that provides copy/move constructors of optional.
Base class for all library exceptions.