C++ åèæå
- C++11
- C++14
- C++17
- C++20
- C++ ç¼è¯å¨æ¯ææ åµè¡¨
- ç¬ç«ä¸å®¿ä¸»å®ç°
- C++ è¯è¨
- C++ å ³é®è¯
- é¢å¤çå¨
- C++ æ ååºå¤´æä»¶
- å ·åè¦æ±
- åè½ç¹æ§æµè¯ (C++20)
- å·¥å ·åº
- ç¨åºæ¯æå·¥å ·
- std::initializer_list
- 彿°å¯¹è±¡
- std::hash
- std::pair
- std::tuple
- std::optional
- std::hash <std::optional>
- std::optional<T>::operator->, std::optional<T>::operator*
- std::optional<T>::operator=
- std::optional<T>::optional
- std::optional<T>::~optional
- std::optional<T>::operator bool, std::optional<T>::has_value
- std::optional<T>::value
- std::optional<T>::value_or
- std::optional<T>::emplace
- std::optional<T>::swap
- std::optional<T>::reset
- operator==, !=, <, <=, >, >=, <=>(std::optional)
- std::make_optional
- std::swap(std::optional)
- std::optional çæ¨å¯¼æå¼
- std::nullopt_t
- std::bad_optional_access
- std::nullopt
- std::apply
- åºç¹æ§æµè¯å® (C++20)
- std::any
- std::variant
- æ ¼å¼ååº (C++20)
- std::integer_sequence
- std::exchange
- std::make_from_tuple
- std::launder
- std::to_chars
- std::from_chars
- std::as_const
- std::source_location
- å忰彿°
- std::bitset
- std::cmp_equal, cmp_not_equal, cmp_less, cmp_greater, cmp_less_equal, cmp_greater_equal
- std::in_range
- std::declval
- std::forward
- std::move
- std::move_if_noexcept
- std::chars_format
- std::piecewise_construct_t
- std::piecewise_construct
- std::in_place, std::in_place_type, std::in_place_index, std::in_place_t, std::in_place_type_t, std::in_place_index_t
- 注é
- ç±»åæ¯æï¼åºæ¬ç±»åãRTTIãç±»åç¹æ§ï¼
- æ¦å¿µåº (C++20)
- é误å¤ç
- 卿å å管ç
- æ¥æåæ¶é´å·¥å ·
- å符串åº
- 容å¨åº
- è¿ä»£å¨åº
- èå´åº (C++20)
- ç®æ³åº
- æ°å¼åº
- è¾å ¥/è¾åºåº
- æä»¶ç³»ç»åº
- æ¬å°ååº
- æ£å表达å¼åº
- ååæä½åº
- çº¿ç¨æ¯æåº
- å®éªæ§ C++ ç¹æ§
- æç¨çèµæº
- ç´¢å¼
- std 符å·ç´¢å¼
- åç¨æ¯æ (C++20)
- C++ å ³é®è¯
ä½ç½®ï¼é¦é¡µ > C++ åèæå >å·¥å ·åº >std::optional > std::swap(std::optional)
std::swap(std::optional)
| å®ä¹äºå¤´æä»¶ <optional>
|
||
| template< class T > void swap( optional<T>& lhs, optional<T>& rhs ) noexcept(/* see below */); |
(C++17 èµ·) | |
对 std::optional éè½½ std::swap ç®æ³ãäº¤æ¢ lhs ä¸ rhs çç¶æãçæå°è°ç¨ lhs.swap(rhs) ã
æ¤éè½½ä» è¥ std::is_move_constructible_v<T> ä¸ std::is_swappable_v<T> ç为true æåä¸éè½½å³è®®ã
åæ°
| lhs, rhs | - | è¦äº¤æ¢ç¶æç optional 对象
|
è¿åå¼
ï¼æ ï¼
å¼å¸¸
noexcept è§å®ï¼Â Â
noexcept(noexcept(lhs.swap(rhs)))
示ä¾
| æ¬èæªå®æ åå ï¼ææ ç¤ºä¾ |
åé
| 交æ¢å
容 (å ¬å¼æå彿°) |