std::atomic_flag::atomic_flag

定义于头文件 `<atomic>`
	(1)
atomic_flag() noexcept = default;			(C++11 起) (C++20 前)
constexpr atomic_flag() noexcept;			(C++20 起)
atomic_flag( const atomic_flag& ) = delete;		(2)	(C++11 起)

构造新的 std::atomic_flag 。

1) 平凡默认构造函数，初始化 std::atomic_flag 为未指定状态。	(C++20 前)
1) 初始化 std::atomic_flag 为清除状态。	(C++20 起)

2) 复制构造函数被删除； std::atomic_flag 不可复制。

另外， std::atomic_flag 能以表达式 ATOMIC_FLAG_INIT 值初始化。对于拥有静态存储期的 atomic_flag ，这保证静态初始化：标志能用于静态对象的构造函数中。此宏不再有必要且被弃用。 (C++20 起)

(C++11)(C++20 中弃用)

将 std::atomic_flag 初始化为 false
(宏常量)

类
atomic (C++11)
atomic_ref (C++20)
函数
atomic_storeatomic_store_explicit (C++11)(C++11)
atomic_loadatomic_load_explicit (C++11)(C++11)
atomic_exchangeatomic_exchange_explicit (C++11)(C++11)
atomic_compare_exchange_weakatomic_compare_exchange_weak_explicitatomic_compare_exchange_strongatomic_compare_exchange_strong_explicit (C++11)(C++11)(C++11)(C++11)
atomic_fetch_addatomic_fetch_add_explicit (C++11)(C++11)
atomic_fetch_subatomic_fetch_sub_explicit (C++11)(C++11)
atomic_fetch_andatomic_fetch_and_explicit (C++11)(C++11)
atomic_fetch_oratomic_fetch_or_explicit (C++11)(C++11)
atomic_fetch_xoratomic_fetch_xor_explicit (C++11)(C++11)
atomic_is_lock_free (C++11)
atomic_waitatomic_wait_explicit (C++20)(C++20)
atomic_notify_one (C++20)
atomic_notify_all (C++20)
原子标志
atomic_flag (C++11)
atomic_flag_test_and_setatomic_flag_test_and_set_explicit (C++11)(C++11)
atomic_flag_clearatomic_flag_clear_explicit (C++11)(C++11)
atomic_flag_testatomic_flag_test_explicit (C++20)(C++20)
atomic_flag_waitatomic_flag_wait_explicit (C++20)(C++20)
atomic_flag_notify_one (C++20)
atomic_flag_notify_all (C++20)
初始化
atomic_init (C++11)(C++20 中弃用)
ATOMIC_VAR_INIT (C++11)(C++20 中弃用)
ATOMIC_FLAG_INIT (C++11)(C++20 中弃用)
内存顺序
memory_order (C++11)
kill_dependency (C++11)
atomic_thread_fence (C++11)
atomic_signal_fence (C++11)