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std:: atomic_flag_test, std:: atomic_flag_test_explicit

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atomic_flag_test atomic_flag_test_explicit
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定义于头文件 <atomic>
bool atomic_flag_test ( const volatile std:: atomic_flag * object ) noexcept ;
(1) (C++20 起)
bool atomic_flag_test ( const std:: atomic_flag * object ) noexcept ;
(2) (C++20 起)
bool atomic_flag_test_explicit ( const volatile std:: atomic_flag * object,
std:: memory_order order ) noexcept ;
(3) (C++20 起)
bool atomic_flag_test_explicit ( const std:: atomic_flag * object,
std:: memory_order order ) noexcept ;
(4) (C++20 起)

原子地读取 * object 的值并返回该值。

1,2) 内存同步顺序为 std:: memory_order_seq_cst 。
3,4) 内存同步顺序为 order 。
如果 order 是 std :: memory_order :: release 和 std :: memory_order :: acq_rel 之一，则行为未定义。

目录

参数

object - 指向要读取的 atomic_flag 对象的指针
order - 内存同步顺序

返回值

原子读取的值。

注释

功能测试 宏 值 标准 功能
__cpp_lib_atomic_flag_test 201907L (C++20) std::atomic_flag::test

示例

本节内容不完整
原因：缺少示例

参见

(C++20)
原子地返回标志的值
( std::atomic_flag 的公开成员函数)