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swap (std::jthread)

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Concurrency support library
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Initialization of atomic types
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Memory ordering
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friend void swap ( jthread & lhs, jthread & rhs ) noexcept ;
(C++20 起)

std::swap 算法针对 std::jthread 提供重载版本。交换 lhs rhs 的状态。实际调用 lhs. swap ( rhs ) 。此函数对普通的 非限定查找 限定查找 不可见,仅当 std::jthread 作为参数的关联类时,才能通过 实参依赖查找 找到该函数。

目录

参数

lhs, rhs - 待交换状态的 jthread 对象

返回值

(无)

示例

#include <chrono>
#include <iostream>
#include <thread>
void foo()
{
    std::this_thread::sleep_for(std::chrono::seconds(1));
}
void bar()
{
    std::this_thread::sleep_for(std::chrono::seconds(1));
}
int main()
{
    using std::swap;
    std::jthread t1(foo);
    std::jthread t2(bar);
    std::cout << "thread 1 id: " << t1.get_id() << '\n'
              << "thread 2 id: " << t2.get_id() << '\n';
    swap(t1, t2);
    std::cout << "after std::swap(t1, t2):" << '\n'
              << "thread 1 id: " << t1.get_id() << '\n'
              << "thread 2 id: " << t2.get_id() << '\n';
    t1.swap(t2);
    std::cout << "after t1.swap(t2):" << '\n'
              << "thread 1 id: " << t1.get_id() << '\n'
              << "thread 2 id: " << t2.get_id() << '\n';
}

可能的输出:

thread 1 id: 1892
thread 2 id: 2584
after std::swap(t1, t2):
thread 1 id: 2584
thread 2 id: 1892
after t1.swap(t2):
thread 1 id: 1892
thread 2 id: 2584

参见

交换两个 jthread 对象
(公开成员函数)