std::jthread:: swap

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std::jthread
void swap ( std:: jthread & other ) noexcept ;
(since C++20)

Exchanges the underlying handles of two jthread objects.

Parameters

other - the jthread to swap with

Return value

(none)

Example

Run this code 
#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()
{
    std::jthread t1(foo);
    std::jthread t2(bar);
 
    std::cout << "thread 1 id: " << t1.get_id() << '\n'
              << "thread 2 id: " << t2.get_id() << '\n';
 
    std::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';
 
 
}

Possible output: 

thread 1 id: 140185268262656
thread 2 id: 140185259869952
after std::swap(t1, t2):
thread 1 id: 140185259869952
thread 2 id: 140185268262656
after t1.swap(t2):
thread 1 id: 140185268262656
thread 2 id: 140185259869952

See also

(C++20)
specializes the std::swap algorithm
(function)
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