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std::jthread::swap

From cppreference.com

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Concurrency support library
Threads
(C++11)
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this_thread namespace
(C++11)
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(C++11)
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(C++11)
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Condition variables
(C++11)
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Latches and Barriers
(C++20)
(C++20)
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(C++26)
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(C++11)
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(C++11)(deprecated in C++20)
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Memory ordering
(C++11)(deprecated in C++26)
Free functions for atomic operations
Free functions for atomic flags
 
 
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

#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

specializes the std::swap algorithm
(function) [edit]