std::thread::swap

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Thread support library

Threads
thread (C++11)
hardware_destructive_interference_sizehardware_constructive_interference_size (C++17)(C++17)
this_thread namespace
get_id (C++11) yield (C++11)	sleep_for (C++11) sleep_until (C++11)
Mutual exclusion
mutex (C++11) recursive_mutex (C++11) shared_mutex (C++17)	timed_mutex (C++11) recursive_timed_mutex (C++11) shared_timed_mutex (C++14)
Generic lock management
lock_guard (C++11) scoped_lock (C++17) unique_lock (C++11) shared_lock (C++14) defer_lock_ttry_to_lock_tadopt_lock_t (C++11)(C++11)(C++11)	lock (C++11) try_lock (C++11) defer_locktry_to_lockadopt_lock (C++11)(C++11)(C++11) once_flag (C++11) call_once (C++11)
Condition variables
condition_variable (C++11)
condition_variable_any (C++11)
notify_all_at_thread_exit (C++11)
cv_status (C++11)
Futures
promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11)	launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11)

 

std::thread

Member classes

thread::id

Member functions

thread::thread

thread::~thread

thread::operator=

Observers

thread::joinable

thread::get_id

thread::native_handle

thread::hardware_concurrency

Operations

thread::join

thread::detach

thread::swap

Non-member functions

std::swap

 

void swap( thread& other );		(since C++11)

Exchanges the underlying handles of two thread objects.

Parameters

other

-

the thread to swap with

Return value

(none)

Exceptions

noexcept specification:  

noexcept

  

Example

Run this code

#include <iostream>
#include <thread>
#include <chrono>
 
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::thread t1(foo);
    std::thread t2(bar);
 
    std::cout << "thread 1 id: " << t1.get_id() << std::endl;
    std::cout << "thread 2 id: " << t2.get_id() << std::endl;
 
    std::swap(t1, t2);
 
    std::cout << "after std::swap(t1, t2):" << std::endl;
    std::cout << "thread 1 id: " << t1.get_id() << std::endl;
    std::cout << "thread 2 id: " << t2.get_id() << std::endl;
 
    t1.swap(t2);
 
    std::cout << "after t1.swap(t2):" << std::endl;
    std::cout << "thread 1 id: " << t1.get_id() << std::endl;
    std::cout << "thread 2 id: " << t2.get_id() << std::endl;
 
    t1.join();
    t2.join();
}

Possible output:

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

See also

std::swap(std::thread) (C++11)

specializes the std::swap algorithm (function template)