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    std::thread::joinable

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    Revision as of 03:23, 14 April 2013 by Korval (talk | contribs) (Just making that point clear.)
     
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    std::thread
     
    bool joinable();
    		(since C++11)

    Checks if the thread object identifies an active thread of execution. Specifically, returns true if get_id() != std::thread::id(). So a default constructed thread is not joinable.

    Parameters

    (none)

    Return value

    true if the thread object identifies an active thread of execution, false otherwise

    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));
}

int main()
{
    std::thread t;
    std::cout << "before starting, joinable: " << t.joinable() << '\n';

    t = std::thread(foo);
    std::cout << "after starting, joinable: " << t.joinable() << '\n';

    t.join();
}

    Output: 

    before starting, joinable: 0
after starting, joinable: 1

    See also

    		 returns the id of the thread
    (public member function of std::{{{1}}}) [edit]
    		waits for the thread to finish its execution
    (public member function of std::{{{1}}}) [edit]
    		permits the thread to execute independently from the thread handle
    (public member function of std::{{{1}}}) [edit]