std::thread::joinable - cppreference.com (original) (raw)

| bool joinable() const noexcept; | | (since C++11) | | ------------------------------- | | ------------- |

Checks if the std::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.

A thread that has finished executing code, but has not yet been joined is still considered an active thread of execution and is therefore joinable.

[edit] Parameters

(none)

[edit] Return value

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

[edit] Example

Output:

before starting, joinable: false after starting, joinable: true after joining, joinable: false after detaching, joinable: false

[edit] References

• C++23 standard (ISO/IEC 14882:2024):

• 33.4.3.6 Members [thread.thread.member]

• C++20 standard (ISO/IEC 14882:2020):

• 32.4.2.5 Members [thread.thread.member]

• C++17 standard (ISO/IEC 14882:2017):

• 33.3.2.5 thread members [thread.thread.member]

• C++14 standard (ISO/IEC 14882:2014):

• 30.3.1.5 thread members [thread.thread.member]

• C++11 standard (ISO/IEC 14882:2011):

• 30.3.1.5 thread members [thread.thread.member]

[edit] See also

| | returns the id of the thread (public member function) [edit] | | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | waits for the thread to finish its execution (public member function) [edit] | | | permits the thread to execute independently from the thread handle (public member function) [edit] |