A Cooperatively Interruptible Joining Thread

std::jthread stands for joining thread. In addition to std::thread from C++11, std::jthread can automatically join the started thread and signal an interrupt. Its characteristics are described in the proposal P0660R8: A Cooperatively Interruptible Joining Thread.

Automatically Joining

Here is the non-intuitive behaviour of std::thread. If a std::thread is still joinable, std::terminate is called in its destructor. A thread thr is joinable if either thr.join() nor thr.detach() was called.

Terminating a still joinable std::thread

// threadJoinable.cpp

#include <iostream>
#include <thread>

int main(){
    
    std::cout << std::endl;
    std::cout << std::boolalpha;
    
    std::thread thr{[]{ std::cout << "Joinable std::thread" << std::endl; }};
    
    std::cout << "thr.joinable(): " << thr.joinable() << std::endl;
    
    std::cout << std::endl;
 ...