std::this_thread::get_id

From cppreference.com
< cpplrm; | thread
Defined in header <thread>
std::thread::id get_id() noexcept;
(since C++11)

Returns the id of the current thread.

Parameters

(none)

Return value

id of the current thread

Example

#include <iostream>
#include <thread>
#include <chrono>
#include <mutex>

std::mutex g_display_mutex;

void foo()
{
    std::thread::id this_id = std::this_thread::get_id();

    g_display_mutex.lock();
    std::cout << "thread " << this_id << " sleeping...\n";
    g_display_mutex.unlock();

    std::this_thread::sleep_for(std::chrono::seconds(1));
}

int main()
{
    std::thread t1(foo);
    std::thread t2(foo);

    t1.join();
    t2.join();
}

Possible output:

thread 0x2384b312 sleeping...
thread 0x228a10fc sleeping...

See also

returns the id of the thread
(public member function of std::thread)