How to create a thread inside a class function? - c++

Question

I am very new to C++.
I have a class, and I want to create a thread inside a class's function. And that thread(function) will call and access the class function and variable as well.
At the beginning I tried to use Pthread, but only work outside a class, if I want to access the class function/variable I got an out of scope error.
I take a look at Boost/thread but it is not desirable because of I don't want to add any other library to my files(for other reason).
I did some research and cannot find any useful answers.
Please give some examples to guide me. Thank you so much!
Attempt using pthread(but I dont know how to deal with the situation I stated above):
#include <pthread.h>
void* print(void* data)
{
std::cout << *((std::string*)data) << "\n";
return NULL; // We could return data here if we wanted to
}
int main()
{
std::string message = "Hello, pthreads!";
pthread_t threadHandle;
pthread_create(&threadHandle, NULL, &print, &message);
// Wait for the thread to finish, then exit
pthread_join(threadHandle, NULL);
return 0;
}

Answer 1

You can pass a static member function to a pthread, and an instance of an object as its argument. The idiom goes something like this:
class Parallel
{
private:
pthread_t thread;
static void * staticEntryPoint(void * c);
void entryPoint();
public:
void start();
};
void Parallel::start()
{
pthread_create(&thread, NULL, Parallel::staticEntryPoint, this);
}
void * Parallel::staticEntryPoint(void * c)
{
((Parallel *) c)->entryPoint();
return NULL;
}
void Parallel::entryPoint()
{
// thread body
}
This is a pthread example. You can probably adapt it to use a std::thread without much difficulty.

Answer 2

#include <thread>
#include <string>
#include <iostream>
class Class
{
public:
Class(const std::string& s) : m_data(s) { }
~Class() { m_thread.join(); }
void runThread() { m_thread = std::thread(&Class::print, this); }
private:
std::string m_data;
std::thread m_thread;
void print() const { std::cout << m_data << '\n'; }
};
int main()
{
Class c("Hello, world!");
c.runThread();
}