How can I access my class instance from a boost thread?

boost, c++, multithreading

Solution

Yes, that works. Here's the "real" version, which does in fact print "Foo bar":

#include <boost/make_shared.hpp>
#include <boost/thread.hpp>
#include <boost/bind.hpp>

using namespace boost;

struct FooBar {
    void a();
    void b();
    shared_ptr<thread> m_thread;
    std::string m_test;
};

void FooBar::a() {
    m_test = "Foo bar";
    m_thread = make_shared<thread>(bind(&FooBar::b, this));
}

void FooBar::b() {
    std::cout << m_test;
}

int main() {
    FooBar fb;
    fb.a();
    fb.m_thread->join();
    return 0;
}

The code `cout << test` does not yield any output, because `m_test` is ""

I suspect this is because the object was being destroyed before the thread got around to evaluating the member variable. Note the `join()`, it's very important.

Problem

Original source