Sharing thread local data between a WrapperClass (wrapper around a thread) object and the thread that it instantiates

I have a Wrapper class similar to something shown below. It wraps a std::thread instance and provides additional functionality on top of it.

class ToShare
{
public:
    void test();
};

thread_local ToShare this_thread_share;

class WrapperThread
{
    std::thread _thread;
public:
    template<typename FunctionType>
    WrapperThread(FunctionType f)
    {
        _thread=std::thread([f]{
            f();
        });
    }
};

Now I want this WrapperClass instance to able to access the same this_thread_share object that the thread that it created accesses. How do I do this?

In other words how do I share a thread local value with the wrapper class instance?