Re: Is this safe?

template <typename singleton_type>
void initialize_singleton()
{ singleton_type * & pointer =
singleton_wrapper_private_impl::get_pointer<singleton_type>();
    pointer = new singleton_type;
}

template <typename singleton_type>
singleton_type & singleton_wrapper()
{ //PTHREAD_ONCE_INIT presumably is a const expr,
    //and thus C++03 guarantees this happens before runtime.
    static pthread_once_t init_flag = PTHREAD_ONCE_INIT;

    int x =
        pthread_once(
            &init_flag,
            &initialize_singleton<singleton_type>
    );
    assert(0 == x);
    return *
singleton_wrapper_private_impl::get_pointer<singleton_type>();
}